Microsatellite DNA and mitochondrial DNA variation in polar bears (Ursus maritimus) from the Beaufort and Chukchi seas, Alaska

2006 ◽  
Vol 84 (5) ◽  
pp. 655-660 ◽  
Author(s):  
M.A. Cronin ◽  
S.C. Amstrup ◽  
K.T. Scribner
Keyword(s):  
Mitochondrial Dna ◽  
Microsatellite Dna ◽  
Chukchi Sea ◽  
Genetic Data ◽  
Beaufort Sea ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Dna Variation ◽  
Movement Data ◽  
Mtdna Haplotype

Radiotelemetry data have shown that polar bears ( Ursus maritimus Phipps, 1774 ) occur in separate subpopulations in the Chukchi Sea and the southern Beaufort Sea. However, segregation is not absolute, and there is overlap of ranges of animals in each subpopulation. We used genetic variation at eight microsatellite DNA loci and mitochondrial DNA (mtDNA) to further assess the degree of spatial structure of polar bears from the Chukchi and southern Beaufort seas. Microsatellite allele frequencies and mtDNA haplotype frequencies of bears from the southern Beaufort and Chukchi seas did not differ significantly. Lack of differentiation at both maternally inherited mtDNA and bi-parentally inherited microsatellite loci suggests that gene flow between the two areas is mediated by both sexes. The genetic data indicate that polar bears in the southern Beaufort and Chukchi seas compose one interbreeding population. However, there is considerable fidelity to ranges in each area, particularly by adult females. The combined genetic and movement data suggest that polar bears could be managed as Beaufort Sea and Chukchi Sea subpopulations of a combined southern Beaufort Sea and Chukchi Sea population.

Phylogeography of Mitochondrial DNA Variation in Brown Bears and Polar Bears

2000 ◽  
Vol 15 (2) ◽  
pp. 319-326 ◽  
Author(s):  
Gerald F. Shields ◽  
Deborah Adams ◽  
Gerald Garner ◽  
Martine Labelle ◽  
Jacy Pietsch ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Polar Bears ◽  
Brown Bears ◽  
Dna Variation

Climate-associated drivers of plasma cytokines and contaminant concentrations in Beaufort Sea polar bears (Ursus maritimus)

2020 ◽  
Vol 745 ◽  
pp. 140978
Author(s):  
Jennifer Bourque ◽  
Jean-Pierre Desforges ◽  
Milton Levin ◽  
Todd C. Atwood ◽  
Christian Sonne ◽  
...  
Keyword(s):  
Beaufort Sea ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Plasma Cytokines

scholarly journals Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water

2012 ◽  
Vol 90 (5) ◽  
pp. 663-676 ◽  
Author(s):  
A.M. Pagano ◽  
G.M. Durner ◽  
S.C. Amstrup ◽  
K.S. Simac ◽  
G.S. York
Keyword(s):  
Sea Ice ◽  
Adult Female ◽  
Open Water ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Long Distance ◽  
Gps Collars ◽  
Movement Data ◽  
Global Positioning ◽  
Ice Conditions

Polar bears ( Ursus maritimus Phipps, 1774) depend on sea ice for catching marine mammal prey. Recent sea-ice declines have been linked to reductions in body condition, survival, and population size. Reduced foraging opportunity is hypothesized to be the primary cause of sea-ice-linked declines, but the costs of travel through a deteriorated sea-ice environment also may be a factor. We used movement data from 52 adult female polar bears wearing Global Positioning System (GPS) collars, including some with dependent young, to document long-distance swimming (>50 km) by polar bears in the southern Beaufort and Chukchi seas. During 6 years (2004–2009), we identified 50 long-distance swims by 20 bears. Swim duration and distance ranged from 0.7 to 9.7 days (mean = 3.4 days) and 53.7 to 687.1 km (mean = 154.2 km), respectively. Frequency of swimming appeared to increase over the course of the study. We show that adult female polar bears and their cubs are capable of swimming long distances during periods when extensive areas of open water are present. However, long-distance swimming appears to have higher energetic demands than moving over sea ice. Our observations suggest long-distance swimming is a behavioral response to declining summer sea-ice conditions.

