Metrics details
where individuals occupy a subset of a population’s wider dietary niche
is a key factor determining a species resilience against environmental change
as well as associated underlying social learning
Using a multigenerational dataset of female European brown bears (Ursus arctos) followed since birth
we discerned the relative contributions of environmental similarity
and offspring social learning from the mother to individual specialization
Individual specialization accounted for 43% of phenotypic variation and spanned half a trophic position
with individual diets ranging from omnivorous to carnivorous
The main determinants of dietary specialization were social learning during rearing (13%)
and permanent between-individual effects (9%)
whereas the contribution of genetic heritability (3%) was negligible
The trophic position of offspring closely resembled the trophic position of their mothers during the first 3–4 years of independence
but waned with increasing time since separation
Our study shows that social learning and maternal effects were more important for individual dietary specialization than environmental composition
We propose a tighter integration of social effects into studies of range expansion and habitat selection under global change
how individual variation in dietary specialization emerges and is maintained within populations has
We here provide a study to attribute individual variation in the dietary specialization to its sources
so it is reasonable to predict that brown bear offspring learn their dietary niche from their mothers
these differences may be maintained in the population through offspring social learning from the mother (hereafter “social learning”)
A Bear hair generally grows from June until October and stable-nitrogen isotopes (δ15N) reflect cumulative diet intake during the period of hair growth
followed by emergence from the winter den and molting in late May-early June
Hair samples were taken during bear captures in April–June and reflect the bears’ diet in the previous year; B Posterior distribution of female trophic niche (bold line) and individual dietary niches indicated by each individual’s posterior trophic position (modeled distribution with individual posterior medians indicated by black dots)
Individual specialization accounted for 48% of the phenotypic variation in the trophic position of female brown bears in Central Sweden
We determined the proportion of variance (mean of the posterior distribution) explained by different sources of individual specialization: Offspring social learning from the mother
maternal genotype or maternal environment) explained further similarities in trophic position among daughters of the same mother (and differences between daughters of different mothers)
Densities correspond to the mother’s posterior trophic position with each mother’s posterior medians indicated by black dots
Shadings from light to dark correspond to mothers producing daughters with lower to higher trophic positions
A Trophic position of male (n = 37) and female (n = 49) offspring in the first two years after separation was equally correlated to maternal trophic position suggesting that social learning is not sex-specific
B Offspring trophic position in the first two years after separation was not correlated with the trophic position of their father (n = 17 unique fathers)
Source data are provided as a Source Data file
be caused by individual learning later in life and demonstrates the potential for behavioral innovation in this population
between-individual variation in dietary specialization allows populations to adapt to changes in resource availability
such as new invasive prey or declines in food items due to climate change
We therefore suggest that alternative hypotheses should be evaluated that consider how social learning impacts individual specialization and in turn the adaptability of species under global change
Due to the spatial dependence of these assemblages
it can therefore be difficult to untangle social learning from the mother from other maternal effects (i.e.
maternal genotype or maternal environment)
Our study population spanned over 170 km with spatial proximity explaining 63% of the total phenotypic variation in the trophic position of female bears: individuals further apart tended to have more different diets
when replacing spatial proximity with environmental similarity among home ranges
the explanatory power was attributed to social learning and maternal effects along with the environment
while when omitting the social learning effect
Our results therefore demonstrate that individual dietary specialization is not caused by a single driver in isolation but the product of many factors
Drivers of individual dietary specialization are well documented among populations of the same species
systematic studies delineating the sources of individual specialization within populations are lacking
likely because suitable datasets including multigenerational
social learning and maternal effects can be important sources of dietary specialization
All animal captures and handling were performed in accordance with relevant guidelines and regulations and were approved by the Swedish authorities and ethical committee (Uppsala Djurförsöksetiska Nämnd: C40/3
Samples were collected and stored in Sweden and shipped to Poland and Canada for preparatory procedures and stable isotope analyses
CITES permits were obtained to ship samples (permitting numbers: 16PL000376/WP and 15PL000102/WP)
independent offspring taken in spring at least 10 months after separation from the mother were included in this study
Samples were placed in a paper envelope and dried at ambient temperature
Dried samples were ground with a ball grinder (Retsch model MM-301
We weighed 1 mg of ground hair into pre-combusted tin capsules and combusted them at 1030 °C in a Carlo Erba NA1500 elemental analyzer
N2 and CO2 were separated chromatographically and introduced to an Elementar Isoprime isotope ratio mass spectrometer (Langenselbold
Two reference materials were used to normalize the results to VPDB and AIR for δ13C and δ15N measurement
respectively: BWB III keratin (δ13C = −20.18‰
Measurement precisions as determined from both reference and sample duplicate analyses were ±0.1‰ for both δ13C and δ15N
Under an omnivorous diet including the consumption of herbivores (in particular moose but also ants such as Formica spp., Camponotus herculeanus with average δ15N indistinguishable from moose, Fig. S1)
bear trophic position values were expected to fall between 2 and 3
Values approaching 4 indicate a trophic enrichment through the consumption of other omnivorous or carnivorous animals
Because absolute trophic position values by definition depend on the δ15N of the food source used to calculate them
the values reported in our study should not be used for comparing the degree of carnivory in our study to other study systems and populations
The study was based on a population of marked females and their offspring
all mothers included in this study were known from observations of mother-offspring associations
VM pools the remaining phenotypic variation of offspring trophic position that cannot be explained by maternal trophic position
Since age and time since separation were perfectly correlated (Pearson correlation coefficient >0.99) we accounted for age with a nonlinear effect of time since separation between mother and daughter (second-order polynomial
We further accounted for a decrease in the social learning effect over time by fitting an interaction between maternal trophic position and time since separation
controlling only for bear ID and genetic structure
Keeping the architecture of our pedigree (Dam/Sire pairs) but randomly assigning parents to offspring
fitting 1000 animal models as null distribution
If related individuals have similar dietary specialization (i.e.
the observed pedigree should explain more variance than the permutated pedigrees
We thus generated a p-value by calculating the proportion of permutated models where the explained variance was larger than the explained variance in the observed dataset
To evaluate paternal effects on offspring trophic position we fitted a mixed-effects model with offspring trophic position in the first two years after separation as response and the posterior trophic position of the father (Supplementary Note 2) as predictor
while controlling for repeated measures with a random intercept for bear id
We compared the model to a null model using leave-one-out-cross-validation (loo)
determined the variance explained by the paternal trophic position
and computed the Pearson correlation coefficient between the paternal and offspring trophic position
Further information on research design is available in the Nature Portfolio Reporting Summary linked to this article
Code to reproduce all analyses are provided in the OSF repository; under the accession code https://doi.org/10.17605/OSF.IO/68B9U78
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Milk bottles revisited: social learning and individual variation in the blue tit
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Kilda Soay sheep (Ovis aries) results in little change in heritability estimates
ctmm: an r package for analyzing animal relocation data as a continuous-time stochastic process
Landscapemetrics: an open-source R tool to calculate landscape metrics
Revising how the computer program cervus accommodates genotyping error increases success in paternity assignment
COLONY: a program for parentage and sibship inference from multilocus genotype data
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partR2: partitioning R2 in generalized linear mixed models
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comparison and testing of statistical models
brms: an R package for Bayesian multilevel models using Stan
Stan: a probabilistic programming language
and localization: An improved R̂ for assessing convergence of MCMC
R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing
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has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie Grant agreement No 793077 and from the German Science Foundation (HE 8857/1-1)
The study was further funded by the Norway Grants under the Polish-Norwegian Research Programme administered by the National Research Centre for Research and Development in Poland and the Norwegian Research Council (J.A.
and A.Z.; GLOBE No POL-NOR/198352/85/2013)
Isotope analyses were funded through a Robert Bosch Foundation grant to TM and the GLOBE project and conducted by KAH (with assistance from Blanca Xiomara Mora Alvarez and Geoff Koehler)
We thank the Scandinavian Brown Bear Research Project (SBBRP) for providing access to the data
The SBBRP was funded by the Norwegian Environment Agency
the Swedish Environmental Protection Agency
Open Access funding enabled and organized by Projekt DEAL
Senckenberg Biodiversity and Climate Research Centre (SBiK-F)
Consejo Superior de Investigaciones Científicas
Department of Biology and Advanced Facility for Avian Research (AFAR)
Department of Veterinary Biomedical Sciences
Swedish University of Agricultural Sciences
Department of Natural Sciences and Environmental Health
Institute of Wildlife Biology and Game Management
University of Natural Resources and Life Sciences
managed the hair samples database and prepared samples for stable isotope analyses by K.A.H
provided laboratory space and resources and supervised preparatory procedures
constructed and provided the genetic pedigree
advised to the analysis and interpretation of stable isotope data
performed the statistical analyses with input from J.A
The authors declare no competing interests
Nature Communications thanks the anonymous reviewers for their contribution to the peer review of this work
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations
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DOI: https://doi.org/10.1038/s41467-024-54722-z
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Volume 12 - 2024 | https://doi.org/10.3389/fevo.2024.1504225
Epigenetic mechanisms such as methylation can influence gene expression and play a crucial role in the adaptation to local environmental conditions
thereby introducing non-genetic variability within species
using a Reduced Representation Bisulfite Sequencing approach (RRBS)
we compared the methylation patterns in blood and muscle across three European brown bear populations
the methylation patterns of the three populations are significantly distinct
possibly associated with genomic features involved in development and anatomical differentiation
This finding supports previous studies suggesting a role for the alteration of developmental pathways in shaping phenotypic novelties with potential adaptative significance
Our results underscore the importance and the effectiveness of including epigenetic approaches in studying wild non-model organisms
Investigating the epigenome can be especially relevant for endangered populations that have experienced a significant erosion of genomic diversity
The evolutionary trajectory of a species is primarily driven by its genetic diversity. Nevertheless, an increasing body of evidence emphasizes the significant contribution of epigenetic diversity to species evolutionary potential (Baltazar-Soares et al., 2024). Despite the significant implications of epigenetic pattern variations, this aspect at the population level in non-model species remains largely unexplored (Vogt, 2022)
thereby enhancing our understanding of the intricate interplay between genetic and epigenetic factors in the context of evolutionary processes
examining methylation patterns in blood could also provide valuable insights into the immune adaptations of wild populations
that in turn could reflect differences at physiological and metabolic level
the three bear populations included in this study are good candidate to gain initial insights into the role of epigenomic differentiation as a potential source of phenotypic divergence and plasticity
The DNA from blood was extracted using a Blood DNA Isolation Mini Kit (Norgen Biotek Corp)
whereas DNA from muscle was extracted using a Quick-DNA miniprep Kit (Zymo Research) following companies’ guidelines
Library preparation and sequencing were performed by Genomix4life S.R.L
Input DNA concentration of each sample was assayed with a Qubit fluorimeter (Life Technologies)
and its quality assessed with a TapeStation 4200 (Agilent)
Indexed libraries were constructed from 100 ng of purified DNA with an Ovation RRBS Methyl-Seq System according to the manufacturer’s instructions
The current approach utilizes the methylation insensitive restriction enzyme MspI
whose quality and quantity were assessed with a TapeStation 4200 and Qubit fluorometer
The pooled samples were paired-end (2x101bp) sequenced on a Novaseq6000 (Illumina)
The 12 methylome raw files were deposited into the NCBI SRA database under the Bioproject PRJNA1104803
Filtered fastq files were processed using the software Bismark v0.24.1 (Krueger and Andrews, 2011)
Initially the fastq files were aligned to the brown bear Ursus arctos genome assembly (UrsArc2.0; NCBI RefSeq code: GCF_023065955.2) using Bowtie2 with parameter –score_min L,0,-0.6
Then the methylation call was performed using default Bismark parameters
The obtained cytosine coverage files were used to investigate methylation profiles and perform a differential methylation analysis at regional level using the R package methylKit v1.28 (Akalin et al., 2012)
We discarded sites with less than 10X and 99.9% of coverage
Then we performed a normalization of the coverage values among samples using a scaling factor derived from differences between median of coverage distributions as implemented in methylKit
we excluded those CpG sites that have no or little variation among study subjects and are not particularly informative for downstream analyses retaining only those sites with a standard deviation larger than two
Due to X chromosome dosage compensation between females and males (Cecalev et al., 2024)
we filtered out sex chromosomes from the analysis to reduce a potential bias on the inference at a population level
because X chromosome may still bring information on differentiation between populations
the methylation pattern in X chromosome was also investigated separately
sex-filtered (autosomes only) and X chromosome datasets were used to explore the pattern of differentiation between populations and tissues estimating the Pearson correlation coefficient among individuals and performing a Principal Component Analysis (PCA)
Successively we identified Differentially Methylated Regions (DMRs) in autosomes between populations for the muscle (Apennine vs Scandinavia) and for the blood (Apennine vs Alpine)
For DMR analysis the filtering was performed as for site level methylation but retaining sites with at least 3X coverage
Then the DMRs were identified with a non-overlapping sliding window of 1000 bp and retaining DMRs with at least 10 methylated bases
Differential methylation between Apennine and Alpine bears (for blood) and between Apennine and Scandinavian bears (for muscle) was tested using Chi-square test with overdispersion correction (McCullagh & Nelder method) and P-value adjusted using a Sliding Linear Model (SLIM)
DMRs were retained when we found at least 25% methylation difference and a q-value <0.01
Heatmap of Pearson correlation coefficients (r) for autosomes and the X chromosome
Cluster dendrograms illustrate similarities based on correlation values
we observe low correlation between different tissue types but high correlation within samples of the same tissue type
Distinct “correlation clusters,” reflecting population membership
are particularly prominent in blood samples (highlighted in red)
the X chromosome displays high correlation not only within the same tissue type but also across different tissues from individuals within the same population
Principal Component Analysis (PCA) of autosomal methylation frequencies further reveals a clear structure in the epigenetic profiles of the 12 samples
grouping them by tissue type and population into four distinct clusters consistent with the correlation analysis
PCA of X chromosome methylation frequencies continues to differentiate these four groups effectively
The PCAs for both autosomes and X chromosome agree with the estimated correlation level showing a clear pattern of differentiation between tissues and populations for autosomes, less pronounced for X chromosome (Figure 1). Population differentiation is maintained in PCAs performed separately for each tissue (Supplementary Figure S3)
PC1 is associated with population differences
whereas PC2 seems not directly linked with known variables
Methylated cytosines were grouped in 639 different methylated regions (DMRs) in blood and 186 DMRs in muscle samples (Figure 2)
Volcano plots show differential methylation at regional level (DMR) in two pairwise comparisons between populations for blood and muscle (left and right respectively)
Red points indicate DMRs with significant q-value < 0.05 and effect size larger than ±25%
According to the distances from the nearest transcription start site (TSS), a larger fraction of DMRs is located within intergenic and intronic regions, distal from the TSSs, whereas promoters are a lower fraction, less than 10% (Figure 3)
Histogram representing the distance of DMRs from the TSS suggests that in blood (left) and muscle (right) the DMRs are mostly found across intergenic and intronic regions
Based on the nearest TSS, we linked DMRs to 416 and 115 annotated genes in blood and muscle respectively. According to the Gene Ontology (GO) enrichment analysis, the higher number of enriched GO terms was found in blood samples compared to muscle, with 20 and 3 GO terms respectively (Supplementary Table S2)
In both the tissues most of the GO terms are related to morphogenesis and development at organismal and cellular levels
our analysis underscores methylation profiles associated with population structure
This pattern may reflect shared ancestry of X chromosomes among individuals within populations; however
further investigation with a larger dataset is warranted to substantiate these findings
identifying sites shared between the two tissues and associated with major pathways relevant to bone regulation
This suggests that peripheral blood may serve as a viable proxy tissue for large scale genome-wide methylation study in living animals
an inspection of DMRs close to promoter regions (approximately +/- 2000 bp from TSS) highlight the possible regulative role on genes such Colony Stimulating Factor 3 (CSF3)
Class II Major Histocompatibility Complex Transactivator (CIITA)
