scholarly journals Molecular Phylogeny and SNP Variation of Polar Bears (Ursus maritimus), Brown Bears (U. arctos), and Black Bears (U. americanus) Derived from Genome Sequences

2014 ◽  
Vol 105 (3) ◽  
pp. 312-323 ◽  
Author(s):  
Matthew A. Cronin ◽  
Gonzalo Rincon ◽  
Robert W. Meredith ◽  
Michael D. MacNeil ◽  
Alma Islas-Trejo ◽  
...  
Keyword(s):  
Molecular Phylogeny ◽  
Ursus Maritimus ◽  
Black Bears ◽  
Polar Bears ◽  
Genome Sequences ◽  
Brown Bears

New insights into dietary management of polar bears ( Ursus maritimus ) and brown bears ( U. arctos )

Zoo Biology ◽  
2021 ◽  
Author(s):  
Charles T. Robbins ◽  
Troy N. Tollefson ◽  
Karyn D. Rode ◽  
Joy A. Erlenbach ◽  
Amanda J. Ardente
Keyword(s):  
Ursus Maritimus ◽  
Dietary Management ◽  
Polar Bears ◽  
Brown Bears

Trichinella and polar bears: a limited risk for humans

2017 ◽  
Vol 91 (4) ◽  
pp. 440-446 ◽  
Author(s):  
J. Dupouy-Camet ◽  
P. Bourée ◽  
H. Yera
Keyword(s):  
World War Ii ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Polar Bears ◽  
World War ◽  
Protected Species ◽  
Brown Bears ◽  
Limited Access ◽  
Human Trichinellosis

AbstractIn this review, we identified 63 cases reported since World War II of human trichinellosis linked to the consumption of parasitized polar bear (Ursus maritimus) meat. This low number contrasts to the numerous cases of human trichinellosis related to consumption of the meat of black (U. americanus) or brown bears (U. arctos). The prevalence of Trichinella infection is high in bears, but larval muscular burden is usually lower in polar bears compared to other bear species. Polar bears, therefore, seem to play a limited role in the transmission of trichinellosis to humans, as native residents living in the Arctic traditionally consume well-cooked bear meat, and travellers and foreign hunters have only limited access to this protected species due to the declining polar bear population.

scholarly journals Do Wild Polar Bears (Ursus maritimus) Use Tools When Hunting Walruses (Odobenus rosmarus)?

ARCTIC ◽  
2021 ◽  
Vol 74 (2) ◽  
pp. 175-187
Author(s):  
Ian Stirling ◽  
Kristin L. Laidre ◽  
Erik W. Born
Keyword(s):  
Food Source ◽  
Ursus Arctos ◽  
Ursus Maritimus ◽  
Ecological Knowledge ◽  
Polar Bears ◽  
Brown Bears ◽  
Direct Observations ◽  
Odobenus Rosmarus ◽  
In Captivity ◽  
In The Wild

Since the late 1700s, reports of polar bears (Ursus maritimus) using tools (i.e., pieces of ice or stones) to kill walruses (Odobenus rosmarus) have been passed on verbally to explorers and naturalists by their Inuit guides, based on local traditional ecological knowledge (TEK) as well as accounts of direct observations or interpretations of tracks in the snow made by the Inuit hunters who reported them. To assess the possibility that polar bears may occasionally use tools to hunt walruses in the wild, we summarize 1) observations described to early explorers and naturalists by Inuit hunters about polar bears using tools, 2) more recent documentation in the literature from Inuit hunters and scientists, and 3) recent observations of a polar bear in a zoo spontaneously using tools to access a novel food source. These observations and previously published experiments on brown bears (Ursus arctos) confirm that, in captivity, polar and brown bears are both capable of conceptualizing the use of a tool to obtain a food source that would otherwise not be accessible. Based on the information from all our sources, this may occasionally also have been the case in the wild. We suggest that possible tool use by polar bears in the wild is infrequent and mainly limited to hunting walruses because of their large size, difficulty to kill, and their possession of potentially lethal weapons for both their own defense and the direct attack of a predator. 

Interspecific and intraspecific mitochondrial DNA variation in North American bears (Ursus)

1991 ◽  
Vol 69 (12) ◽  
pp. 2985-2992 ◽  
Author(s):  
Matthew A. Cronin ◽  
Steven C. Amstrup ◽  
Gerald W. Garner ◽  
Ernest R. Vyse
Keyword(s):  
Mitochondrial Dna ◽  
North American ◽  
Ursus Arctos ◽  
Phylogenetic Analyses ◽  
Sequence Divergence ◽  
Black Bears ◽  
Polar Bears ◽  
Brown Bears ◽  
Dna Variation ◽  
Base Substitutions

