Time-dependent memory and individual variation in Arctic brown bears (Ursus arctos)

Animal movement modelling provides unique insight about how animals perceive their landscape and how this perception may influence space use. When coupled with data describing an animal's environment, ecologists can fit statistical models to location data to describe how spatial memory informs movement. We performed such an analysis on a population of brown bears (Ursus arctos) in the Canadian Arctic using a model incorporating time-dependent spatial memory patterns. Brown bear populations in the Arctic lie on the periphery of the species' range, and as a result endure harsh environmental conditions. In this kind of environment, effective use of memory to inform movement strategies could spell the difference between survival and mortality. The model we fit tests four alternate hypotheses (some incorporating memory; some not) against each other, and we found a high degree of individual variation in how brown bears used memory. We found that 52% (11 of 21) of the bears used complex, time-dependent spatial memory to inform their movement decisions. These results, coupled with existing knowledge on individual variation in the population, highlight the diversity of foraging strategies for Arctic brown bears while also displaying the inference that can be drawn from this innovative movement model.

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Use of salmon (Oncorhynchus spp.) by Brown Bears (Ursus arctos) in an Arctic, interior, montane environment

The Canadian Field-Naturalist ◽

10.22621/cfn.v133i2.2114 ◽

2019 ◽

Vol 133 (2) ◽

pp. 151 ◽

Cited By ~ 1

Author(s):

Mathew S. Sorum ◽

Kyle Joly ◽

Matthew D. Cameron

Keyword(s):

National Park ◽

Ursus Arctos ◽

Brown Bear ◽

The Arctic ◽

Brooks Range ◽

Brown Bears ◽

Arctic Circle ◽

Aerial Surveys

Salmon (Oncorhynchus spp.) is a key dietary item for temperate coastal Brown Bears (Ursus arctos) across much of their circumpolar range. Brown Bears living in Arctic, interior, and montane environments without large annual runs of salmon tend to be smaller bodied and occur at much lower densities than coastal populations. We conducted ground and aerial surveys to assess whether Brown Bears fished for salmon above the Arctic Circle, in and around Gates of the Arctic National Park and Preserve. Here, we document the use of salmon by interior Brown Bears in the Arctic mountains of the central Brooks Range of Alaska. We believe our findings could be important for understanding the breadth of the species’ diet across major biomes, as well as visitor safety in the park and Brown Bear conservation in the region.

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The smell of success: Reproductive success related to rub behavior in brown bears

PLoS ONE ◽

10.1371/journal.pone.0247964 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0247964

Author(s):

Andrea T. Morehouse ◽

Anne E. Loosen ◽

Tabitha A. Graves ◽

Mark S. Boyce

Keyword(s):

Reproductive Success ◽

Ursus Arctos ◽

Scent Marking ◽

Brown Bear ◽

Parentage Analysis ◽

Fitness Component ◽

Brown Bears ◽

Male And Female ◽

Rubbing Behavior ◽

Insight Into

Several species of bears are known to rub deliberately against trees and other objects, but little is known about why bears rub. Patterns in rubbing behavior of male and female brown bears (Ursus arctos) suggest that scent marking via rubbing functions to communicate among potential mates or competitors. Using DNA from bear hairs collected from rub objects in southwestern Alberta from 2011–2014 and existing DNA datasets from Montana and southeastern British Columbia, we determined sex and individual identity of each bear detected. Using these data, we completed a parentage analysis. From the parentage analysis and detection data, we determined the number of offspring, mates, unique rub objects where an individual was detected, and sampling occasions during which an individual was detected for each brown bear identified through our sampling methods. Using a Poisson regression, we found a positive relationship between bear rubbing behavior and reproductive success; both male and female bears with a greater number of mates and a greater number of offspring were detected at more rub objects and during more occasions. Our results suggest a fitness component to bear rubbing, indicate that rubbing is adaptive, and provide insight into a poorly understood behaviour.

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Heart rate during hyperphagia differs between two bear species

Biology Letters ◽

10.1098/rsbl.2018.0681 ◽

2019 ◽

Vol 15 (1) ◽

pp. 20180681 ◽

Cited By ~ 2

Author(s):

Boris Fuchs ◽

Koji Yamazaki ◽

Alina L. Evans ◽

Toshio Tsubota ◽

Shinsuke Koike ◽

...