we found evidence of a close association of DMRs to genes directly involved in developmental processes such as Bone Morphogenetic Protein 7 (BMP7) and Homeobox B3 (HOXB3) and genes involved in metabolic pathways such as Galanin Receptor 3 (GALR3)
Arachidonate 15-Lipoxygenase (ALOX15) and LDL receptor related protein 5
highlighted the occurrence of several putative deleterious mutations associated with human disorders such as craniofacial and ocular anomalies
that could partially explain the phenotypic divergence of the Apennine brown bear
aimed at safeguarding the adaptive and evolutionary potential of the species
The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: https://www.ncbi.nlm.nih.gov/
The study was conducted in accordance with the local legislation and institutional requirements
LGe: Writing – review & editing
The author(s) declare financial support was received for the research
This project was founded by PRIN (Progetti di Rilevante Interesse Nazionale) 2022PYJWJA “Epigenetics and conservation of small populations: microevolution and adaptive divergence in relict bear populations” CUP: B53D23012260006
ES and PCo were also funded by the National Recovery and Resilience Plan (NRRP)
Mission 4 Component 2 Investment 1.4 - Call for tender No
rectified by Decree n.3175 of 18 December 2021 of Italian Ministry of University and Research funded by the European Union – NextGenerationEU; Project code CN_00000033
1034 of 17 June 2022 adopted by the Italian Ministry of University and Research
CUP B83C22002930006 Project title “National Biodiversity Future Center - NBFC”
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest
The author(s) declared that they were an editorial board member of Frontiers
This had no impact on the peer review process and the final decision
The author(s) declare that no Generative AI was used in the creation of this manuscript
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations
Any product that may be evaluated in this article
or claim that may be made by its manufacturer
is not guaranteed or endorsed by the publisher
The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fevo.2024.1504225/full#supplementary-material
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Received: 30 September 2024; Accepted: 23 December 2024;Published: 24 January 2025
Copyright © 2025 Colangelo, Bonapace, Gramolini, Solano, Desiato, Franchini, Gentile, Guadagnini, Kleven, Kindberg, Kopatz and Ciucci. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
distribution or reproduction in other forums is permitted
provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited
in accordance with accepted academic practice
distribution or reproduction is permitted which does not comply with these terms
*Correspondence: Laura Gramolini, bGF1cmEuZ3JhbW9saW5pQGlyZXQuY25yLml0
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2025 ✅ Big Air Finals at Ursus Snowpark ✅ Giro Dual challenge ✅ Closing Party @ Fortini LAB
this competition is a direct qualifier for the 2026 World Rookie Finals
The top 3 Rookie and Grom riders (men & women) in both snowboard and freeski will secure their spot for the finals
setting the stage for their path to international recognition
💰 Entry fee: €60 💰 Entry fee + 3-day lift pass: €199
🏨 All-inclusive accommodation packages:🔹 Madonna di Campiglio (5 min from gondola): €390 (riders) / €444 (adults)
🏆 World Rookie Camp riders get their Ursus Big Air entry fee included in their package
To register, riders must pre-register via email (info@blackyeti.info)
and each application must be reviewed and approved by the race and event directors
Located in one of Europe’s most iconic freestyle hubs
Ursus Snowpark in Madonna di Campiglio offers world-class facilities
and an atmosphere that guarantees an unforgettable end-of-season experience
Whether you’re aiming for the podium or to witness some of the best Big Air action
this event is a must for all snowboard and freeski fans
The Ursus Big Air 2025 is set to be a thrilling competition in one of Europe’s top freestyle destinations
Whether you’re a rider pushing for the World Rookie Finals or a fan looking to witness next-level Big Air action
📍 Where: Ursus Snowpark, Madonna di Campiglio 📅 When: April 18-20, 2025 🎟 Registration form & info sheet
Few things are more thrilling than sitting 15 feet from a large brown bear fishing in the wild
close encounters would be delightfully commonplace
My trip included more time in the field and an expert bear guide-photographer
positioning and technique for capturing meaningful wildlife imagery
The eight-day expedition kicked off in Kodiak
where we explored the island’s waterways by private boat
puffins and a raft of sea otters nearly 200 strong
A 45-minute floatplane flight set us down in Katmai National Park and Preserve the following morning
The park’s jaw-dropping landscapes can only be accessed by air or water and are home to one of Alaska's highest densities of coastal brown bears
has spent years in this region observing the animals with small groups
Ursus — a converted
73-foot former crabbing vessel with four guest cabins sharing two full bathrooms — served as our home base
(Reality show fans will remember it as the Time Bandit from the hit show “Deadliest Catch.”) Where and when we sailed was dictated by Alaska’s ever-changing weather
which occur in bays and tributaries at different times
but anchored in the stunningly beautiful Geographic Harbor
where calmer waters prevailed and photo opportunities were high
The ship's skiff ferried us to various spots along the coast twice daily
we hiked to sandbars with clear views of the bears fishing
Eggleston placed us at least 150 feet from the bears
the charismatic predators often meandered around us
giving us front-row seats to their fishing
a bear came within 8 feet us — we dubbed these moments “drive-bys.” Several times
the animals fished within 15 to 20 feet of our group
You won’t find luxury accommodations on the Ursus
Each room features two twin berths and an en-suite sink
wood-paneled galley with a large horseshoe-shaped banquet where we dined
chatted and spent one stormy morning watching a National Geographic documentary
where tourists are scarce and the animals are accustomed to humans
Having been on several safaris and other wildlife adventures
this was one of the most intimate and exceptional
For clients who want to see mating behaviors
June through the beginning of July is the best time to book
travelers should be in good shape and be able to navigate uneven terrain
sit for long periods and be comfortable with a “wilderness toilet.”
which often delays or cancels flights (especially the regional floatplanes)
I recommend travel advisors book an extra night on either side of the trip’s start and end dates
Kodiak has plenty of activities to keep folks occupied
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Paleontologists have discovered a set of ancient bear footprints in Honseca Cave
Although distinguishing cave bear from brown bear tracks is complex
cave bears are considered the most likely tracemakers in Honseca
Cave bears (Ursus spelaeus) were a very large type of bear that formed the sister lineage of living brown bears and polar bears
These animals lived in Europe and Asia during the Pleistocene epoch and became extinct about 24,000 years ago
They were 2.7-3.5 m (8.9-11.5 feet) long and up to 1.7 m (5.6 feet) at the shoulder
Cave bears and people likely encountered one another occasionally
they didn’t actually live in caves but only used them for hibernation
The massive grinding molars and nitrogen-isotope data from its bones indicate that cave bears were primarily herbivorous
“Cave bear tracks are not uncommon in the soft sediments of the caves of the Iberian Peninsula and many speleologists are familiar with their presence,” said Dr
Ana Mateos from the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH)
until now these fossil traces had not been the subject of systematic research.”
to date only one study of this type was carried out in Urşilor Cave in Romania.”
Reconstruction of the cave bear (Ursus spelaeus)
Image credit: Sergio de la Larosa / CC BY-SA 3.0
Mateos and colleagues discovered a set of 16 cave bear footprints in Honseca Cave
The footprints were assigned to Ursichnus europaeus and represent the first record of this ichnospecies from a cave in the Iberian Peninsula
“We carried out a scan of the surface with the footprints and its immediate surroundings with a laser scanner that creates a three-dimensional cloud of millions of points and we combined it with a model obtained by photogrammetry,” said Dr
“This model has been used to take different measurements of the footprints and compare them with those of other caves in Europe
processing the model has allowed us to generate images that highlight the shape of each individual footprint,” added Dr
“The shape of the toe impressions and the length of the claw marks
suggest that in both cases they belong to cave bears
a species that went extinct around 28,000 years ago
some of the footprints were destroyed by the footsteps of amateurs who visited the interior of the cave without being careful before the scientists knew of their existence,” said CENIEH’s Dr
one of the goals of these types of studies is to highlight the value of these fossils and promote their preservation.”
The study was published this month in the journal Ichnos.
J. Rodríguez et al. Cave bear tracks (Ursichnus europaeus Diedrich, 2011) from Honseca Cave, Palencia, Spain. Ichnos, published online January 9, 2025; doi: 10.1080/10420940.2024.2446153
Volume 6 - 2025 | https://doi.org/10.3389/fcosc.2025.1470223
A correction has been applied to this article in:
Corrigendum: Identifying corridors for Asiatic black bear (Ursus thibetanus) in a part of Eastern Himalayas
classified as a vulnerable species on the IUCN Red List
is an important mammal species found in the state of Sikkim
Studies carried out in Khangchendzonga National Park have documented the presence of these bears
highlighting their crucial conservation importance in the region
The population of Black bears are restricted to small habitat patches
which over the years have become fragmented by road networks and urban settlements
connecting corridors play a crucial role in maintaining wildlife movement and genetic diversity
We assessed connectivity between eight protected areas in Sikkim using MaxENT and Circuitscape
65 black bear presence locations (collected through Camera traps and sign surveys) and 24 environmental variables were used to model the corridors
Habitat suitability map was generated through MaxENT modelling approach
Our analysis suggests that there are multiple options to maintain connectivity for black bears in Sikkim
We mapped seven corridors and five pinch points (bottlenecks in connectivity)
and calculated metrics to estimate their quality and importance
Our model output was supported by high AUC value (0.921) and field validation by questionnaire surveys and sign surveys to assess black bear presence and habitat use
Our results showed that 300 km² of the suitable regions are within the protected areas in Sikkim
The highest quality linkages as measured by the ratio of cost-weighted distance to Euclidean distance (CWD:EucD) and cost-weighted distance to least-cost path (CWD:LCP) were Khangchendzonga and Barsey
suggesting that these protected areas (National Parks and Wildlife Sanctuaries) and the developed corridors play important role in maintaining connectivity
We mapped pinch-points which are habitat where black bear movement is restricted due to unfavorable environments
built up/settlements or a combination of factors and our model predicted pinch points near few settlement areas; Mangan
Ground truthing confirmed that these areas also coincide with Black bear conflict zones in Sikkim
Study area map showing the occurrence points used for modelling
Black bears in Himalaya rely on Climatic information to use the habitat connectivity as they inhabit a wide range of elevations
from subtropical forests to alpine regions
and seasonal variability greatly influence habitat availability and food resources
Climatic factors such as temperature and moisture levels directly affect vegetation types and abundance
which are critical for the bear’s diet and shelter
Black bears exhibit seasonal migrations in response to climate-driven changes in food availability
bears often move to lower altitudes during winter months to escape harsh climatic conditions
These seasonal shifts highlight the importance of climate in determining the timing and routes of their movements
climate plays a significant role in determining the bear’s movement patterns and habitat use
the objectives of this study were: 1) to delineate connectivity corridors for Asiatic black bears in Sikkim
identifying areas that ensure long-term connectivity between protected areas
and 2) to identify pinch points where human-black bear interactions are more frequent
The research aimed to address two key questions: (1) What are the critical habitat corridors that facilitate connectivity between protected areas for Asiatic black bears in Sikkim
and (2) Which areas in Sikkim experience the highest frequency of human-black bear conflicts
The underlying hypothesis is that Asiatic black bears use specific natural corridors
and that these corridors are disrupted by human activities like deforestation and infrastructure development
The state’s forest cover includes subtropical forests
which are characterized by a mix of broadleaf species
temperate forests dominate between 1500m and 3500m
are sparse and adapted to harsh conditions
providing crucial seasonal foraging grounds for species such as the black bear during summer months
These habitat types are vital for maintaining the ecological corridors that allow species to migrate between seasonal ranges
Details of eight protected areas in Sikkim
Moreover, human settlements and infrastructure, present significant challenges for corridor connectivity (Chanchani et al., 2010; Das et al., 2013)
which connects Sikkim to the rest of India
and other smaller roads through forested areas
create barriers to wildlife movement and increase the likelihood of roadkill
The planned expansion of such infrastructure in the state
threatens to further fragment wildlife corridors unless mitigated by wildlife-friendly design solutions
The primary livelihoods of the local population are majorly tourism, agriculture, and livestock rearing. The Lepcha, Bhutia, and Nepalese communities rely on the forests for various resources such as fuelwood, ferns, timber, medicinal plants, and fodder (Basnett et al., 2020)
This study used MaxENT (through kuenm package), and Circuitscape software to map corridor connectivity and bottlenecks among eight protected areas (PAs) for black bears in Sikkim. Circuitscape applies circuit theory, modeling the landscape as a continuous resistance surface where movement mimics current flow. Low-resistance areas facilitate movement (e.g., suitable habitats), while high-resistance areas hinder it (e.g., urban areas or barriers) (Dickson et al., 2019)
While a large portion of Sikkim offers suitable habitats for black bears
the PAs were selected as nodes for the species due to their suitability as habitats and the legal protection they offer to the species and its habitat
Field surveys and interaction with local communities across Sikkim helped gather data on black bear presence and conflict. Using 65 black bear occurrence points and 24 environmental and bioclimatic variables, a habitat permeability layer was generated in R studio with the kuenm package (Cobos et al., 2019)
The Habitat permeability layer highlights the ease of species movement through the landscape
focusing on habitat features influencing dispersal
unlike species distribution maps that show geographic range
The permeability layer was then used as an input in Circuitscape and Linkagemapper in ArcGIS software to model corridors and delineate pinch points among the eight PAs in Sikkim
Ground surveys were conducted to validate the quality of these corridors and pinch points
while also identifying potential causes of conflict
We have used the ‘Kuenm’ package in R version 3.6.3 to calibrate, evaluate and build the habitat permeability layer for black bears in the Sikkim landscape. Figure 2 shows the methodological flowchart followed during modelling
Flow chart of the research methodology used in this study
we generated a spatial bias surface using background sampling that reflects the sampling effort and accessibility across the study area
This bias surface is derived from the density of presence records and corrected for areas with over-representation
ensuring that spatial bias does not unduly influence the predictions
A total of 65 species occurrence points (represented in Figure 1) are used to model a habitat permeability layer
The presence points were split into training (70%) and testing (30%) for building the model using random splitting to ensure that the training and test datasets were representative of the overall distribution of presence points across the study area
Contribution of environmental variables in MaxENT model
The best model was statistically significant with low omission rates and low Akaike information criterion (AICc)
We evaluated the results of the MaxENT model using the AUC value (Area under Receiver Operating Characteristic Curve)
A high AUC value reflects that the model prediction is non-random and can accurately map locations where the species is present or absent
The final output was then converted to a friction layer using the SDM toolbox in ArcGIS and used as a resistance surface for Circuitscape
We calculated two metrics to evaluate the quality of each linkage
The first metric is the ratio of cost-weighted distance (CWD) and the Euclidean distance (EucD) between each pair of PAs
the cost-weighted distance equals the Euclidean distance
This ratio reflects the difficulty of moving between PAs relative to their proximity
The second metric is the ratio of the cost-weighted distance to the length of the least-cost path (CWD: LCP)
indicating the average resistance encountered along the optimal path between the PAs
Once corridors were mapped, we used the ‘Pinchpoint Mapper’ tool in Linkagemapper 2.0 to map the pinch points or corridor bottlenecks where movement would be funneled, and thus, it may be essential to keep them intact. Even a slight area loss in these pinch points would disproportionately compromise connectivity (Castilho et al., 2015)
We used a cut-off width of 1 km to create the Pinch points
Jackknife tests of variable importance were used to identify those with significant individual effects. Major contributing variables of the model were Bio12-Annual precipitation (19.2%), Bio07- Annual temperature range (14.4%), and slope (11.7%). The contribution of the remaining 21 variables was <10% each (Table 2). The Jackknife test results and response curve of the final models are given in (Supplementary Figures 3, 4)
The values are averages over 10 replicate runs
Suitable areas for the species within and around the protected areas boundaries in Sikkim
This study provides the first account of the potential connectivity corridors and pinch points between different PAs for black bears within Sikkim. We have delineated eight corridors across PAs through different landscapes. The corridors (Figure 4) between Singba Rhododendron Sanctuary and Khangchendzonga NP; Fambong Lho WLS and Kyongnosla Alpine Sanctuary; and Khangchendzonga NP
and Maenam WLS have the potentially high current flow based on the model
indicating critical pathways for movement of the species
Delineated corridors between 8 protected areas in Sikkim
The model exhibited the presence of pinch points between each pair of PAs (focal nodes), illustrating crucial areas for keeping the habitat connected. We identified fifteen pinch points in the corridors we mapped (Figure 5)
Analyzing the corridors between individual pairs of PAs highlights areas with the highest pairwise current flow
indicating constricted movement pathways between two PAs
Delineated pinch points across 8 protected areas in Sikkim
Fifteen linkages were identified (Table 3) and the pinch points within reserve forest areas receive protection from the forest department
Characteristics of the 15 mapped linkages between the 8 protected areas in Sikkim
These concepts are essential in corridor analysis
helping to determine optimal connectivity by balancing spatial distance
and resistance values to establish effective pathways for wildlife and ecosystems
The linkages metric varied between different pairs of PAs. The ratio of CWD: EucD is the lowest (3.74) (Table 3) between Khangchendzonga NP and Barsey Rhododendron WLS
