GENETIC DIVERSITY OF MARGINAL POPULATIONS OF TWO BEARS SPECIES: BROWN BEAR URSUS ARCTOS LINNAEUS, 1758 AND ASIAN BLACK BEAR URSUS THIBETANUS G. CUVIER, 1823

2018 ◽  
Author(s):  
V. YU. GUSKOV ◽  
Keyword(s):  
Genetic Diversity ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Black Bear ◽  
Marginal Populations ◽  
Ursus Thibetanus

scholarly journals Heart rate during hyperphagia differs between two bear species

2019 ◽  
Vol 15 (1) ◽  
pp. 20180681 ◽  
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.

scholarly journals Evidence of rapid change in genetic structure and diversity during range expansion in a recovering large terrestrial carnivore

2015 ◽  
Vol 282 (1807) ◽  
pp. 20150092 ◽  
Author(s):  
Snorre B. Hagen ◽  
Alexander Kopatz ◽  
Jouni Aspi ◽  
Ilpo Kojola ◽  
Hans Geir Eiken
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Range Expansion ◽  
Ursus Arctos ◽  
Rapid Change ◽  
Natural Populations ◽  
Brown Bear ◽  
Genetic Structuring ◽  
Genetic Theory ◽  
Animal Populations

Recovery of natural populations occurs often with simultaneous or subsequent range expansions. According to population genetic theory, genetic structuring emerges at the expansion front together with decreasing genetic diversity, owing to multiple founder events. Thereupon, as the expansion proceeds and connectivity among populations is established, homogenization and a resurgence of genetic diversity are to be expected. Few studies have used a fine temporal scale combined with genetic sampling to track range expansions as they proceed in wild animal populations. As a natural experiment, the historical eradication of large terrestrial carnivores followed by their recovery and recolonization may facilitate empirical tests of these ideas. Here, using brown bear ( Ursus arctos ) as model species, we tested predictions from genetic theory of range expansion. Individuals from all over Finland were genotyped for every year between 1996 and 2010 using 12 validated autosomal microsatellite markers. A latitudinal shift of about 110 km was observed in the distribution and delineation of genetic clusters during this period. As the range expansion proceeded, we found, as theory predicts, that the degree of genetic structure decreased, and that both genetic variation and admixture increased. The genetic consequences of range expansions may first be detected after multiple generations, but we found major changes in genetic composition after just 1.5 generations, accompanied by population growth and increased migration. These rapid genetic changes suggest an ongoing concerted action of geographical and demographic expansion combined with substantial immigration of bears from Russia during the recovery of brown bears within the large ecosystem of northern Europe.

Nuclear DNA microsatellite analysis of genetic diversity and gene flow in the Scandinavian brown bear (Ursus arctos)

2000 ◽  
Vol 9 (4) ◽  
pp. 421-431 ◽  
Author(s):  
Lisette Waits ◽  
Pierre Taberlet ◽  
Jon E. Swenson ◽  
Finn Sandegren ◽  
Robert Franzen
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Ursus Arctos ◽  
Nuclear Dna ◽  
Brown Bear ◽  
Microsatellite Analysis ◽  
Dna Microsatellite Analysis ◽  
Dna Microsatellite

scholarly journals Evolutionary history of enigmatic bears in the Tibetan Plateau–Himalaya region and the identity of the yeti

2017 ◽  
Vol 284 (1868) ◽  
pp. 20171804 ◽  
Author(s):  
Tianying Lan ◽  
Stephanie Gill ◽  
Eva Bellemain ◽  
Richard Bischof ◽  
Muhammad Ali Nawaz ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Dna Sequences ◽  
Evolutionary History ◽  
Ursus Arctos ◽  
Phylogenetic Analyses ◽  
Brown Bear ◽  
Preliminary Finding ◽  
Black Bear ◽  
The Tibetan Plateau ◽  
History Of