We assessed mitochondrial DNA variation in North American black bears (Ursus americanus), brown bears (Ursus arctos), and polar bears (Ursus maritimus). Divergent mitochondrial DNA haplotypes (0.05 base substitutions per nucleotide) were identified in populations of black bears from Montana and Oregon. In contrast, very similar haplotypes occur in black bears across North America. This discordance of haplotype phylogeny and geographic distribution indicates that there has been maintenance of polymorphism and considerable gene flow throughout the history of the species. Intraspecific mitochondrial DNA sequence divergence in brown bears and polar bears is lower than in black bears. The two morphological forms of U. arctos, grizzly and coastal brown bears, are not in distinct mtDNA lineages. Interspecific comparisons indicate that brown bears and polar bears share similar mitochondrial DNA (0.023 base substitutions per nucleotide) which is quite divergent (0.078 base substitutions per nucleotide) from that of black bears. High mitochondrial DNA divergence within black bears and paraphyletic relationships of brown and polar bear mitochondrial DNA indicate that intraspecific variation across species' ranges should be considered in phylogenetic analyses of mitochondrial DNA.

An Ice Age Refugium for Large Mammals in the Alexander Archipelago, Southeastern Alaska

1996 ◽  
Vol 46 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Timothy H. Heaton ◽  
Sandra L. Talbot ◽  
Gerald F. Shields
Keyword(s):  
Black Bears ◽  
Ice Age ◽  
Polar Bears ◽  
Large Mammals ◽  
Mtdna Sequences ◽  
Brown Bears ◽  
Last Glaciation ◽  
Before And After ◽  
Alexander Archipelago

Genetic and paleontological evidence are combining to provide a new and surprising picture of mammalian biogeography in southeastern Alaska. Prior to our study, the brown and black bears of the Alexander Archipelago were considered postglacial immigrants that never had overlapping ranges. Vertebrate fossils from caves on Prince of Wales Island now demonstrate that brown and black bears coexisted there (and even inhabited the same caves) both before and after the last glaciation. Differences in mtDNA sequences suggest that living brown bears of the Alexander Archipelago comprise a distinct clade and are more closely related to polar bears than to their mainland conspecifics. We conclude that brown bears, and perhaps other large mammals, have continuously inhabited the archipelago for at least 40,000 yr and that habitable refugia were therefore available throughout the last glaciation.

Genetic relationships of North American bears (Ursus) inferred from amplified fragment length polymorphisms and mitochondrial DNA sequences

2013 ◽  
Vol 91 (9) ◽  
pp. 626-634 ◽  
Author(s):  
M.A. Cronin ◽  
M.M. McDonough ◽  
H.M. Huynh ◽  
R.J. Baker
Keyword(s):  
Mitochondrial Dna ◽  
Fragment Length ◽  
Genetic Relationships ◽  
Black Bears ◽  
Gene Pools ◽  
Polar Bears ◽  
Brown Bears ◽  
Southeast Alaska ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms

The three species of bears in North America, polar bears (Ursus maritimus Phipps, 1774), brown bears (Ursus arctos L., 1758), and black bears (Ursus americanus Pallas, 1780), have differentiated morphologies and nuclear and mitochondrial genomes. An exception is a paraphyletic mitochondrial DNA relationship and some nuclear gene lineages common to polar bears and a population of brown bears from islands in southeast Alaska. In this study, we quantified the genetic relationships of extant brown bears and black bears from Alaska and Montana, and polar bears from Alaska, with amplified fragment length polymorphisms (AFLP) and mtDNA cytochrome-b sequences. Bayesian cluster analyses of the AFLP data show each species is distinct. All brown bears, including those from the islands in southeast Alaska, cluster separately from polar bears, and black bears cluster separately from brown bears and polar bears. The mtDNA of polar bears and southeast Alaska island brown bears is paraphyletic as reported previously, but the species have different haplotypes. These data indicate that extant populations of brown bears and polar bears have separate nuclear and mitochondrial gene pools and are supported as species under the genetic species concept.

Exploring the molecular phylogeny of phasmids with whole mitochondrial genome sequences

2011 ◽  
Vol 58 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Natuo Kômoto ◽  
Kenji Yukuhiro ◽  
Kyoichiro Ueda ◽  
Shuichiro Tomita
Keyword(s):  
Mitochondrial Genome ◽  
Molecular Phylogeny ◽  
Genome Sequences

Relationships Between Plasma Levels of Organochlorines, Retinol and Thyroid Hormones from Polar Bears (Ursus maritimus) at Svalbard

2001 ◽  
Vol 62 (4) ◽  
pp. 227-241 ◽  
Author(s):  
Janneche Utne Skaare ◽  
Aksel Bernhoft ◽  
Øystein Wiig ◽  
Kaare R. Norum ◽  
Egil Haug ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Plasma Levels ◽  
Ursus Maritimus ◽  
Polar Bears
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