indicating the highest quality along the shortest path for this pair
This ratio is highest (11.35) for Kyongnosla Alpine Sanctuary and Pangalokha WLS
meaning movement is difficult between different PAs after accounting for Euclidean distance
although Kyongnosla-Pangalokha and Fambonglho-Maenam are similar in terms of Euclidean distance (6.75 and 6.56 respectively)
the cost of moving between the former is much higher than the latter (CWD: EucD ratio 11.35 and 7.97
The ratio of CWD: LCP is the lowest between Khangchendzonga NP and Barsey Rhododendron WLS (CWD: LCP = 3.3) indicating low resistance to movement along the path of lowest resistance
and it is highest between Kyongnosla and Pangalokha (CWD: LCP = 10.37)
indicating high resistance along the path of least resistance
Three delineated corridors (i.e., 1. Kyongnosla WLS- Pangolakha WLS; 2. Khangchendzonga NP and Kyongnosla WLS; 3. Maenam WLS and Khangchendzonga NP) fall within reserve forests and have legal protection. The remaining corridors and pinch points (Figures 4, 5) are outside PAs and reserve forests mentioned below
Fambhonglho WLS and Khangchendzonga NP (Figures 4, 5A): Our model identified Pinchpoint near two significant human habitats
Ground surveys in the two areas confirmed indirect black bear sightings and incidents of human-black bear interface
The number of bear attacks is also high in Singtam
Fambong Lho WLS – Kyongnosla Alpine WLS (Figures 4, 5B): This corridor is close to the state capital
and road networks potentially threaten this corridor
The pinchpoint in this corridor is near Pangthang and Kabi
Locals of the area confirmed black bear interface incidents
Another Pinchpoint is modelled near Golitar (Near Gangtok)
we found direct and indirect evidence of black bear and conflict incidents (with humans and livestock) in the Golitar area
Khangchendzonga NP and Barsey Rhododendron WLS (Figures 4, 5C): This corridor is in West Sikkim and is close to Yuksum and Pelling
The model corridor pinch point is near Yuksum
We found major human-animal interface incidents reported near the southern buffer range of Khangchendzonga NP
The corridors and pinch points are adjacent to Gerethang reserve forests in west Sikkim
High human-bear interface incidences are reported near Meli
Tourism pressure is a significant threat to this corridor
particularly in areas near Geyzing and Pelling
Khangchendzonga NP and Shingba WLS (Figure 4A): This corridor lies in the North Sikkim near Chungthang and Lachung
connecting Singhba with Eastern parts of Khangchendzonga NP
Locals of Lachung and Chungthang reported interface incidents that happened mainly near maize fields
Maximum number of bear attacks were reported in Lachung
especially the corridors and pinch points beyond PAs and reserve forests
need to be extensively surveyed to develop a strategic conservation plan to ensure the species’ dispersal and survivability and minimize the human-black bear conflict
a study on the movement ecology of black bears using satellite telemetry is required to understand the functionality of these modelled corridors
identify the spatial and habitat requirements
and detect the hibernation pattern of the species
The survival of Asiatic black bear is linked to their ability to move across landscapes that extend beyond protected areas (PAs)
highlighting the importance of connectivity corridors for facilitating movement
threaten these corridors and increase human-wildlife conflicts
particularly between black bears and local communities
Our study identifies critical corridors and pinch points
many of which are outside PAs and reserved forests
emphasizing the need for strategic conservation planning in these areas
Ground surveys and local reports confirm the high frequency of human-black bear conflicts
underlining the urgency of incorporating community-based conservation efforts
Protection of corridors for a large mammal will aid in dispersing other flora and fauna
There are multiple incidents of Human-bear conflict (i.e.
especially in the bottleneck corridors identified in this study
scat analysis (for population estimation as well as diet study)
interaction with local people for prevention and management of the conflicts) in these bottleneck areas to create habitat management plans to ensure safe dispersal of the species among different PAs
Black bear food plants could be planted in a planned way outside the PA boundaries and along the corridors to reduce human-bear interface to ensure possible movement of black bears inside and outside the PAs
Use of traditional and modern crop protection measures
and sensitization workshops for the locals to be accorded high priority
Informing the potential conflict locations
ways to improve habitats outside PA and available solutions that are essential strategies in the overall restoration effort
Further studies can be carried out to check the transboundary connectivity through satellite telemetry and corridor modelling
As Sikkim shares international boundaries with Bhutan
transboundary landscape connectivity will enable genetic dispersal across geopolitical boundaries and maintain Asiatic black bears’ continuous movement in the event of habitat shift or expansion owing to future climate change
The integration of ecological corridors into conservation planning
coupled with efforts to mitigate human-wildlife conflicts
will be crucial for ensuring the long-term survival of black bears in the region
The original contributions presented in the study are included in the article/Supplementary Material
Further inquiries can be directed to the corresponding author
Ethical approval was not required for the study involving animals in accordance with the local legislation and institutional requirements because this research work focuses solely on spatial mapping and ground validation of connectivity between different PAs for Black bears and does not involve any clinical research on animals or any form of medical research on humans
Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements
Written informed consent from the participants was not required to participate in this study in accordance with the national legislation and the institutional requirements
The author(s) declare that financial support was received for the research
This study was supported by the funding agency United Nations Development Programme (UNDP) and Swiss Agency for Development and Cooperation (SDC)
The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fcosc.2025.1470223/full#supplementary-material
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Received: 25 July 2024; Accepted: 13 January 2025;Published: 03 February 2025
Copyright © 2025 Bhattacharya, Sarkar, Pandey, Mondal, Sathyakumar, Kumar and Talukdar. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
*Correspondence: Gautam Talukdar, Z2F1dGFtQHdpaS5nb3YuaW4=
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(Read E.O. Wilson’s Britannica essay on mass extinction.)
Extinction of the cave bear seems to have been a gradual process that was complete between 28,000 and 27,000 years ago
It has no natural predators and knows no fear of humans
Polar bears are mostly carnivorous. They eat the ringed seal as well as the bearded seal and other pinnipeds
polar bears are opportunistic as well as predatory: they will consume dead fish and carcasses of stranded whales and eat garbage near human settlements
One important adaptation of polar bears to their unique climate is the transparency of their thick fur, which allows sunlight to pass through and reach their black skin, where heat from the sun is then absorbed. Another adaptation is polar bears’ use of only their front limbs when swimming, which is found in no other four-legged mammal
as does the uneven skin on the soles of the feet
sharp claws are also important for gaining traction
are born during the winter in a den of ice or snow
Cubs weigh less than 1 kg at birth and are not weaned until after they are two years old
Young polar bears may die of starvation or may be killed by adult males
and for this reason female polar bears are extremely defensive of their young when adult males are present
Young remain with their mothers until they reach sexual maturity
Females first reproduce at four to eight years of age and breed every two to four years thereafter
Males mature at about the same age as females but do not breed until a few years later
Adult polar bears have no natural predators
but in captivity several polar bears have lived to more than 35 years old
Volume 12 - 2024 | https://doi.org/10.3389/fevo.2024.1477480
The main cause of the global threat to large carnivore populations living in high-altitude areas is human pressure
The Himalayan brown bear (Ursus arctos isabellinus
hereafter bear) is listed as a critically endangered species
and it dominates the higher altitudes of the North and Western Himalayan landscapes
we used species distribution modelling and landscape connectivity to find bears’ suitable habitats and corridors in the Deosai National Park (DNP) and surrounding areas
Species distribution models detected a bear’s suitable habitat of 1,125 km2
The most crucial predictors in determining the bears’ distribution were elevation—particularly if it was between 3,500 and 4,500 meters above sea level—as well as the bears’ distance from rivers
We discovered robust connectivity among presence points in the core of the study area
by using the electrical circuit theory models
Landscape connectivity values were indeed low in some areas outside and close to the DNP confines
it is imperative to protect habitats and corridors that allow the bears to migrate between the suitable patches
particularly beyond the park’s boundaries
These assessments consider the species’ geographic location and their critical function in promoting migration within the available habitat
Our study used a mix of Species Distribution Models (SDMs) and corridor network simulators to determine the habitat suitability and landscape connectivity for bears in DNP
we also explored the role and importance of the single variable in identifying the most important areas for bear distribution in DNP and neighbouring areas
We were not confined to evaluating simply the DNP region since we understand that the long-term viability of the Deosai and surrounding bear populations requires landscape-wide management techniques
Because some individuals appear to have home ranges larger than the park
the national park may not be sufficient to ensure long-term population survival
The DNP (75°27′E, 35°00′N) is a 3,584 km2 alpine plateau east of Nanga Parbat Peak, Northern Areas, Pakistan. Elevations range from 3,500 to 5,200 m above sea level, with about 60% of the area between 4,000 and 4,500 m above sea level (Nawaz et al., 2008; Figure 1)
Study area showing the Desoai National Park (black line) and Himalayan brown bear occurrences obtained from the camera traps (green circle)
The vegetation in DNP is primarily herbaceous perennials, with a high number of cushion-forming and tufted species. Grasslands and areas with persistent snow or ice cover make up the majority of the land cover in high-elevation regions. Instead, the valley are mainly constituted by bogs and ponds with associated vegetation such as sedges, grasses, and plants like Aconitum violaceum, Swertia perfoliata, and Saxifraga hircus (Bellemain et al., 2007)
Aside from the issues of overgrazing and soil degradation that affect DNP and its surrounding areas
the most pressing concern is the regions with water bodies and wetlands that are nourished by glacier/snow and permafrost melting throughout the summer
are critical for flora and animals to live and thrive
We used the Variance Inflation Factor (VIF) to evaluate environmental predictor multicollinearity. VIF > 3 was set as the threshold (Zuur et al., 2010), and variables exceeding the threshold were excluded using the USDM package (Naimi et al., 2014) in R. 6.0 (R Core Team, 2019). All the predictors used in our modelling analysis were included in the Table 1
Environmental variables used for species distribution modelling of the Himalayan brown bear in the Deosai National Park and neighbouring areas
We combined five algorithms into two main categories
such as: 1) the regression-based models—Generalized Linear Model (GLM) and Multivariate Adaptive Regression Splines (MARS); 2) the machine learning models—Maximum Entropy Model (MaxEnt)
Patches overlapping with the main presence records were assumed to be the core of the bear’s habitat suitability
and the total coverage by DNP was calculated
We carried out electrical circuit modelling using Circuitscape v4 (McRae and Shah, 2009) through an all-to-one approach that maps current density occurrences, consuming less RAM (McRae et al., 2008)
The resistance map and bear occurrence records were used as inputs
We determined connections to eight neighbours per cell
Lower resistance indicates a higher movement density
We found that five models (GLM, MaxEnt, RF, MARS, and GBM) showed high model validation values with AUC > 0.9 and TSS > 0.75, respectively. RF obtained the best performance (Table 2). We detected that elevation and distance from DNP, livestock, and rivers were the most important variables for predicting the potential distribution of bears (Table 3)
Values of Area Under Curve (AUC) and True Skill Statistics (TSS) of the five algorithms used in the ensemble model approach for the Himalayan brown bear in the Deosai National Park and neighbouring areas
Percentage of variable contributions (mean and standard deviation SD) included in the species distribution modelling for the Himalayan brown bear in the Deosai National Park and neighbouring areas
Low habitat suitability values increased with distance from DNP borders (up to ~10 km). The bear’s probability of presence was consistent about 2 km from rivers. Up to around 20 kilometers from roadways, bear habitat suitability appeared to improve. Distance from livestock regions decreased gradually, unlike distance from livestock transportation routes, which decreased quickly before flattening at around 20 km (Figure 2)
high probabilities of bear presences were found between 3,750 and 4,250 meters above sea level
Response curves (from 0 to 1) of the environmental predictors used in species distribution modelling for the Himalayan brown bear in the Desoai National Park
According to the ensemble suitability maps, the bear’s habitat suitability was highest in the central region of the research area (inside DNP), while there were also other suitable patches in nearby areas (Figure 3). These locations are crucial for encouraging bear migration over their whole range (Figure 3)
Potential distribution of the Himalayan brown bear in the Deosai National Park and neighbouring areas
Habitat patches for the Himalayan brown bear in the Deosai National Park and neighbouring areas
Landscape connectivity map for the Himalayan brown bear in the Deosai National Park and neighbouring areas
We explored the current distribution and landscape connectivity of the bear in the DNP and surrounding areas to shed light on the factors that are needed for its presence and conservation
Our spatial analysis findings confirmed that the Himalayan and Karakorum-Pamir highlands are the center of the ecosystem where the most important bear populations in Pakistan live
Our results demonstrate the efficacy of DNP and conservation measures that are used inside the protected area’s borders but that may be extended into neighbouring areas
To detect the bear distribution and landscape connectivity in Pakistan’s DNP and neighbouring areas
we used a combination of species distribution models and connectivity simulation
Our research shows that the core bear population and distribution are well protected in DNP; however
about 27% of the pathways used by bears were found outside of protected area boundaries
We discovered a gap in the protection of corridors by crossing these ecological elements with already-existing protected areas
we propose establishing new protected areas strategically positioned to successfully defend the bear distribution and ecological corridors
as well as the evaluation of development plans
must incorporate this spatially explicit prioritisation in order to effectively balance the conflicting demands of development and sustainable conservation initiatives
as well as to guarantee the long-term survival of threatened species
Further inquiries can be directed to the corresponding authors
LB was funded by the National Recovery and Resilience Plan (NRRP)
Project title “National Biodiversity Future Center - NBFC”
We would like to express our gratitude to the Editor Oana Moldovan and the two reviewers for the really positive feedback and helpful comments that supported this final version of the manuscript
Wildlife & Environment Department Government of Gilgit-Baltistan for their assistance during the fieldwork activities and also appreciate Abuzar Ahmad (Game watcher
DNP) help during the camera trapping process
We also sincerely acknowledge the logistical support provided by the Snow Leopard Foundation in Pakistan
The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fevo.2024.1477480/full#supplementary-material
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Copyright © 2025 Fida, Mohammadi, Almasieh, Bosso, Ud Din, Shamas, Nawaz and Kabir. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
*Correspondence: Muhammad Kabir, a2FiaXJfYWprQGhvdG1haWwuY29t; Luciano Bosso, bHVjaWFuby5ib3Nzb0BjbnIuaXQ=
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Volume 10 - 2022 | https://doi.org/10.3389/fevo.2022.1020703
Conflicts between humans and Asiatic black bears (Ursus thibetanus) are widespread in Asia and pose challenges to human-bear coexistence
Identifying effective mitigation measures requires a thorough understanding of human-bear conflicts (HBC)
We assessed spatial-temporal patterns of HBC and their impact factors around the Baoshan Section of the Gaoligongshan Nature Reserve (GNNR) between 2012 and 2020
The results suggested that crop raiding by bears occurred most commonly
HBC hotspots occurred near the protected area where local people frequently encountered bears
The landscapes with lower elevation and human density were at higher risk of HBC
villages with more fragmented forests or less fragmented croplands were more vulnerable to HBC
The differences in agricultural structures contributed to the diverse composition of HBC between the two regions
crop raiding by bears decreased significantly
probably due to the changing landscape composition and configuration derived from human behaviors
yet livestock depredation and beehive loss increased
Our findings indicated the complex interrelationship between the environment
which could guide the implementation of mitigation measures
We recommend multiple approaches based on a social-ecological system to mitigate HBC
which impacts species conservation and jeopardizes human livelihoods and safety
bringing a tremendous challenge for bear conservation
which may change the environment and human-bear interactions
A thorough understanding of HBC is the basis for identifying effective policies and measures to promote long-term human-bear coexistence
We explored the spatial-temporal patterns of HBC and their determiners around GNNR with the following objectives: (1) to identify the hotspots of HBC; (2) to examine the impact of environmental factors on HBC occurrence and composition; (3) to explore the temporal fluctuations and trends in HBC and their possible causes; and (4) provide potential measures to mitigate bear damage
where humans often overlap with black bears
leading to the continuous occurrence of HBC around BSGN
The map shows locations of the Baoshan Section of Gaoligongshan Nature Reserve and study area
Yunnan is one of the first provinces in China to implement a Wildlife Damage Compensation Program (WDCP) (National Forestry and Grassland Administration, 2008)
Data on HBC incidents from 2012 to 2020 were sourced from the WDCP database provided by BSGN
and compensation) from documents such as applications
We categorized HBC occurrences as crop raiding
To explore the spatial and temporal pattern of HBC
we extracted the location and time of HBC occurrence
As most incidents only included the villages where the event occurred
we could not conduct analyses at a finer spatial scale than villages
Maps showing the study area (A) the townships and villages
(B) the villages experienced human-bear conflicts; and the hotspot of human-bear conflicts for (C) all types combined
(D) crop raiding; (E) livestock depredation
The lower limit of MESH is constrained by the cell size ratio to landscape area and is achieved when the corresponding patch type consists of a single-pixel patch
This analysis was created using ArcGIS 10.6 (ESRI Inc.)