Summer refugia of polar bears (Ursus maritimus) in the southern Beaufort Sea

Polar Biology ◽  
2016 ◽  
Vol 40 (4) ◽  
pp. 753-763 ◽  
Author(s):  
Jodie D. Pongracz ◽  
Andrew E. Derocher
Keyword(s):  
Beaufort Sea ◽  
Ursus Maritimus ◽  
Polar Bears

PREVALENCE AND SPATIO-TEMPORAL VARIATION OF AN ALOPECIA SYNDROME IN POLAR BEARS (URSUS MARITIMUS) OF THE SOUTHERN BEAUFORT SEA

2015 ◽  
Vol 51 (1) ◽  
pp. 48-59 ◽  
Author(s):  
Todd Atwood ◽  
Elizabeth Peacock ◽  
Kathy Burek-Huntington ◽  
Valerie Shearn-Bochsler ◽  
Barbara Bodenstein ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Beaufort Sea ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Spatio Temporal

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.

Geographic variation of PCB congeners in polar bears (Ursus maritimus) from Svalbard east to the Chukchi Sea

Polar Biology ◽  
2001 ◽  
Vol 24 (4) ◽  
pp. 231-238 ◽  
Author(s):  
M. Andersen ◽  
E. Lie ◽  
A.E. Derocher ◽  
S.E. Belikov ◽  
A. Bernhoft ◽  
...  
Keyword(s):  
Geographic Variation ◽  
Chukchi Sea ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Pcb Congeners

scholarly journals Polar Bear (Ursus maritimus) Behavior near Icebreaker Operations in the Chukchi Sea, 1991

ARCTIC ◽  
2016 ◽  
Vol 69 (2) ◽  
Author(s):  
Mari A. Smultea ◽  
Jay Brueggeman ◽  
Frances Robertson ◽  
Dagmar Fertl ◽  
Cathy Bacon ◽  
...  
Keyword(s):  
Climate Change ◽  
Human Activity ◽  
Polar Bear ◽  
Chukchi Sea ◽  
Group Behavior ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Polar Bears ◽  
Running Away ◽  
Significant Difference

Increasing interactions of polar bears (Ursus maritimus) with human activity, combined with impacts of climate change, are of critical concern for the conservation of the species. Our study quantifies and describes initial reactions and behaviors of polar bears observed from an icebreaker during summer 1991 at two exploratory drilling sites (near sites drilled in 2015) located in the Chukchi Sea 175 km and 312 km west of Barrow, Alaska. Polar bear behavior was described using continuous sampling of six predetermined focal group behavior states (walking, running, swimming, resting, feeding or foraging, unknown) and six behavioral reaction events (no reaction, walking away, running away, approaching, vigilance [i.e., watching], unknown). Forty-six bears in 34 groups were monitored from the Robert LeMeur (an Arctic Class 3 icebreaker) for periods of five minutes to 16.1 hours. Significantly more bear groups reacted to icebreaker presence (79%) than not (21%), but no relationship was found between their reactions and distance to or activity of the icebreaker. Reactions were generally brief; vigilance was the most commonly observed reaction, followed by walking or running away for short (< 5 minutes) periods and distances (< 500 m). Eleven percent of bear groups approached the vessel. No significant difference was found between reactions when cubs were present and those when cubs were absent. Despite the limited sample sizes, these findings are relevant to assessing potential impacts of resource development and shipping activities on polar bears, especially given the sparsity of such information in the face of growing human activity in the Arctic offshore areas. Overall, climate change is leading to longer and more extensive open-water seasons in the Arctic and therefore to increasing marine traffic—more vessels (including icebreakers) for a longer time each year over a wider area. 

scholarly journals Genetic Variation, Relatedness, and Effective Population Size of Polar Bears (Ursus maritimus) in the southern Beaufort Sea, Alaska

2009 ◽  
Vol 100 (6) ◽  
pp. 681-690 ◽  
Author(s):  
Matthew A. Cronin ◽  
Steven C. Amstrup ◽  
Sandra L. Talbot ◽  
George K. Sage ◽  
Kristin S. Amstrup
Keyword(s):  
Genetic Variation ◽  
Population Size ◽  
Effective Population Size ◽  
Beaufort Sea ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Effective Population
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