Keyword(s):

Heart Rate ◽

Ursus Arctos ◽

Brown Bear ◽

Black Bear ◽

Black Bears ◽

Brown Bears ◽

Fat Reserves ◽

Generalized Additive Mixed Models ◽

Additive Mixed Models ◽

Increased Activity

Hyperphagia is a critical part of the yearly cycle of bears when they gain fat reserves before entering hibernation. We used heart rate as a proxy to compare the metabolic rate between the Asian black bear ( Ursus thibetanus ) in Japan and the Eurasian brown bear ( Ursus arctos ) in Sweden from summer into hibernation. In the hyperphagic period, black bears feed on fat- and carbohydrate-rich hard masts whereas brown bears feed on sugar-rich berries. Availability of hard masts has quantitative and spatial annual fluctuations, which might require increased activity and result in intraspecific stress. Using generalized additive mixed models we analysed the differences in heart rate between the two species. Black bears had decreased heart rates during summer but had doubled heart rate values throughout the hyperphagic period compared to brown bears. This letter illustrates the different physiological consequences of seasonal differences in food availability in two species of the same genus dealing with the same phenological challenge.

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Brown bear habitat selection in relation to anthropogenic structures in the Bieszczady Mountains, Poland

Biologia ◽

10.2478/s11756-014-0386-4 ◽

2014 ◽

Vol 69 (7) ◽

Cited By ~ 4

Author(s):

Witold Frąckowiak ◽

Jörn Theuerkauf ◽

Bartosz Pirga ◽

Roman Gula

Keyword(s):

Habitat Selection ◽

Human Factors ◽

Ursus Arctos ◽

Brown Bear ◽

Human Settlements ◽

Brown Bears ◽

Anthropogenic Structures ◽

Selection Of

AbstractIn Europe, brown bear Ursus arctos habitats frequently overlap with human settlements and infrastructure. We tested whether anthropogenic structures played an important role in habitat selection by brown bears in the Bieszczady Mountains, Poland. We analysed 668 signs of brown bear presence recorded during 6 counts along 246 km of transects (total 1,476 km) in spring, summer and autumn of 1993 and 1994. Habitat selection of bears was more related to habitat and altitude than to human factors. Avoidance of roads, settlements and forest clearings influenced habitat selection by brown bears in spring but less in summer and autumn.

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Population genetics of the main population of brown bears in southwest Asia

PeerJ ◽

10.7717/peerj.5660 ◽

2018 ◽

Vol 6 ◽

pp. e5660 ◽

Cited By ~ 1

Author(s):

Hüseyin Ambarlı ◽

Deniz Mengüllüoğlu ◽

Jörns Fickel ◽

Daniel W. Förster

Keyword(s):

Ursus Arctos ◽

Brown Bear ◽

Distribution Area ◽

Brown Bears ◽

Tissue Samples ◽

Habitat Alterations ◽

North East ◽

The North ◽

Conservation Actions ◽

Lesser Caucasus

Genetic studies of the Eurasian brown bear (Ursus arctos) have so far focused on populations from Europe and North America, although the largest distribution area of brown bears is in Asia. In this study, we reveal population genetic parameters for the brown bear population inhabiting the Grand Kaçkar Mountains (GKM) in the north east of Turkey, western Lesser Caucasus. Using both hair (N = 147) and tissue samples (N = 7) collected between 2008 and 2014, we found substantial levels of genetic variation (10 microsatellite loci). Bear samples (hair) taken from rubbing trees worked better for genotyping than those from power poles, regardless of the year collected. Genotyping also revealed that bears moved between habitat patches, despite ongoing massive habitat alterations and the creation of large water reservoirs. This population has the potential to serve as a genetic reserve for future reintroductions in the Middle East. Due to the importance of the GKM population for on-going and future conservation actions, the impacts of habitat alterations in the region ought to be minimized; e.g., by establishing green bridges or corridors over reservoirs and major roads to maintain habitat connectivity and gene flow among populations in the Lesser Caucasus.