we compared the composition of HBC between two regions using the Chi-square test that determines if there is dependence (association) between the two classification variables (i.e.
We used Mann-Whitney U-test to test whether there is a difference in the occurrence of specific HBC between the two regions
Because HBC occurrence does not meet normal distribution
the non-parametric counterpart to the t-test for independent samples
is more suitable for our response variable
Most payments were provided to families as relief for livestock depredation (33.55%)
followed by a relative who died or was injured in a bear attack (25.17%)
Details of human-bear conflicts around Baoshan Section of Gaoligongshan Nature Reserve during 2012–2020
Proportion of different types of human-bear conflicts in the western and eastern region around Baoshan Section of Gaoligongshan Nature Reserve during 2012–2020
Results of the Poisson regression analysis relating human-bear conflicts to various covariates around Baoshan Section of Gaoligongshan Nature Reserve during 2012–2020
Temporal patterns of human-bear conflicts showing (A) all types combined
(B) crop raiding; (C) livestock depredation
(D) beehive loss around Baoshan Section of Gaoligongshan Nature Reserve during 2012–2020
Fragmented cropland patches probably increase bears’ cost of inter-crop-patch movement
leading to a low likelihood of crop-raiding in more fragmented cropland landscapes
there is a lack of detailed data about the availability and distribution of anthropogenic food (i.e.
Further studies are needed to verify these inferences
beehives and livestock are still laid out in forests near bear habitats
we inferred that bears switched from corn to honey/livestock due to the increasing cost of crop raiding
making more beehives and livestock damaged by bears
the increase in beehive loss and livestock depredation might be related to their increasing availability
which needs to be verified by field surveys
High platforms could be explored and implemented to compensate beekeepers who suffered severe damage
The raw data supporting the conclusions of this article will be made available by the authors
DL and FL were responsible for coordinating the manuscript
and JT were co-authors and contributed to structuring of the article
All authors contributed to the article and approved the submitted version
This research was funded by the National Natural Science Foundation of China (Grant no
41301054) and Chinese Academy of Forestry Research Fundamental Research Fund Project (Grant no
We are grateful to the Animals Asia Foundation and the staff of Baoshan Section of Gaoligongshan Nature Reserve
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This article is part of the Research TopicTracking Marine Megafauna for Conservation and Marine Spatial PlanningView all 35 articles
Satellite telemetry (ST) has played a critical role in the management and conservation of polar bears (Ursus maritimus) over the last 50 years
ST data provide biological information relevant to subpopulation delineation
and accurate estimates of vital rates and abundance
Given that polar bears are distributed at low densities over vast and remote habitats
much of the information provided by ST data cannot be collected by other means
Obtaining ST data for polar bears requires chemical immobilization and application of a tracking device
Although immobilization has not been found to have negative effects beyond a several-day reduction in activity
over the last few decades opposition to immobilization and deployment of satellite-linked radio collars has resulted in a lack of current ST data in many of the 19 recognized polar bear subpopulations
we review the uses of ST data for polar bears and evaluate its role in addressing 21st century conservation and management challenges
which include estimation of sustainable harvest rates
understanding the impacts of climate warming
and assessing potential anthropogenic impacts from tourism
We found that in subpopulations where ST data have been consistently collected
information was available to estimate vital rates and subpopulation density
and inform management related to subsistence harvest and regulatory requirements
a lack of ST data in some subpopulations resulted in increased bias and uncertainty in ecological and demographic parameters
which has a range of negative consequences
As sea-ice loss due to climate warming continues
there is a greater need to monitor polar bear distribution
We conclude that continued collection of ST data will be critically important for polar bear management and conservation in the 21st century and that the benefits of immobilizing small numbers of individual polar bears in order to deploy ST devices significantly outweigh the risks
the SLRTs were housed in collars that weighed approximately 5 kg and were fastened with a harness consisting of steel cables covered by plastic and rubber tubes
The cables were fastened by a magnesium bolt under the chest to allow for release when the bolt corroded
Figure 1 Different types of satellite tags (ST) on polar bears: (A): ARGOS Satellite collar (Telonics)
(B): Satellite ear-attached tag (Wildlife Computers
(C): Satellite ear-attached tag (Telonics)
and (D): Glue-on satellite tag (Wildlife Computers
Collars have been the most robust and reliable way to collect multi-year data from polar bears
George Durner/USGS (C) and Karyn Rode/USFWS (B
we review available information on the effects of chemically immobilizing and attaching SLRTs to polar bears
We examine a suite of scientific areas where ST data have been critical to management and conservation
including the value of auxiliary information collected during ST deployments
We conclude by making the case that ST data from polar bears will be critical to inform management decisions in the 21st century as climate warming increasingly impacts polar bear subpopulations and as human activities in the Arctic increase
We also discuss potential ways to reduce concerns about possible effects of ST studies on polar bears
Polar bears must be chemically immobilized to deploy SLRTs (Stirling et al., 1989)
Drugs are usually administered via helicopter-based darting
although in some areas bears on land are captured in culvert traps or darted from snowmobiles
Ground-darting of polar bears is relatively rare due to safety risks associated with not being able to control the animal’s movement from the time a drug is injected to the point at which the animal becomes immobilized
Bears typically remain immobilized and sedated for up to one hour
microchip) or re-identify a previously captured individual
Captured polar bears are typically marked with unique numerical identifiers applied as lip tattoos and/or ear tags
and with a more visible but non-permanent mark using fur dye
which can be used to determine if and when a harvested bear was previously immobilized
Capturing females at dens is now largely avoided
Survival of cubs was similar for adult females that had
including immobilization and deployment of SLRTs on polar bears
must be approved by national agencies and Institutional Animal Care and Use Committees
Figure 3 A satellite-collared female polar bear in East Greenland feeding on a harp seal kill in July 2019
and the collar deployed two years before the photo was taken
This bear would score high on a body condition index
Several scientific studies have demonstrated that the presence of satellite telemetry devices does not impact body condition over the long term
There have been no attempts to use implanted transmitters on polar bears since 1997
Three adult female polar bears shown when satellite telemetry collar was deployed (left) and when it was removed (right)
B) show bear D24042 from East Greenland after one year
D) show bear X35260 from Kane Basin after two years
F) show bear D7388 from Baffin Bay after four years
Satellite telemetry collars can be deployed for different durations and controlled by release mechanisms or removal upon recapture
Discoloration is matted hair under the collar
which can affect population viability (e.g.
via source-sink dynamics or small-population effects)
Distances moved by polar bears in these figures are upwards of 3,500 km across the polar basin
During an assessment of the Baffin Bay and Kane Basin subpopulations, current and historical ST data showed that both subpopulations had redistributed due to sea-ice loss (Laidre et al., 2018a; Laidre et al., 2018b; Laidre et al., 2020a; Laidre et al., 2020b; Atkinson et al., 2021)
ST data identified that the definition of this subpopulation had changed over time because capture-recapture studies in the 1990s did not fully sample the subpopulation’s autumn range
comparison of abundance estimates between the 1990s and 2010s would have led to a biased assessment of subpopulation trend
Figure 6 Track of a satellite-collared adult female polar bear that swam north from Alaska (Southern Beaufort Sea subpopulation) through ice-free waters from 25 August to 4 September 2008. For details see Durner et al. (2011)
which allowed estimation of reproductive rates
Identifying these divergent behaviors and their potential impacts on vital rates aids in developing and interpreting population models
Figure 8 A polar bear walking through oilfield infrastructure near Prudhoe Bay on the Arctic coastal plain of Alaska
which is home to a large industrial footprint
Figure 9 Overview of the uses of satellite telemetry data for conservation and management of polar bears
together with the consequences of not having satellite telemetry data
ST will become increasingly important as future research and monitoring efforts rely on sampling smaller numbers of animals
there has been a shift away from physical-capture studies and toward less-invasive sampling methods (e.g.
which also facilitate the collection of fewer basic life-history data useful for demographic modeling
critical to designing less-invasive studies as sea-ice conditions deteriorate and polar bear distribution changes
It also will not be possible to extrapolate to unsampled areas and interpret changes in estimated abundance over time (i.e.
delineating true change in abundance from changes in distribution); see section 3.1
Figure 10 Satellite telemetry data allow for identifying shifts in polar bear space use over time and have proven critical to interpreting data collected during population assessments (e.g., Laidre et al., 2020a)
These data from the Baffin Bay subpopulation demonstrated large shifts in seasonal space use over two decades
Without ST data or methods to correct estimates of abundance for polar bear movements
managers can expect bears may be “double-counted” in capture-recapture studies of adjacent subpopulations that experience immigration and emigration
This can artificially inflate abundance estimates
resulting in overharvest or misapplication of policy decisions that require accurate estimates of abundance
such as negligible impact determinations under the U.S
ST data are needed to build RSFs (see section 3.3) that identify essential habitats and project their future availability under different greenhouse gas emission scenarios (Amstrup et al., 2010; Atwood et al., 2016a)
Habitat assessments are a fundamental requirement for implementation of protected species legislation in a warming Arctic
Article II of the 1973 Agreement on the Conservation of Polar Bears requires the contracting parties to “take appropriate action to protect the ecosystems of which polar bears are a part
with special attention to habitat components…”
the Polar Bear Range States Circumpolar Action Plan (CAP) considered goals for defining essential habitat and multiple other agreements on polar bears (e.g.
Article 2 of the U.S-Russia Polar Bear Agreement; United States T
107-10) require the identification and conservation of key polar bear habitats
Projections of future polar bear habitats will also require ST data combined with projections of pollutant transport to and dynamics in Arctic ecosystems to predict future exposure to contaminants
If a radio-collared animal approaches a delineated protected area
the RAG unit activates a non-lethal deterrent (e.g.
sound effects) to discourage the animal from advancing
ST represents a valuable tool for monitoring the risks that polar bears can pose to human safety and reducing conflicts through both reactive (e.g.
monitoring the movement of translocated bears) and proactive (e.g.