Although anecdotally associated with local bears ( Ursus arctos and U. thibetanus ), the exact identity of ‘hominid’-like creatures important to folklore and mythology in the Tibetan Plateau–Himalaya region is still surrounded by mystery. Recently, two purported yeti samples from the Himalayas showed genetic affinity with an ancient polar bear, suggesting they may be from previously unrecognized, possibly hybrid, bear species, but this preliminary finding has been under question. We conducted a comprehensive genetic survey of field-collected and museum specimens to explore their identity and ultimately infer the evolutionary history of bears in the region. Phylogenetic analyses of mitochondrial DNA sequences determined clade affinities of the purported yeti samples in this study, strongly supporting the biological basis of the yeti legend to be local, extant bears. Complete mitochondrial genomes were assembled for Himalayan brown bear ( U. a. isabellinus ) and black bear ( U. t. laniger ) for the first time. Our results demonstrate that the Himalayan brown bear is one of the first-branching clades within the brown bear lineage, while Tibetan brown bears diverged much later. The estimated times of divergence of the Tibetan Plateau and Himalayan bear lineages overlap with Middle to Late Pleistocene glaciation events, suggesting that extant bears in the region are likely descendants of populations that survived in local refugia during the Pleistocene glaciations.

scholarly journals Effects of Exposure on Genotyping Success Rates of Hair Samples from Brown and American Black Bears

2014 ◽  
Vol 6 (1) ◽  
pp. 191-198 ◽  
Author(s):  
Jeff B. Stetz ◽  
Tucker Seitz ◽  
Michael A. Sawaya
Keyword(s):  
Environmental Exposure ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Black Bear ◽  
Field Studies ◽  
Success Rates ◽  
Field Exposure ◽  
American Black Bear ◽  
Hair Samples ◽  
American Black

Abstract Noninvasively collected hair samples have been used in numerous studies to answer questions about the demographic and genetic status and trends of wildlife populations. In particular, these methods are well-suited for researching and monitoring ursid populations, which are typically difficult to study because of their rare and cryptic nature. Recently, researchers have taken increasing advantage of natural bear behaviors to obtain hair samples for genetic analyses by conducting surveys of bear rubs (objects that bears rub against such as trees and power poles). The low quality and quantity DNA in noninvasively collected samples, however, can result in low genotyping success rates, which may be exacerbated by potentially lengthy duration of environmental exposure. We investigated the effects of environmental exposure (sunlight, moisture, and duration of exposure) on genotyping success rates of brown bear Ursus arctos and American black bear Ursus americanus hair samples. We exposed a total of 238 hair samples from one brown bear and one black bear to multiple treatments for either 30-d or 60-d, periods consistent with collection intervals of recent bear rub survey projects. Sample treatments consisted of full or dappled sunlight, kept dry or saturated with water one to two times daily. We genotyped each sample at three microsatellite loci commonly used in noninvasive genetic studies of bear populations. Our results were consistent with predictions, with all three factors significantly reducing genotyping success rates. Based on our results, we recommend that the specific conditions of field exposure be considered when selecting a suite of microsatellite markers for noninvasive genetic sampling projects, and that researchers carefully consider the duration and environmental conditions that hair samples will be exposed to when designing field studies. Limiting exposure to moisture and sunlight by collecting hairs from bear rubs at relatively short intervals and selecting dry and shaded sites should reduce DNA degradation and thus result in higher genotyping success rates.

Genetic diversity of endangered brown bear (Ursus arctos) populations at the crossroads of Europe, Asia and Africa

2009 ◽  
Vol 15 (5) ◽  
pp. 742-750 ◽  
Author(s):  
Sébastien Calvignac ◽  
Sandrine Hughes ◽  
Catherine Hänni
Keyword(s):  
Genetic Diversity ◽  
Ursus Arctos ◽  
Brown Bear

Behaviour of Asiatic Black Bear (Ursus thibetanus) and Crop Damage in the Forage Corn Field

2003 ◽  
Vol 74 (3) ◽  
pp. 383-388 ◽  
Author(s):  
Yoshitaka DEGUCHI ◽  
Shusuke SATO ◽  
Kazuo SUGAWARA
Keyword(s):  
Black Bear ◽  
Crop Damage ◽  
Asiatic Black Bear ◽  
Ursus Thibetanus ◽  
Corn Field

Brown Bear (Ursus arctos) Habitat Use and Food Resources on Elmendorf Air Force Base, Alaska

2007 ◽  
Author(s):  
Sean D. Farley ◽  
Herman Griese ◽  
Rick Sinnott ◽  
Jessica Coltrane ◽  
Chris Garner ◽  
...  
Keyword(s):  
Habitat Use ◽  
Air Force ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Food Resources ◽  
Air Force Base
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