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242 EFFECT OF SPERMATOZOA HEAD MORPHOMETRIC DIMENSIONS ON FREEZABILITY IN BROWN BEAR (URSUS ARCTOS)

Reproduction Fertility and Development ◽

10.1071/rdv19n1ab242 ◽

2007 ◽

Vol 19 (1) ◽

pp. 237 ◽

Cited By ~ 1

Author(s):

L. Anel ◽

V. Garcia-Macias ◽

F. Martinez-Pastor ◽

M. Alvarez ◽

S. Borragan ◽

...

Keyword(s):

Ursus Arctos ◽

Present Report ◽

Brown Bear ◽

High Variability ◽

Wilcoxon Test ◽

Head Size ◽

Brown Bears ◽

Recovery Rates ◽

Group A ◽

Group B

Having recently observed that survival of red deer spermatozoa after cryopreservation seemed to reflect the size of sperm heads, we hypothesized that cryoresistance of brown bear spermatozoa might also be dependent on head size, since in a preliminary study we had also observed significant differences in sperm head sizes among male brown bears (median values for area 22.2 �m2, perimeter 18.2, length 6.1 and width 4.4 �m). In the present report, we analyzed the post-thaw survival of spermatozoa of 6 brown bears that were assigned to 2 groups (3 bears/group) based on sperm size: Group A with large-size sperm heads; Group B with small-size heads. Ejaculates were obtained by electroejaculation of adult brown bears (semi-free ranging in Cabarceno Park, Cantabria, Spain) under general anesthesia (7 mg kg-1 tiletamine + zolazepan and 2 mg kg-1 ketamine). Semen was diluted (Tes-Tris-fructose, 8% glycerol, 20% egg yolk, EDTA, and Equex paste), loaded in 0.25-mL straws, and frozen in a biofreezer at 20�C min-1 to -100�C. After storage in liquid nitrogen, samples were thawed in water at 65�C for 6 s and survival was measured. Sperm motility (TM: total, and PM: progressive; %) was assessed microscopically, and sperm viability, acrosome integrity (PI/PNA-FITC), and mitochondrial status (JC-1) were assayed for fresh and thawed sperm by flow cytometry. Recovery rates (RR: thawed/fresh � 100) were calculated for all parameters. For measurement of head size, fresh sperm samples were fixed in glutaraldehyde and slides were air-dried for 2 h. The samples were then stained with Diff-Quik� staining at 37�C. The area (Ar), perimeter (P), length (L), and width (W) of the heads of >100 spermatozoa per slide were measured (Sperm Class Analyzer�; Microptic S.L., Barcelona, Spain). Data were analyzed with the SAS ver8 system, and the Wilcoxon test was applied. The respective morphometric dimensions of the 2 groups were practically identical (Ar = 22; P = 18; L = 6; W = 4). The post-thaw recovery rates of spermatozoa from Group A were: TM: 60.1 � 29.3; PM: 54.8 � 36.0; viability: 99.4 � 8.0; acrosomes: 96.2 � 3.1; mitochondria: 70.9 � 15.5. The recovery rates for Group B were: TM: 78.7 � 13.8; PM: 69.0 � 18.8; viability: 93.8 � 5.2; acrosomes: 98.2 � 9.8; mitochondria: 72.5 � 22.5. Because of the high variability of recovery rates between males within each group, there were no statistical differences between the 2 groups. The absence of differences can be explained by the small number of males examined and the high variability between them. More studies are necessary to determine whether large sperm cells of brown bears are more susceptible to damage during cryopreservation. This work was supported in part by CANTUR S.A. and CICYT (CGL 2004-0278/BOS).