Figure 11 Movements of an adult female polar bear near Longyearbyen
The Telonics iridium collar was set to collect GPS positions every other hour and report them every second day
When the collared bear moved inside a circle with radius of 25 km (‘geo-fence’) from Longyearbyen
the collar sent data more frequently (collecting a GPS location every hour and reporting every 4th hour) so the bear’s proximity to town could be monitored (C)
ST data are likely to be important to understanding the impacts of the fast-growing ship-based and terrestrial ecotourism industry focused on viewing polar bears in their natural habitats
Understanding movements and seasonal habitat use of bears can help guide future regulations so that ecotourism activities avoid sensitive habitats
preliminary capture-recapture analyses for the Viscount Melville subpopulation failed to produce biologically plausible results
whereas subsequent analyses that used ST data led to more accurate estimates of survival and abundance
Here we identify three methods that may facilitate collection of ST data and reduce concerns
Table 1 Number of bears instrumented with satellite tags (ST) (any type) by subpopulation over the last 40 years
and stakeholders should review the status of polar bear subpopulations
identify what information is most important to management and conservation
and determine appropriate methods to collect it
This requires discussing the pros and cons of all research methods and identifying the ramifications if ST data are not collected
The discussion should extend to impacts on management decisions (e.g.
regarding sustainable harvest level) and potential ramifications for resource users
decisions about whether to collect ST data and the number of bears to be fitted with SLRTs can be based on a transparent assessment of the most effective research methods available to meet objectives
while recognizing approaches vary between subpopulations
collaborative discussion could lead to a better understanding of concerns around ST and help identify mutually acceptable solutions
improvements to study design and parameter estimation that result from ST data mean that sample sizes of other types of data (e.g.
from biopsies) can be substantively reduced while still meeting research objectives
A release mechanism can be programmed for collars to drop off on a specific date or bears can be recaptured and collars manually removed
These approaches require balancing multiple tradeoffs
given that sample sizes and how long individuals wear SLRTs is positively correlated with the probability that ST data will reveal individual variability in the behavior and the adaptive potential of polar bears
Improvements in SLRTs have the potential to alleviate concerns about effects on polar bears. Size reduction of collars, reliable release mechanisms, and tags that serve as alternatives to collars for short-term data collection, are all useful areas of development (e.g., Wiig et al., 2017)
Several such efforts have occurred in recent years but continued technological advances warrant ongoing investment in methods for tracking polar bears
Although much of the current understanding of movements of polar bears comes from the deployment of ST collars on adult females
development of SLRTs that enable the tracking of adult males and juvenile bears for a year or more
which are specifically designed to identify temporary effects on reproduction
or other demographic parameters following capture
ST data from these regions and their respective subpopulations will be critical to conservation and management of the species
ST provides critical data that allow managers to make informed management and regulatory decisions and ST will be vital to the conservation of polar bears in the 21st century
KL lead the writing with contributions from GD
Authors were supported by their individual agencies
KL was supported by NASA grant 80NSSC18K1229
The reviewer LQ declared a past co-authorship with one of the authors [KL
This review was a product of an international scientific research workshop (“Polar bear demography: status and future direction”
12-14 February 2019) under the umbrella of the Polar Bear Range States Circumpolar Action Plan (CAP)
Nick Cobbing kindly gave us permission to use his photo
or product names is for descriptive purposes only and does not imply endorsement by the U.S
and one anonymous reviewer made helpful comments
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“People are gifted with unique qualities and everyone can shine and build a career to match their abilities
especially if they have the right support early on
We know that there are still stereotypes about which roles are more suited to women – or men
and through this mentoring program we want to open the door to the vision of a career in technical or sales to young women who feel they would fit in
but who may feel discouraged from taking the first step
The program has been a good match for me from the start and I’m glad that I will be able to mentor myself
alongside other colleagues who will share their valuable experiences.” said Gabriela Crețu
Launch conference: online, on November 6, at 10:00
In the first year that Ursus Breweries is organizing the “Brew your story” program
the company is offering 16 places to young women who want to develop their personal and professional skills under the guiding hand of one of the 16 mentors from the Ursus Breweries team
The mentors have experience in departments as diverse as HR (Head of Talent and Development
Marketing (Brand Managers & Senior Brand Managers)
selected mentees will receive a monthly 1-on-1 mentoring session
depending on each team’s preference and schedule
regardless of the specific college being studied
The mentoring program application form will be shared during the conference on November 6
Ursus Breweries is the largest beer producer in Romania, being the beer market leader. The brands in the Ursus Breweries portfolio are: URSUS, Timișoreana, Ciucaș, Peroni Nastro Azzurro, Kozel, Azuga, Pilsner Urquell, Asahi Super Dry. Ursus Breweries currently owns 3 breweries: in Brasov, Buzău and Timisoara and a mini-facility in Cluj-Napoca. Ursus Breweries is part of Asahi Europe & International.
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providing social media features and to analyse how our website is used
declared in an interview with state news agency PAP that he intends to revive Ursus’ production capacity
aiming to finalize the takeover and unveil a five-year development plan by the first quarter of 2025
“Ursus had competitive products and loyal customers
It was not market conditions but mistakes by the previous management that led to its collapse,” said Krot
a 41-year-old Ukrainian entrepreneur and co-owner of the Techiia holding
“Our company has the resources to modernize the plants in Lublin and Dobre Miasto and rehire staff
Krot noted “significant demand” for Ursus-class tractors in parts of Africa—particularly Tanzania
and Uganda—as well as in Ukraine and other European countries
will be rebuilding Ursus’ distribution channels
which had deteriorated under the previous leadership
With just 117 employees—down from a workforce of 1,000—Ursus requires an urgent infusion of capital and technology to resume large-scale production
Krot pledged to update the factories’ machinery
and conduct audits of both technical documentation and energy efficiency
“We’re finishing an audit of the technical documentation and plan to renew Ursus’ ISO 9001 certification,” Krot explained
we’ll present a five-year roadmap for growth.”
Ursus began by producing industrial equipment before shifting to tractor manufacturing in the early 1920s
After decades of expansion and post-war restructuring
M.I. Crow purchased Ursus in October 2024 for PLN 74 million (~USD 18 million), acquiring two production plants (in Dobre Miasto and Lublin) as well as the Ursus trademark.
Krot, who has a background in crisis management and agricultural technology, believes the storied brand still holds strong recognition. “I quickly realized Ursus could be rebuilt, and I’m confident we can achieve that,” he said.
First Look at M/Y URSUS: The 30m Explorer Being Rebuilt at Balk Shipyard By Frances Flannagan
22 Jul 2024 Having arrived at Balk Shipyard in 2022
the exteriors of Amico’s motor yacht URSUS have been revealed to the industry for the first time
This now-pocket explorer yacht will be rebirthed as a larger vessel by six metres
whilst also featuring more spacious areas and a spectacle of technical upgrades
Two years ago, the 24m Acico URSUS arrived at Balk Shipyard for a complete rebuild
with both her interior and exterior design completely reimagined
Her stern and bow sections have successfully been transformed
and she will leave the yard as a 30.36m pocket explorer vessel.
Mulder Design and the Owner’s team have worked closely with Balk on this rebuild
with the main objective being the enhancements of her seakeeping abilities and the onboard living areas
New naval architecture and exterior design were penned by Mulder
who is also set to oversee the interior styling in collaboration with the Owner’s team.
‘We have been honoured to be working with involved and passionate owners for this project
They are experienced yachtspeople who want to maximise the enjoyment they get from their vessel,’ commented Evan Kortmann
‘This is a dramatic rebuild and MY Ursus will not only leave larger than when she arrived
Mulder Design has beautifully reimagined the vessel; it’ll be hard to believe this is the same yacht.’
The deck areas are set to be overhauled and re-mapped
whilst the upper deck will be extended to make the living areas even more spacious
A plethora of significant upgrades will enhance URSUS’ onboard experience even further
including the additions of a new al fresco kitchen
a renewed beach club and a reformed layout that will increase crew accommodation.
With a notable history of complex refits, rebuilds and extensions in its portfolio, Balk Shipyard was the perfect choice for this stunning reimagining of URSUS. A key redelivery was the refit on Feadship’s EMERALD
that included a 3m stern extension and has since been a highly successful charter vessel.
The shipyard boasts a wealth of expertise that has been developed over two centuries of shipbuilding
and has many third-generation employees making up its exceptional in-house team
Its significant location in the Netherlands
one of the main superyacht hubs on the planet
enhances Balk’s services even further
with an astounding network of both local and global partners lending their expertise when required
Balk Shipyard is also situated just an hour away from Amsterdam with Lelystad Airport even closer
making the shipyard highly accessible for Owners and their representatives across the world.
and we at Superyachts.com cannot wait to witness this exceptional rebirth
"This is a dramatic rebuild and MY Ursus will not only leave larger than when she arrived
Metrics details
The endangered Formosan black bear (Ursus thibetanus formosanus) is the largest native carnivorous mammal in Taiwan
and habitat destruction are serious threats to the survival of bear populations
studies on the impact of diseases on bear populations are limited
this study aimed to establish a database of the hematological and plasma profiles of free-ranging Formosan black bears and investigate the occurrence of ectoparasites
Formosan black bears were captured in Yushan National Park (YNP) and Daxueshan Forest Recreation Area (DSY) in Taiwan
Blood samples were collected from each bear for hematological analysis and plasma biochemistry using a hematology analyzer
Parasites and pathogens were detected using a thin blood smear with Wright–Giemsa staining and polymerase chain reaction (PCR) assay
macroscopic ectoparasites were collected from bears to detect blood parasites and other pathogens
the relationships between the bear variables (sex
21 wild bears (14 in YNP and 7 in DSY) were captured and released during the satellite tracking studies
Hematological analysis and plasma biochemistry indicated significant differences in white blood cells (WBC)
and lactate dehydrogenase (LDH) levels between foot snare and culvert-captured bears
there were significant differences in total plasma protein (TPP)
and K+ levels between male and female bears
pathogen-infected bears had significantly higher erythrocyte sedimentation rate (ESR; 30 min and 1 h) and globulin levels than uninfected bears
among which eight adult tick species were identified
PCR revealed that 13 (61.90%) and 8 (38.10%) bears harbored Hepatozoon ursi and Babesia DNA
157 (65.41%) and 128 (53.33%) samples were positive for H
this is the first study to establish a database of the hematological and plasma profiles of wild Formosan black bears and investigate ectoparasite infestation and Hepatozoon and Babesia spp
these findings may serve as a reference for monitoring the health and population of locally endangered bears
knowledge of potential infectious and vector-borne pathogens in Formosan black bears is still lacking
it is anticipated that this study will provide useful information for the conservation and management of endangered Formosan black bear populations
The setting of (a) snare and (b) culvert traps and sample collection for (c) subadult and (d) adult Formosan black bears
All samples were transported within 3 days to the Veterinary Medical Teaching Hospital and the Laboratory of Public Health and Epidemiology
National Pingtung University of Science and Technology for morphological identification and laboratory processes
At least six thin Wright–Giemsa stained blood smears were obtained from each bear [39]
Microscopic examination was performed to explore the morphology of blood cells and identify the presence of blood parasites
mean corpuscular hemoglobin concentration (MCHC)
White blood cell classifications were performed using an IDEXX ProCyte Dx Hematology analyzer instrument (IDEXX Laboratories Inc.,Westbrook
whereas the remaining blood parameters were analyzed using the Mythic 18 Vet hematology analyzer instrument (Orphee SA
erythrocyte sedimentation rate (ESR; 30 min and 1 h) and platelet fibrinogen (Fib) levels were analyzed using the Wintrobe method and heat precipitation fibrinogen test
The Fujifilm Dri-Chem 3500 s instrument (Fujifilm
Japan) was used to measure the following 28 plasma biochemical parameters: total plasma protein (TPP)
and chloride (Cl−) electrolytes were analyzed using EasyLyte PLUS (Medica Corporation
and plasma iron levels were determined using the Kodak Ektachem DT60 analytical system with DTE and DTSC II modules
each tick was individually placed in a microcentrifuge tube containing 70% ethanol and stored at 4 °C for DNA extraction
Blood and tick samples were collected to detect parasitic and tick-borne pathogens
Tick samples were dissected in sterilized 1 × PBS
the whole body was cut and manually homogenized
whereas each adult tick was cut into approximately two halves
Half of each adult tick sample was transferred to a clean microcentrifuge tube for DNA extraction
A total of 100 µL of sterile 1 × PBS was added to each tube and stored at 4 °C until DNA extraction
The other half was stored in 70% ethanol as a backup
DNA was extracted from blood and tick samples using the DNeasy Blood and Tissue kit (Qiagen
All DNA samples were eluted into a 100 µL final volume and stored at −20 °C until used for blood parasite and pathogen detection
and distilled water (negative control) were used for the PCR assay
PCR products were separated using a 2% agarose gel stained with nucleic acid stain (50 ppm EtB “out” nucleic acid staining solution
and the results were visualized with UVIdoc HD5 (Uvitec
PCR products were purified using a Plus DNA Clean/Extraction Kit (GMbiolab Co.
Taiwan) and sent for nucleotide sequencing (Genomics BioScience and Technology Co.
The sequence data were compared with known sequences deposited in the GenBank database using the National Center for Biotechnology Information (NCBI) nucleotide Basic Local Alignment Search Tool (BLAST)
the validated sequences were aligned and analyzed using MegAlign (DNASTAR
All statistical analyses were performed using GraphPad Prism version 8.4.2
The numerical data of each blood parameter were summarized as medians
Comparisons of blood parameters between each bear variable of the bears
were performed using unpaired t-tests for parametric data and Mann–Whitney U tests for non-parametric data
multiple comparisons of blood parameters among pathogen infection
and non-infection statuses of the bears were performed using the Kruskal–Wallis test
and P < 0.05 was considered statistically significant
The relationships between bear variables (sex
and area) and blood parasite and pathogen infection status; tick variables (sex
and area) and pathogen harboring status; and bear variables (sex
and occurrence of blood parasites and pathogens) and the presence of blood-parasite- and pathogen-carrying ticks were analyzed using the chi-square test
A two-tailed Fisher’s exact test was used when the expected number of observations was less than five
five bears were captured by snares in 2014–2015
while the rest were captured by culvert traps in 2015–2021
The beak-like protrusion at one end of the slightly curved gamont of H
ursi (arrowed) found in thin blood smears of Formosan black bears
there was no significant difference in Babesia infection rates among ticks of different sexes or life stages
Ticks collected from Babesia-positive bears were more likely (P < 0.00001) to harbor Babesia spp
than those collected from Babesia-negative bears [65.30% (96/147) versus 34.40% (32/93)]
there were no significant differences in H
ursi detection rates between ticks collected from H
these differences in hematological values could be species-specific or caused by differences in food resources
these hematological and plasma data may serve as a reference for future investigation on host and tick-borne pathogen relationships in wild bears
and LDH values were elevated in snare-captured bears
which may be attributed to potential stress and muscle injuries
diagnosing muscle injuries in bears requires physical examinations and imaging
Information based on satellite tracking and blood testing results seemingly can only reveal temporary muscle injuries in snare-captured bears
snare traps should only be applied in remote areas with poor accessibility or emergency conditions
and when traps can be monitored in real time or checked daily
Phylogenetic analysis and data of tick species in other animals in the same area would be helpful in investigating the distribution and sources of A
these results indicate that black bears can be infected by several Babesia spp
found in this study showed a 90.6–95.5% sequence similarity with known Babesia spp.
highlighting the importance of conducting additional amplification and sequencing of the full-length 18S rRNA gene or other specific genes of Babesia to achieve a more detailed genetic characterization
the role of black bears as potential wildlife reservoirs of Babesia and other vector-borne pathogens warrants further investigation
flava plays an important role in Hepatozoon transmission to wild black bears
flava for Hepatozoon transmission requires further study
female ticks have a larger physiological demand for blood because they require it for engorgement prior to egg laying
This engorgement process provides them with additional opportunities to acquire pathogens from the host
BLAST analysis revealed that Babesia DNA samples from ticks matched several species of Babesia
Although the species of Babesia was not identified due to the wide host range of ticks
we showed that ticks that infest Formosan black bears may be infected by several species of Babesia
ticks on bears captured in DSY were more likely to harbor Babesia spp
To further clarify whether the location affects the prevalence of Babesia infection in vectors
Babesia should be detected in ticks from the same environment
the different results can be attributed to various factors
Comprehensive epidemiological surveys of parasites and other pathogens
these findings emphasize the potential risk of zoonotic pathogen transmission
testudinarium infested Formosan black bears
both species may potentially infest humans and increase the risk of zoonotic diseases
such as SFTS and febrile illness caused by the Oz virus in Taiwan
All data generated or analyzed during this study are included in this published article
Usefulness of the umbrella species concept as a conservation tool
Population viability analysis of Formosan black bears (Ursus thibetanus formosanus)
Pingtung: National Pingtung University of Science and Technology; 2013
Infectious disease and the conservation of free-ranging large carnivores
Seasonal variations in the hematology and physiology of black bears
Evaluating condition of Alaskan black bears with blood profiles
Blood chemistry of the brown bear (Ursus arctos) from southwestern Yukon Territory
Seasonal variations in physiologic functions of arctic ground squirrels and black bears
First report of clinical disease associated with canine distemper virus infection in a wild black bear (Ursus americana)
Serologic evidence of West Nile virus infection in black bears (Ursus americanus) from New Jersey
Serologic survey for infectious canine hepatitis virus in grizzly bears (Ursus arctos) from Alaska
Hematological profiles of the Formosan black bear (Ursus thibetanus formosanus)
cytochemistry and ultrastructure of blood cells in Asiatic black bear (Ursus thibetanus)
Blood chemistry reference intervals of captive Asiatic black bears (Ursus thibetanus)
and hematology of the black bear in New York
(Apicomplexa: Hepatozoidae) in Japanese black bear (Ursus thibetanus japonicus)
Molecular prevalence and characterization of Hepatozoon ursi infection in Indian sloth bears (Melursus ursinus)
Filarial parasites from the black bear of Japan
Ticks and tick-borne pathogens of black bears (Ursus americanus) in New Jersey
Detection of human bacterial pathogens in ticks collected from Louisiana black bears (Ursus americanus luteolus)
Parasites from the Asiatic black bear (Ursus thibetanus) on Kyushu Island
Geographical distribution of Demodex ursi in black bears from Florida
and condition evaluation of black bears in northcoastal California
Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida
Seasonal variation in haematological and biochemical variables in free-ranging subadult brown bears (Ursus arctos) in Sweden
and season on serum chemistry values of brown bears in Croatia
The relative abundance and the distribution prediction models of Formosan black bears (Ursus thibetanus formosanus)
Pingtung: National Pingtung University of Science and Technology; 2011
Prebaiting and snaring techniques for black bears
Techniques for live-trapping and handling black bears
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and zolazepam for the immobilization of black bears
Immobilization of grizzly bears (Ursus arctos) with dexmedetomidine
Aging black bears from first premolar tooth sections
Relationship between tooth wear and age in the Japanese black bear in Hiroshima Prefecture
Activity patterns of Asiatic black bears (Ursus thibetanus) in the Central Mountains of Taiwan
and atipamezole in nondomestic mammals: a review
Bartonella infection in shelter cats and dogs and their ectoparasites
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Economic insect fauna of China Fasc 39 Acari: Ixodidae
Studies on endoparasites of the black bear (Ursus americanus) in the southeastern United States
The first detection of Babesia species DNA from Japanese black bears (Ursus thibetanus japonicus) in Japan
Identification and phylogenetic analysis of Dirofilaria ursi (Nematoda: Filarioidea) from Wisconsin black bears (Ursus americanus) and its Wolbachia endosymbiont
Analysis of the 18S rRNA gene sequence of a Hepatozoon detected in two Japanese dogs
identified by PCR in ticks collected from domestic and wild ruminants in southern Switzerland
Differentiation of Bartonella-like isolates at the species level by PCR-restriction fragment length polymorphism in the citrate synthase gene
Genotypic identification of Rickettsiae and estimation of intraspecies sequence divergence for portions of two rickettsial genes
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and seasonal differences in the blood profile of black bears captured in northeastern Pennsylvania
Serum chemistry and hematology of black bears: physiological indices of habitat quality or seasonal patterns
Analysis of the blood of American black bears
Clinical and laboratory findings associated with naturally occurring babesiosis in dromedary camels
Clinical and laboratory findings of Babesia infection in dogs
Haemato-biochemical changes in Babesia infected cattle
A retrospective study of clinical hematology and biochemistry of canine hepatozoonosis on hospital populations in Bangkok
Haematobiochemical changes in dog affected with Babesia canis
The first report on Hepatozoon canis in dogs and wolves in Poland: clinical and epidemiological features
Evaluating welfare of American black bears (Ursus americanus) captured in foot snares and in winter dens
The ixodid ticks collected from dogs and other animals in Taiwan and Kinmen Island
Department of Parasitology and Tropical Medicine
Catalogue and bibliography of ticks and mites parasitic on vertebrates in Taiwan
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with notes on its biology and conservation
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Absence of trypanosomes in polar bears (Ursus maritimus) from Svalbard
Diseases and mortality in free-ranging brown bear (Ursus arctos)
Detection of multiple intracellular bacterial pathogens in Haemaphysalis flava ticks collected from hedgehogs in central China
Taxonomic studies of Haemaphysalis flava (Neumann)
its seasonal prevalence and role in parasitic diseases of sheep/goat in Balochistan
Tick-borne pathogens in ticks collected from birds in Taiwan
Molecular detection of severe fever with thrombocytopenia syndrome and tick-borne encephalitis viruses in ixodid ticks collected from vegetation
Experimental infection of adult and juvenile coyotes with domestic dog and wild coyote isolates of Hepatozoon americanum (Apicomplexa: Adeleorina)
Experimental transmission of Hepatozoon americanum Vincent-Johnson et al.
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Tissue “cysts” of Hepatozoon griseisciuri in the grey squirrel
Sciurus carolinensis: the significance of these cysts in species of Hepatozoon
Transmission of Hepatozoon americanum (Apicomplexa: Adeleorina) by ixodids (Acari: Ixodidae)
Experimental transmission of Hepatozoon americanum to rodents
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Myocarditis and myositis due to infection with Hepatozoon species in pine martens (Martes martes) in Scotland
Diversity of Hepatozoon species in wild mammals and ticks in Europe
in Ursus americanus (black bear) in New Jersey
and tick infestations in Oklahoma black bears (Ursus americanus)
in American black bears (Ursus americanus) from eastern and western North Carolina
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Babesiosis of wild carnivores and ungulates
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Molecular evidence of the multiple genotype infection of a wild Hokkaido brown bear (Ursus arctos yesoensis) by Babesia sp
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Trichodectes euarctidos (Phthiraptera: Trichodectidae)
Demographic characteristics and infectious diseases of a population of American black bears in Humboldt County
Molecular and morphological identification of a human biting tick
First report of human biting activity of Ixodes acutitarsus (Acari: Ixodidae) collected in Taiwan
Hard ticks (Acari: Ixodida: Ixodidae) parasitizing humans
Human case of severe fever with thrombocytopenia syndrome virus infection
Haemaphysalis longicornis ticks as reservoir and vector of severe fever with thrombocytopenia syndrome virus in China
Detection of SFTS virus in Ixodes nipponensis and Amblyomma testudinarium (Ixodida: Ixodidae) collected from reptiles in the Republic of Korea
The first discovery of severe fever with thrombocytopenia syndrome virus in Taiwan
Characterization of a novel thogotovirus isolated from Amblyomma testudinarium ticks in Ehime
Japan: a significant phylogenetic relationship to Bourbon virus
IUCN. 2022. The IUCN red list of threatened species. Version 2022-2. https://www.iucnredlist.org
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We thank the Forestry and Nature Conservation Agency and Yushan National Park headquarters for providing logistical support
We are also grateful to the many research assistants
We would like to thank anonymous referees for their valuable comments
This research was mainly funded by the National Science and Technology Council
Taiwan: MOST 103-2621-B-020-001 and MOST 104-2621-B-020-001
Yi-Lun Tsai and Wittawat Wechtaisong have contributed equally to this work
National Pingtung University of Science and Technology
Center of Excellence in Animal Vector-Borne Diseases
YLT and MHH: conceptualization and study design; TRL
and MHH: sample and data collection; WW and TRL: validation and formal analysis; YLT
and WW: manuscript writing and editing; MHH: supervision and correspondence
and sampling procedures on bears have been approved by the Forestry and Nature Conservation Agency under the Agreement to the Use of Conserved Wild Animals (No
1031700938 and 1041701149) and the National Pingtung University of Science and Technology Laboratory Animal Care and Use Committee (IACUC No
The authors declare that they have no competing interests
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DOI: https://doi.org/10.1186/s13071-024-06320-7
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was purchased for PLN 74 million (EUR 17 million) in the third attempt to find a buyer
according to private broadcaster Radio Zet
Ursus was finally sold during a third auction
a restructuring firm tried to sell the company for PLN 125 million
before ultimately securing a deal at PLN 74 million
a company established in Warsaw just a few months ago
and the company’s main focus will remain on producing transportation equipment
with additional activities including metal goods manufacturing
Ursus initially operated under the name "Przemysłowe Towarzystwo Udziałowe" and produced industrial fittings
moving into the production of various engines and later changing its name to Zakłady Mechaniczne URSUS S.A
and eventually began producing tractors after World War II
with the first one rolling off the assembly line in 1947
The company grew to become one of Poland's largest enterprises during the communist era
and old debts combined with falling demand for tractors led to financial difficulties
Ursus began selling off assets and attempted multiple restructuring efforts
Although the company seemed to find success in international markets for a time
The new management aims to develop a fresh strategy for the brand
which may include hiring new specialists and boosting production capacity
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European real estate fund GreyKite and Central European developer White Star Real Estate have set up a new €300 mln joint venture focused on logistics real estate
GreyKite has acquired a logistics portfolio in Poland
consisting of three properties strategically located in Warsaw
will continue to play a key role as both asset and property manager
The 142,000 m2 portfolio boasts an occupancy rate of nearly 100%
These properties are situated in prime industrial and logistics hubs within Poland
commented: ‘This transaction is consistent with our strategic focus on scalable investment themes in high-conviction sectors underpinned by compelling fundamentals
The Polish logistics market is benefitting from a number of structural drivers
including the continued trend for nearshoring as a result of its European single market access and relative affordability
We look forward to scaling the JV alongside a best-in-class partner
whilst simultaneously closing in on a number of other high-profile acquisitions.’
added: ‘This acquisition represents an attractive entry point into the logistics sector
In addition to the compelling acquisition yield
asset management and investment initiatives we will look to implement alongside White Star
Greykite and White Star aim to further scale the JV over the next 18-24 months.’
concluded: ’The industrial warehouse and logistics services market in Poland is developing dynamically with supportive fundamentals
We are excited to partner with Greykite in addressing this continuing demand growth for warehouse space and to expand our new JV.’