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Brown bear den characteristics and selection in eastern Transylvania, Romania

Journal of Mammalogy ◽

10.1093/jmammal/gyaa047 ◽

2020 ◽

Vol 101 (4) ◽

pp. 1177-1188

Author(s):

Ulysse Faure ◽

Csaba Domokos ◽

Agathe Leriche ◽

Bogdan Cristescu

Keyword(s):

Ursus Arctos ◽

Brown Bear ◽

Habitat Characteristics ◽

The European Union ◽

Mountainous Areas ◽

Human Disturbances ◽

Brown Bears ◽

Gps Collars ◽

Maximum Entropy Modeling ◽

Open Ground

Abstract Dens are important for species that need to survive and reproduce during harsh winters. Brown bears (Ursus arctos) in Romania, listed by the European Union as a population of concern, use dens for several months each year. To date, few quantitative assessments of denning habitat have been carried out for this population or others in Europe. In 2008–2013 and 2015–2017, we used local knowledge and telemetry data from brown bears fitted with GPS collars to identify 115 winter dens and eight open ground nests used by bears in eastern Transylvania, Romania. We located most dens in mountainous areas (64%) and fewer in foothills (36%). Den entrances in mountainous areas were significantly narrower than entrances in foothills, likely due to the need for reduced thermal loss during more severe winters at higher elevations. We selected seven habitat characteristics (abiotic and biotic) and human-related covariates associated with known locations of dens and open nests to identify potential brown bear denning habitat using maximum entropy modeling. We found that terrain ruggedness was the single most important factor when predicting bear denning habitat. The habitat map derived from this study can be used in the future to safeguard bear denning areas from potential human disturbances.

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Parasitofauna of Brown Bear (Ursus arctos) in the Protected Landscape Area CHKO — Poľana

Folia Veterinaria ◽

10.1515/fv-2016-0033 ◽

2016 ◽

Vol 60 (4) ◽

pp. 20-24 ◽

Cited By ~ 1

Author(s):

T. Orosová ◽

M. Goldová ◽

J. Ciberej ◽

G. Štrkolcová

Keyword(s):

Seasonal Dynamics ◽

Dominant Species ◽

Ursus Arctos ◽

Brown Bear ◽

Young Female ◽

Brown Bears ◽

Baylisascaris Transfuga ◽

Autumn And Winter

Abstract During the years 2015—2016 we obtained 15 samples of faeces of brown bears (Ursus arctos) and 2 samples of gastrointestinal (GI) tracts of young female brown bears for helminthological examinations. The samples of faeces were collected from various sites in the protected landscape area CHKO-Poľana, and the gastrointestinal tracts originated from bears hunted down in the same area within permitted regulation of bear population for 2015. Of the 17 samples collected from the CHKO-Poľana area, 13 were positive for the presence of parasites (76.47 %). Parasitological examinations revealed the presence of 5 species of endoparasites: Eimeria, Cryptosporidium, Sarcocystis, Baylisascaris and Ancylostoma. Roundworms Baylisascaris transfuga (46.15 %) and Ancylostoma spp. (30.77 %) were the dominant species. Observation of the seasonal dynamics showed the highest prevalence of parasites during autumn and winter.

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Genetic characterization of Kenai brown bears (Ursus arctos): microsatellite and mitochondrial DNA control region variation in brown bears of the Kenai Peninsula, south central Alaska

Canadian Journal of Zoology ◽

10.1139/z08-043 ◽

2008 ◽

Vol 86 (7) ◽

pp. 756-764 ◽

Cited By ~ 12

Author(s):

J. V. Jackson ◽

S. L. Talbot ◽

S. Farley

Keyword(s):

Mitochondrial Dna ◽

Genetic Variation ◽

Control Region ◽

Ursus Arctos ◽

Brown Bear ◽

Two Phase ◽

Brown Bears ◽

Kenai Peninsula ◽

South Central ◽

Haplotypic Diversity

We collected data from 20 biparentally inherited microsatellite loci, and nucleotide sequence from the maternally inherited mitochondrial DNA (mtDNA) control region, to determine levels of genetic variation of the brown bears ( Ursus arctos L., 1758) of the Kenai Peninsula, south central Alaska. Nuclear genetic variation was similar to that observed in other Alaskan peninsular populations. We detected no significant inbreeding and found no evidence of population substructuring on the Kenai Peninsula. We observed a genetic signature of a bottleneck under the infinite alleles model (IAM), but not under the stepwise mutation model (SMM) or the two-phase model (TPM) of microsatellite mutation. Kenai brown bears have lower levels of mtDNA haplotypic diversity relative to most other brown bear populations in Alaska.

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