This acquisition follows the official launch of GreyKite and the fund in March of this year
The fund has secured substantial capital commitments from renowned global investors
GreyKite focuses on investing in real estate assets with strong
long-term fundamentals across various property types in select European markets
White Star Real Estate has completed over 50 development projects of various asset classes and also provides asset and property management services
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This article is part of the Research TopicWildlife WelfareView all 14 articles
Intraperitoneal radio transmitters have been widely used in free-ranging wild mammals
but there are no long-term studies on their biocompatibility or technical stability within the abdominal cavity of animals
Possible negative health effects may bias results from ecological studies on instrumented animals and raise concerns over animal welfare issues
The aim of this study was to evaluate the long-term technical stability and pathological effects of Telonics intraperitoneal very high frequency (VHF) radio transmitters in brown bears (Ursus arctos)
We instrumented 305 individual bears with intraperitoneal VHF radio transmitters during a 19-year period
We surgically removed devices that had been in bears for 1–9 years and collected transmitters from animals that died 1–13 years after implantation
We took biopsies for histopathology from tissue encapsulating implants in live bears
Retrieved transmitters underwent a technical inspection
Of the 125 transmitters removed from live bears
66 were free-floating in the peritoneal cavity [a mean (SD) of 3.8 (1.5) years after implantation]
whereas 59 were encapsulated in the greater omentum [4.0 (1.8) years after implantation]
Histopathology of biopsies of the 1–15 mm thick capsules in 33 individuals showed that it consisted of organized layers of connective tissue
the inner part of the capsule was characterized by a foreign body reaction
We inspected 68 implants that had been in bears for 3.9 (2.4) years
The batteries had short-circuited four (5.9%) of these devices
This resulted in the death of two animals 10 and 13 years after implantation
we found the short-circuited devices to be fully encapsulated within the peritoneal cavity 5 and 6 years after implantation
A significant proportion of the other 64 inspected implants showed serious technical problems
such as corrosion of metal parts or the batteries (50%)
and erosion (7.4%) or melting (5.9%) of the wax coating
We conclude that the wax coating of the transmitters was not biocompatible
that the technical quality of the devices was poor
and that these implants should not be used in brown bears
the focus was on the functional performance of the device
such as battery-life and transmission range
Telonics and other companies have been marketing intraperitoneal radio transmitters for a wide range of wildlife species
Here we present data from a 19-year study on the technical stability and pathological effects of intraperitoneal radio transmitters in free-ranging European brown bears (Ursus arctos)
The present work was part of an ongoing ecological study by the Scandinavian Brown Bear Research Project (SBBRP) (19). From 1997 to 2015, we carried out a total of 446 surgeries according to an established protocol (20) to implant
or remove Telonics intraperitoneal very high frequency (VHF) radio transmitters involving 305 individual free-ranging brown bears [213 yearlings (162 females
the age refers to the time of first implant]
Fifteen bears that previously had their implants removed underwent a second surgery after 1–9 years to receive a new implant
We used the following models (number of units
The basic components of a Telonics IMP/400/L implant are shown in Figure 1
and antenna were enclosed in a thick paper tube
wrapped in thin paper labeled with the company's name and address and the serial number of the device
These components were contained within a plastic shell cylinder with both ends closed with glued-on end caps
The plastic shell cylinder was coated with a 2.1 mm thick wax of unknown composition
Components of a Telonics IMP/400/L intraperitoneal VHF implant (length 15.2 cm
and antenna (central bottom) were enclosed in a thick paper tube (left)
wrapped in thin paper (central middle) labeled with the company's name and address and the serial number of the device
These parts were contained within a plastic shell cylinder (central top) with both ends closed with glued-on end caps (right)
We inspected implants retrieved from live or dead bears for signs of discoloration
the plastic shell cylinder was inspected for signs of fissures or cracks
and the attachment and sealing of the end caps were assessed
The end caps were removed and the internal parts were removed and inspected; the paper wrappings for dryness
the batteries for signs of short-circuiting and leakage
We collected biopsies from the tissue encapsulating the implants
We preserved the tissue samples in 10% phosphate-buffered
Norway) and shipped them to the Norwegian Veterinary Institute (Oslo
When we found pus-like content indicating possible bacterial growth inside the capsules
which were shipped with no cooling to the Norwegian Veterinary Institute for culturing by standard methods within 3 days
Thick tissue capsules (>2 mm) and capsules attached to a twisted loop of the omentum were amputated
We inspected and described biopsies before cutting 3–4 mm thick slices perpendicularly to the longitudinal axis of the capsule
The tissue slabs were dehydrated in ethanol
and embedded in paraffin before 5–6 μm thin sections were made
and stained with haemotoxylin-eosin and van Giessen according to standard procedures
There were two major reasons to use implants in the bears
The SBBRP has a goal to follow individual bears throughout their lives and VHF implants allowed the recapture of individuals with neck collars that had been lost or had malfunctioned
The second reason was to avoid equipping yearling bears with transmitters mounted on neck collars
growing bears would have to be recaptured annually for several years to change the collars
Capture and surgical protocols were approved by the Swedish Ethical Committee on Animal Research (Uppsala
the Swedish Environmental Protection Agency (Stockholm
and the Swedish Board of Agriculture (#31-11102/12)
the 305 individual bears that had received implanted transmitters in our study had the following outcomes: for those still carrying a VHF implant [years refer to time after last implantation
50 were alive 1.4 (±1.3) (0–5) years later
39 were missing (no radio signals) 2.4 (±1.4) (0–6) years later
129 had been shot (legally or illegally) 1.9 (±2.3) (0–13) years later
20 had been killed by another bear 0.8 (±0.9) (0–3) years later
two died due to leakage from short-circuited batteries 10 and 13 years after surgery
two had died from trauma 2 months (hit by a train) and 2 years (crushed by a sliding rock) later
three had died during or shortly after capture (two from drowning and one due to dehiscence of the surgical wound)
and 27 had died from unknown causes 1.3 (1.8) (0–8) years later (inconclusive necropsies
implant found without any remains of the bear)
Of those from which the VHF had been removed (time after removal of the implant)
or malfunctioning of radio collar) 3.1 (±2.4) (0–7) years later
15 were shot 2.1 (±2.2) (0–8) years later
and one had been killed by another bear 1 year later
(A) Proportion of bears with free-floating and encapsulated implant in relation to years with the device
(B) Histological pattern in relation to years with implant
(C) Proportion of capsules with necrosis in relation to years with implant
Two animals (Cases 1 and 2 below) with encapsulated implants had aggregates of thick
opaque and yellowish exudate between the capsule and the implant
One of them (Case 2) also had a 5-cm wide cystic mass of tissue
containing similar exudate attached to the outer surface of the capsule
Bacteriological swabs from both cases were negative
an adult male whose implant was replaced after 3 years
filled with a similar exudate as described above
We inspected 68 implanted transmitters that had been in bears for 3.9 (2.4) (0–13) years
54 transmitters were surgically removed from live bears and 14 were retrieved from dead bears (ten shot by hunters
All implants showed some degree of yellowish discoloring of the wax coating
parts of the wax had partially melted and the underlying plastic shell cylinder was visible
the wax was visibly thinner than on new transmitters
We interpreted this as erosion of the wax due to wear
the plastic shell cylinder had a longitudinal crack
One of the end caps was loose or open in eight (11.8%) of the implants
One (1.5%) implant had visible moisture condensed on the inside of the plastic shell cylinder
moisture had resulted in corrosion of the batteries and other metal parts
Leakage from the batteries was seen in one (1.5%) otherwise intact implant
the batteries had short-circuited (Cases 3–6 below)
The inner layer was otherwise characterized by well-organized
collagen-rich and sparsely cellular connective tissue
greenish or brownish material were often found solitarily or in small aggregates
A significant inflammatory reaction was evident in a third of the biopsies
with the tissue characterized by granulomatous inflammation
The most severe cases contained numerous macrophages
eosinophilic granulocytes constituted a significant proportion of the cellular infiltrate
The capsules from bears that had carried the implant for a long period were generally characterized by a milder inflammatory reaction than those that had carried it for a shorter period
we observed granulomatous inflammation in most of the cases
as only seven of the inspected capsules did not show any inflammatory cellular reaction
The middle layer of the capsule was often characterized by a well-organized
but more active cases showed a more irregular organization with bundles and streams of highly cellular connective tissue and abundant vascularization
Prevalent findings were solitary clusters of large
often with a yellowish discoloration of the cytoplasm
small aggregates of macrophages containing dark
numerous hemorrhages and multifocal perivascular aggregates of lymphocytes were also prevalent findings
layer of the capsule most often consisted of adipose tissue
sometimes with mild perivascular infiltrates of lymphocytes
but often without any obvious inflammatory cellular response
(A) Inner surface of the implant capsule of bear BD23
a 26-years old female which had carried the implant for 2 years
Aggregates of amorphous yellowish material (asterisk) were found close to the lumen (lu) and within a layer of sparsely cellular
(B) Three-layered appearance of the implant capsule of bear W9403
a 23-years old female that had carried the implant for 3 years
The inner layer (il) consisted of partially necrotic dense and organized connective tissue
The middle layer (ml) consisted of laminar
sparsely cellular connective tissue and contained vessels and occasional hemorrhages
infiltrates of lymphocytes and aggregates of foamy
The outer layer (ol) was composed of fat cells (HE
(C) Foreign body reaction in the inner layer of the implant capsule of bear BD155
a 22-years old female that had carried the implant for 1 year
Multinucleated giant cells (arrowheads) lined the inner surface
Below were infiltrates of epitheloid and normal macrophages
proliferating vessels and some eosinophilic and neutrophilic granulocytes (HE
(D) Inner layer of the implant capsule of case 2/bear W0104
a 12-years old female that had carried the implant for 3 years
The tissue was infiltrated by large numbers of eosinophilic granulocytes (HE
Capture, handling and treatment of bears included in Cases 1–7 below, were carried out in accordance with an established protocol (20)
born in 1981 was implanted with a Telonics IMP/400/L/HP in April 1997
The implant was removed after 8 years in April 2005
The transmitter was encapsulated within the greater omentum
which was twined around its axis in a complete volvulus
so that the proximal part of the omentum formed a rope-like structure
We amputated the greater omentum involved in the twist
The capsule wall consisted of a 10–15 mm thick
and fleshy layer of connective tissue with rich vascular supply
The internal surface was irregular and yellowish
hemorrhagic and odorless fluid between the capsule and the implant
the capsule wall consisted mainly of densely woven connective tissue without any obvious organization
Foci of necrotic fat were found in some areas and small hemorrhages
moderate perivascular infiltrates of inflammatory cells
and a small number of macrophages with dark pigments
There were abundant proliferating vessels within the connective tissue
The surface of the implant had a yellowish discoloration
The inside of the plastic cylinder was covered with small
Both layers of the paper wrapping were moist and the batteries and other metal parts were corroded
but the hunter provided no information about the carcass
21.0 × 3.3 cm) and capsule from a 24-years old female bear (W8906) that had carried the device for 8 years
born in 2000 was implanted with a Telonics IMP/400/L in April 2001
The implant was removed after 5 years in April 2006
The transmitter was found in the greater omentum
abscess-like structure 5 cm in diameter was attached to one side
Both the capsule and the cystic structure contained a yellow
and odorless fluid without any recognizable distinct odor
Three culture swabs from the capsule and fluid were negative
The internal surface of the capsule wall was smooth and displayed areas of orange discoloring
but the external layer of the tissue consisted of fat
the internal part of the capsule was composed of laminar
which was diffusely infiltrated with macrophages and some neutrophilic granulocytes
The middle part consisted of dense connective tissue without any particular organization and the external layer consisted of fat infiltrated with macrophages and neutrophilic granulocytes
The blood vessels of the capsule were surrounded by mild to moderate infiltrates of lymphocytes
No other damage was observed in other parts of the implant
This bear was implanted again in April 2009
and had the implant replaced both in April 2012 and April 2015 (Telonics IMP/700 in all occasions)
No pathological changes were observed during these surgeries
and 2014 (three cubs) and was alive at den entry 2015
15.2 × 3.3 cm) and capsule with abscess-like cyst from a 6-years female bear (W0104) that had carried the device for 5 years
born in 1999 was implanted with a Telonics IMP/400/L in April 2000
The transmitter was replaced after 6 years in April 2006
encapsulated by a 1 mm thick layer of tissue that did not require amputation to remove the transmitter
The tissue had irregular whitish surfaces and a texture resembling fat
the tissue consisted of moderately vascularized
sparsely cellular adipose tissue with small
The blood vessels within this tissue were surrounded by moderate amounts of connective tissue
the wax coating of the implant had a “melted” appearance
One end cap was loose and the internal parts could not be removed without cracking the plastic shell cylinder
The paper wrappings appeared scorched and the batteries had short-circuited and were adherent to the inner surface of the plastic shell cylinder
This bear had produced litters with two cubs in 2005
15.2 × 3.3 cm) removed from a 7-years old female bear (W0010) that had carried the device for 6 years
with subsequent over-heating of the device
The wax coating had a “melted” appearance and one end cap was detached
The batteries were adherent to the inside wall of the plastic cylinder
which had to be cracked to remove the internal parts of the device
was implanted with a Telonics IMP/400/L in May 2002
The transmitter was removed after 5 years in May 2007
the author who carried out the surgery (JA)
could smell a “battery-like” odor and found that the implant was encapsulated in a 15-cm wide mass of connective tissue attached to the ventral abdominal wall cranially to the umbilicus
including the core containing the transmitter
were removed and the abdominal cavity was closed
The tissue covering the implant was firmly attached to it and had to be removed with a scalpel
Closer inspection revealed that the implant clearly had over-heated
The outside of the plastic cylinder was partly covered by a soot-like material
All internal parts of the transmitter appeared to be burned and were covered by the same soot
Both batteries had obviously been exposed to high temperatures and were partly open along the sides
The inside of the tissue that covered the implant was dark and irregular and had a “fried meat” appearance
whereas the outer surface was smooth and pale reddish
the inner surface consisted of partly necrotic
finger-like projections of connective tissue
the capsule wall consisted of connective tissue organized in a woven pattern
there were large accumulations of lipid-like
pockets of macrophages filled with yellow/brown material
and foci of calcification and mild hemorrhages
The external layer of the capsule consisted of necrotic adipose tissue with spots of yellowish discoloration
The bear had its first litter (3 cubs) the year following implantation and was legally shot in May 2009 to avoid predation of semi-domesticated reindeer in a calving area
No pathological changes were noted at necropsy
but the report focused on the trauma from three rifle shots
15.2 × 3.3 cm) removed from a 6-years old female bear (BD124) that had carried the device for 5 years
with subsequent over-heating of the device and leakage from the batteries
One end cap was detached and the outside of the implant was partly covered by a soot-like material
All internal components appeared to be burned and were covered by the same soot
was implanted with a Telonics IMP/400/L in April 2000
This bear went missing (no radio signal) in October 2002
the implant was found free-floating in the abdomen
One end cap was completely detached and a metal wire (antenna) had perforated the stomach
The cause of death was peritonitis with subsequent sepsis
The wax coating was melted at both ends of the implant
longitudinal cracks and fell into multiple pieces when the wax was removed
presumably due to short-circuiting of the batteries and subsequent over-heating
15.2 × 3.3 cm) from a female bear (W0020) found dead 10 years after implantation
due to perforation of the stomach by a metal wire (antenna) and leakage from the batteries that had short-circuited
(B) Implant with detached end cap and metal wire
(C) Implant after removal of the wax coating
showing several longitudinal cracks in the plastic cylinder
showing signs of over-heating and scorching
(E) Batteries showing signs of over-heating
born in 2001 was implanted with a Telonics IMP/400/L in May 2002
This bear went missing (no radio signal) in September 2005
except for a 10 × 15 cm opening into the abdominal cavity
The implant was located close to this opening
The bear's body condition was average and the gastrointestinal tract was empty
The pathologist concluded that death had occurred quickly
The implant was covered with a black material
and the inside of the plastic cylinder contained abundant
The plastic cylinder was cracked and the batteries had short-circuited and were leaking
Although the necropsy report was not conclusive
it is likely that leakage from the batteries caused fatal peritonitis
with possible erosion of the abdominal wall
born in 1999 was implanted with a Telonics IMP/400/L in May 2000
The implant was removed after 5 years in May 2005
The transmitter was in the greater omentum
surrounded by a 2–3 mm thick capsule with a rich vascular supply
with its root having the appearance of a twisted rope
The wall of the capsule had a smooth inner surface and an outer surface that was covered with adipose tissue
The middle layer consisted of fibrous tissue containing some gray to yellow tissue
and loosely woven tissue over a zone of necrotic debris without any obvious organization
and the external surface was covered by adipose tissue
diffuse infiltrates of neutrophilic granulocytes were present in the tissues
Some epithelioid macrophages with foamy cytoplasm were also seen
and there were multiple aggregates of yellow pigment within the capsule wall
Except for minor signs of wax wear at the ends
all parts of the implant were unremarkable
This bear was captured again in May 2008 to change the radio collar and in May 2011 to remove the radio collar
No further information about its fate after 2011 is available
15.2 × 3.3 cm) and capsule from a 6-years old female bear (BD109) that had carried the device for 5 years
We documented that Telonics intraperitoneal VHF radio transmitters had a high rate of serious technical failures
including an ineffective moisture barrier that caused corrosion of metal parts
We also documented that implants can over-heat and disintegrate
causing serious tissue trauma in one bear after 5 years and killing two other individuals after 10 and 13 years
Telonics (21) has stated that the wax coating was stable at physiological temperature of 5–50°C. However, we observed several cases of changes in the coating consistent with partial melting. The normal deep body temperatures of brown bears are 32–34°C during hibernation and 37–38°C during mid-summer (22)
The highest core body temperature we have recorded in this species
We doubt that bears can survive deep body temperatures exceeding 43–44°C and 50°C is definitely not survivable
the wax coating is either not stable up to 50°C
or the device can generate internal heat that is sufficient to melt the wax
Tissue reactions to the implant appear to have started when the device became trapped in the greater omentum
encapsulation can occur in less than a year or may never happen
Four out of eight implants removed after 1 year were encapsulated
Of the 66 implants removed after 1–3 years
30 were encapsulated and seven required amputation
nine implants were found free-floating after 6–9 years
no scientific evidence to support any of these claims and the manufacturer does not provide any advice on whether or not the implant should be removed from an instrumented animal
We found corrosion of batteries and other metal parts after only 3 years in eight implants and damage of the batteries
consistent with short-circuiting in two implants after 5 years
We also found that nearly half of the implants were encapsulated
with necrotic and inflammatory tissue reactions
This shows that the wax coating of the implant is neither an effective moisture barrier nor biocompatible
Instrumentation is thus clearly meant to be long-term and potentially lifelong in most species
the SBBRP started using Telonics implants as an alternative to collars in yearling bears and later as a back-up VHF transmitter in adults equipped with GPS-collars
our standard procedure during the past decade has been to change or remove the implants after 3–5 years
depending on the reproductive cycle of females and other considerations
Due to concerns over the poor technical quality of the implants and adverse reactions to the wax coating
the SBBRP has decided to stop using Telonics implants and all such devices carried by bears that still can be radio-tracked
these intraperitoneal radio transmitters should not be used in brown bears
We have documented how a lack of attention to biological compatibility and technical stability of implanted devices can have drastic welfare implications for study animals
We recommend that standards similar to those used in human medicine be adapted for the development and use of intraperitoneal radio transmitters in wildlife
The raw data supporting the conclusions of this manuscript will be made available by the authors
and JS: acquisition and interpretation of data; JA
and AE: surgeries and sampling; BY and KM: histopathology; JM: necropsy; JA and SB: technical inspection of transmitters; JA and BY: drafting of manuscript; JA
and JS: critical revision of manuscript and approval of submitted version
The long-term funding of the Scandinavian Brown Bear Research Project has come primarily from the Swedish Environmental Protection Agency
and the Swedish Association for Hunting and Wildlife Management
We thank two colleagues for reviewing early drafts of the manuscript
students and helicopter pilots who participated in the field work
263 from the Scandinavian Brown Bear Research Project
Failing through the cracks: Shortcomings in the collaboration between biologists and veterinarians and their consequences for wildlife
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Evans AL and Swenson JE (2018) Long-Term Safety of Intraperitoneal Radio Transmitter Implants in Brown Bears (Ursus arctos)
Received: 25 June 2018; Accepted: 20 September 2018; Published: 15 October 2018
Copyright © 2018 Arnemo, Ytrehus, Madslien, Malmsten, Brunberg, Segerström, Evans and Swenson. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
*Correspondence: Jon M. Arnemo, am9uLmFybmVtb0Bpbm4ubm8=
Too many automated requests from this network
Black bears are considered less dangerous game animals than brown bears or grizzlies — but a hunting accident this month shows that encounters can still be deadly
the Virginia Department of Wildlife Resources was notified of a hunting incident in Lunenburg County
A group of hunters were pursuing a bear when it climbed up a tree
Harvey was standing about 10 feet from the bottom of the tree
with a member of the hunting group giving him first aid until local fire and EMS arrived on the scene
Harvey was then transported by ground to a nearby hospital
“The Virginia Department of Wildlife Resources is not currently seeking any charges related to this incident,” a spokesperson told GearJunkie
Lester was “a friend to all and never met a stranger,” according to an obituary
In a tribute posted to Facebook on Dec
Harvey’s son Josh initially hoped that his father would recover from the injuries sustained in the accident
Josh and some of his dad’s “good friends” were together when the accident occurred
“A man who has never missed a day of work
A man who would give you the shirt off his back…
A man who loves the outdoors and wouldn’t miss a good hunt for nothing!”
Black bears have killed 61 people across North America since 1900, according to the North American Bear Center. And it’s estimated that less than 100 Americans are killed each year in hunting accidents, Target Tamers reported
Given that millions of Americans purchase hunting licenses every year
accidents like these are statistically very rare
a person allegedly donned a bear costume and caused a grizzly amount of damage to several luxury cars
Andrew McLemore is a staff writer at AllGear Digital
Andrew has more than 10 years of experience covering a range of beats including government
with specializations in criminal justice and investigative journalism
working for nonprofit organizations including the Texas Access to Justice Commission and Texas RioGrande Legal Aid
Andrew brings his writing experience to outdoor gear and adventures throughout the Americas
Grizzly bears (Ursus arctos horribilis) are exceptionally well suited to fill the role of apex predator
But Grizzlies are also on the Endangered Species list
and their future depends less on their natural prowess and more on whether humans give them the freedom to roam across the wilderness they need to survive
But their future seems always to swing between hope and doubt
no apex predators other than wolves evoke a greater spectrum of responses—from fear and loathing on one end to respect and admiration on the other
The grizzly bear (Ursus arctos horribilis) is the iconic species of the Greater Rockies & Mountain Forests bioregion (NA13) located in the American West subrealm in Northern America.
Grizzly bears are a subspecies of the brown bear
brown bears occur across the Northern Hemisphere
from the Mediterranean countries in Southern Europe to Scandinavian countries in Northern Europe
from Tibet to Russia (with a rare subspecies in the Gobi Desert)
The brown bears in North America are a subspecies classified Ursus arctos horribilis
Grizzly bear adults are about one to 1.2 meters at the shoulder (3-4 ft). They can weigh 110 kilograms (250 lb), as in the case of a small female in the Rocky Mountains, to about 816 kilograms (1,800 lb) in the case of very large males on the Alaska Peninsula and on Kodiak Island (where the second subspecies in North America, Ursus arctos middendorfii
Grizzly bears can sometimes be confused with black bears because Grizzlies can be black
They also have a distinctive hump above their shoulders because of the powerful muscles that evolved along with their claws for digging
Image Credit: Walt Snover from Getty Images Pro via Canva Pro
Many experts think that bears were once predominantly plains animals
and other grassland flora and fauna before humans drove them into the forests and mountains
This is consistent with historical observations that there were more grizzlies on the plains than in the mountains.
“The fundamental trait of the brown bear is not its affiliation with a particular type of environment but rather its flexibility
the brown bear is almost certainly the world's most flexible large animal
Indeed, if flexibility is a trait we share with grizzlies, it’s no surprise, for we share 80% of their DNA
Grizzlies are omnivores who rely mostly on fruits
One male was seen by a devoted observer to eat 4,000 moths in a single day
They’re also able to bring down elk and other herbivores by reaching speeds up to 64 kilometers per hour (40 mph)
Grizzlies rely on their accumulated fat stores to sustain them through winter hibernation
during which the sows (females) give birth — usually to twins — and emerge with their cubs in the spring
Image Credit: Jillian Cooper from Getty Images via Canva Pro
when Lewis and Clark started their exploratory expedition up the Missouri and across the Rockies to the Pacific
there were an estimated 50,000 grizzlies in the Lower 48
The adventurers described seeing them across the western Great Plains and the Rocky Mountains
Scientists believe California once had the highest density of grizzlies outside of Alaska
with an estimated 10,000 grizzlies throughout the state
the Golden State had one grizzly for every eleven people
As the human population grew across the American West
and American fur trappers shot them at every chance
the Spanish in California lassoed grizzlies and dragged them into corrals
where the bears were forced to fight to the death against bulls
The gold miners and pioneer settlers who followed continued to shoot
and poison the bears until the last wild grizzly in California was seen in 1924
The sport of roping California grizzly bears is dramatically illustrated in James Walker’s 1877 Cowboys Roping a Bear
an estimated 2,000 grizzlies survive in Montana
This is double the population 50 years ago before they were protected under the Endangered Species Act
But the success of their recovery has only catalyzed new threats from trophy hunters
ranchers and politicians in Montana and Wyoming who want to delist the grizzly and turn management over to the states
hunting and trapping would almost certainly be renewed
attempts to delist the grizzly have failed
partly because of coordinated opposition by Native American tribes
Grizzly bears have always been central to tribal identity and culture
A bear sculpture chipped from volcanic stone that was found in California is 7,000-8,000 years old
Most tribes had a bear dance and a bear shaman
and wearing a necklace of bear claws imbued the wearer with the power and protection of the grizzly
Sioux chairman Brandon Sazue observed that grizzlies taught the tribes “the ability for healing and curing practices
so the grizzly is perceived as the first medicine person.”
Former chairman of the Hopi Tribe in Arizona
that does impact our ceremonies in that there would not be a being
a religious icon that we would know and recognize.”
A grizzly bear cub walking free from mother bear
In response to efforts to remove the grizzly bear from the Endangered Species Act
Native American tribes sued the government in 2017
advocating for protecting and restoring grizzly populations across North America
It is the most signed treaty in tribal history
Many years in the making, a plan to rewild grizzlies back to the Northern Cascades in Washington State is nearing approval. More recently, the California Grizzly Alliance, a consortium of tribal leaders, conservationists, and scientists, has organized the recognition of the 100th anniversary of the last sighting of a wild grizzly in California, declaring “2024 the Year of the California Grizzly Bear.”
Their longer-term aspiration is to “bring the state flag back to life” by rewilding grizzlies in the state.
Scientists with the California Grizzly Alliance have completed studies on the bears’ biology and behavior in preparation for the effort
they have discovered that contrary to popular belief
California grizzlies were not the fierce carnivores of lore
They had an 80% plant-based diet that relied primarily on acorns
theirs was a very healthy Mediterranean diet
Any proposal to rewild Grizzlies brings with it heated debate
for grizzly bears can kill people—an average of two per year since 2020
But the number of deaths is relatively small considering the bears’ wide range and the hundreds of thousands of people who hunt
Most deaths could be avoided with better coexistence and avoidance protocols
we must ask: what is the loss of not having healthy populations of grizzly bears
What is the loss to ecosystems where grizzly bears
as top predators who are also avid foragers
keep flora and fauna in balance and function as seed and nutrient distributors?
Research by Dr. Suzanne Simard of the Mother Tree Network illuminates the intimate relationship among salmon
She describes how grizzlies capture salmon and sit beneath trees to eat select portions (preferring the brain
leaving carcasses that feed not only other animals and organisms
Isotope tracing shows that salmons’ nitrogen is shared far into the forest through the trees’ mycorrhizal networks
A grizzly bear roams in a wooded area near Jasper National Park
As Kris Tompkins of Tompkins Conservation expressed it so well in Time Magazine:
We must ask ourselves a more subtle yet important question: What is the spiritual loss when a vital part of an ecosystem is missing
that includes the humility that comes from sharing a landscape with a creature that requires you to remember you are not always the dominant species
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An iconic species is a charismatic and ecologically significant animal selected to represent the unique biogeographical diversity of each bioregion in One Earth's Bioregions Framework. Learn more >
The Apennine brown bear (Ursus arctos marsicanus) is a critically endangered subspecies of brown bear found mainly in the Abruzzo
Lazio and Molise National Park in central Italy
This distinct population of bear – also known as the Marsican brown bear – has been isolated for centuries
and as a result has evolved unique physical characteristics and behaviours that sets it apart from other brown bears.
human activity and genetic weaknesses now mean there are only around 50 left in the wild
putting them at serious risk of extinction
Now, a new study by the Italian Endemixit project has uncovered a potentially critical genetic flaw that could be contributing to their low survival rates – the research could also provide insights to help boost conservation efforts in the future
Using advanced computer modelling and laboratory experiments
the researchers discovered a mutation in the bears’ mitochondria
which are like tiny power plants inside cells that produce energy
This defect reduces the bears’ ability to generate energy and causes a build-up of harmful byproducts
"This mutation appears to significantly impact these bears," explains Nunzio Perta
a scientist from Marche Polytechnic University in Italy
"It's like they're constantly running on low batteries
This could make it harder for them to survive
Scientists are now looking for ways to help the bears cope with this problem
One idea is to introduce more natural foods rich in antioxidants – such as berries – into their habitat
Antioxidants can help counteract the harmful effects of the faulty mitochondria
"By understanding the molecular basis of these genetic problems
we hope to create a plan to protect these bears in their natural environment,” says Perta
"The bears are a crucial part of the very unique ecosystem that we have here in Italy.”
or Marsican brown bear (Ursus arctos marsicanus)/Getty
More wildlife stories from around the world
KATHMANDU — Researchers have discovered brown bears in a part of Nepal not previously known to host the species
prompting a call to protect this area as a bear “stronghold.”
“The bears weren’t the species we primarily set up the camera traps for,” study lead author Naresh Kusi
As part of their research, Kusi and his project team have since 2021 run a network of 61 camera traps across an area in the Limi Valley that’s half the size of London. Since then, they’ve recorded images of species never before confirmed outside Nepal’s protected areas
such as the steppe polecat (Mustela eversmanii)
Pallas’s cat (Otocolobus manul) and Eurasian lynx (Lynx lynx)
it’s the brown bear — a species found throughout the Northern Hemisphere
that it’s considered critically endangered here
Yet Kusi’s team managed to capture dozens of independent images of brown bears in their camera-trapping surveys
“Although we didn’t estimate the size of the population in Limi Valley
based on our study and other studies on brown bears
we can say that the number we currently have looks like an underestimate,” Kusi said
They snapped a higher number of images in their 2022-2023 survey than in 2021
But the next year we went there during spring,” Kusi said
adding that brown bears are known to be more active in the spring
when the snow hasn’t completely melted yet and people don’t frequent the rangelands
The researchers say the finding is significant
as it comes from a region situated between the known ranges of two brown bear subspecies: the Himalayan brown bear (U
“This suggests that the area may be a ‘contact zone’ between the two subspecies,” Kusi said
The researchers write in their study that the discovery points to “the significance of Limi Valley as a stronghold for brown bears in Nepal and underscore[s] the importance of formally protecting the currently unprotected wildlife habitats in Limi Valley.”
They add that the photographed bears appeared to have the physical characteristics of the Tibetan brown bear
including a white “collar” (also described by some researchers as a yellow “scarf”) around its neck
But a genetic analysis would be needed to confirm which subspecies they belong to — or whether they’re a hybrid of the Tibetan and Himalayan subspecies if indeed the “contact zone” hypothesis is correct
Rajan Paudel, co-author of a recent study on potential bear habitats under a changing climate in Nepal
agreed on the need for more research into that hypothesis
“Another interesting aspect to investigate is whether there are any barriers in the Limi Valley and its surroundings that could have isolated brown bear populations to the east [Tibetan] and west [Himalayan] of the valley
leading to the development of two separate subspecies,” he added
While Kusi and his team posit that their finding expands the known range of brown bears in Nepal
research by Paudel and his team suggests that in a warming world
the overall range for the animals is likely to shrink
Their study found that if the average global temperature rises on a trajectory to hit by 2.7° Celsius (4.9° Fahrenheit) by the end of the century
brown bears in Nepal will lose more than two-thirds of their current suitable habitat by 2050
“Our study further shows the importance of saving the brown bears in Limi,” Paudel said
echoing Kusi’s team’s call to protect the area
we could potentially be saving both the Himalayan and the Tibetan brown bears.”
The presence of brown bears in Nepal is as mythical as the beliefs surrounding them. Until recently, the Tibetan subspecies had never been recorded in the country. (Yet again, it was a camera-trap survey that confirmed their presence in 2022.) Bears have also been pegged as the possible origin for the enduring Yeti myth
Their presence in the Limi Valley adds to the wealth of wildlife still being uncovered in the area
The valley is located in the trans-Himalayan region
only a small portion of which lies in Nepal
a country largely situated south of the Himalayas
Research into the flora and fauna of Nepal’s trans-Himalayan region
home to iconic species such as snow leopards (Panthera uncia) and wild yaks (Bos mutus)
has been limited compared to the lower-elevation hills and plains
where better-known species such as greater one-horned rhinos (Rhinoceros unicornis) and Bengal tigers (Panthera tigris) are found
Abhaya Raj Joshi is a staff writer for Nepal at Mongabay. Find him on 𝕏 @arj272
Banner Image: A captive Tibetan brown bear with the trademark yellowish scarf-like ‘collar’ around its neck. Image by Aardwolf6886 via Flickr (CC BY-ND 2.0)
Kusi, N., Gurung, S., Lama, D. T., Pathak, S., Pant, G., Timalsina, K., & Werhahn, G. (2024). New insights into the geographical distribution of brown bears Ursus arctos in Nepal. Oryx, 1-5. doi:10.1017/S0030605324000796
Baral, R., Adhikari, B., Paudel, R. P., Kadariya, R., Subedi, N., Dhakal, B. K., … Tsubota, T. (2024). Predicting the potential habitat of bears under a changing climate in Nepal. Environmental Monitoring and Assessment, 196(11). doi:10.1007/s10661-024-13253-2
It’s no Yeti, but Tibetan brown bear’s presence in Nepal is no longer a myth
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