scholarly journals Extralimital Sighting of a Polar Bear, Ursus maritimus, in Northeast Saskatchewan

2003 ◽  
Vol 117 (4) ◽  
pp. 648 ◽  
Author(s):  
Michael A. Goodyear
Keyword(s):  
Body Fat ◽  
Adult Male ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
Hudson Bay ◽  
Western Coast ◽  
Break Up

The first documented occurrence of a Polar Bear (Ursus maritimus) in northeastern Saskatchewan, 420 km from the western coast of Hudson Bay, is described. The bear was most likely a sub-adult male in fair condition, with respect to body fat. Early break-up of ice on Hudson Bay in the spring of 1999 may have contributed to this significant extralimital sighting.

The Present Status of the Polar Bear in the James Bay and Belcher Islands Area, by Charles Jonkel, Pauline Smith, Ian Stirling & George B. Kolenosky. Canadian Wildlife Service, Occasional Paper No. 26, 42 pp., figs & tables, 22.9 × 16.4 × 0.4 cm, paperbound [no price indicated], 1976. - The Ecology of the Polar Bear (Ursus maritimus) along the Western Coast of Hudson Bay, by Ian Stirling, Charles Jonkel, Pauline Smith, Richard Robertson & Dale Cross. Canadian Wildlife Service, Occasional Paper No. 33, 64 pp., figs & tables, 28.5 × 16.5 × 0.5 cm, paperbound [no price indicated], 1977. - Dynamics of Snowshoe Hare Populations in the Maritime Provinces, by Thomas J. Wood & Stanley A. Munroe. (Canadian Wildlife Service, Occasionel Paper Number 30.) Minister of Supply and Services, Ottawa, Canada: 21 pp., figs & tables, 23 × 16 × 0.2 cm, paper cover [no price indicated], 1977. - Peary Caribou and Muskoxen on Western Queen Elizabeth Islands, NWT, 1972–74, by F. L. Miller, R. H. Russell & Anne Gunn. (Canadian Wildlife Service Report Series No. 40.) Printing and Publishing, Supply & ServicesCanada, Ottawa, Canada: 55 pp., figs & tables, 28 × 21.5 × 0.5 cm, stiff paper cover, Can. $ 4.00, 1977.

1979 ◽  
Vol 6 (3) ◽  
pp. 249-250
Author(s):  
J. F. D. Frazer
Keyword(s):  
Present Status ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
Snowshoe Hare ◽  
Hudson Bay ◽  
Western Coast ◽  
James Bay ◽  
Maritime Provinces ◽  
Paper Cover ◽  
Canadian Wildlife

scholarly journals Excavation of an Arctic Fox, Alopex lagopus, den by a Polar Bear, Ursus maritimus

2004 ◽  
Vol 118 (4) ◽  
pp. 602
Author(s):  
Evan S. Richardson ◽  
Ryan K. Brook
Keyword(s):  
National Park ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
Hudson Bay ◽  
Arctic Fox ◽  
Alopex Lagopus ◽  
N 93

We observed a Polar Bear (Ursus maritimus) excavating an Arctic Fox (Alopex lagopus) den on 24 June 1998, 3 km inland from the Hudson Bay coast (58°40'N, 93°12'W), near Cape Churchill in Wapusk National Park, Manitoba. To our knowledge this is the first observed excavation of an Arctic Fox den by a Polar Bear.

An observation of possible cannibalism by polar bears (Ursus maritimus)

1985 ◽  
Vol 63 (6) ◽  
pp. 1516-1517 ◽  
Author(s):  
N. J. Lunn ◽  
G. B. Stenhouse
Keyword(s):  
Adult Female ◽  
Adult Male ◽  
Physical Condition ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Ecological Significance ◽  
Natural Conditions ◽  
Old Adult

We observed a case of cannibalism by a 23-year-old adult male polar bear in very poor physical condition on Southampton Island, N.W.T. It had apparently killed an adult female and was feeding on the carcass. Cannibalism among polar bears does occur under natural conditions. It is difficult to document how often this occurs and of what ecological significance it might be.

Movement of a female polar bear (Ursus maritimus) in the Kara Sea during the summer sea-ice break-up

2017 ◽  
Vol 472 (1) ◽  
pp. 17-20 ◽  
Author(s):  
V. V. Rozhnov ◽  
N. G. Platonov ◽  
S. V. Naidenko ◽  
I. N. Mordvintsev ◽  
E. A. Ivanov
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
Kara Sea ◽  
Female Polar Bear ◽  
Break Up

Polar bear (Ursus maritimus) maternity denning habitat in western Hudson Bay: a bottom-up approach to resource selection functions

2005 ◽  
Vol 83 (6) ◽  
pp. 860-870 ◽  
Author(s):  
Evan Richardson ◽  
Ian Stirling ◽  
David S Hik
Keyword(s):  
Resource Selection ◽  
Polar Bear ◽  
Vegetation Index ◽  
Landsat Imagery ◽  
Ursus Maritimus ◽  
Habitat Characteristics ◽  
Tree Cover ◽  
Selection Function ◽  
Hudson Bay ◽  
Western Hudson Bay

We examined habitat characteristics of 101 polar bear (Ursus maritimus Phipps, 1774) den sites and 83 adjacent unoccupied sites in western Hudson Bay, Canada, between mid-August and early October 2001 and 2002. Bears denned almost exclusively in peat banks (n = 100) along the edges of creeks, rivers, and lakes adjacent to open lichen tundra sites. Den sites differed from unoccupied sites by having greater tree cover (P = 0.002), less moss cover (P < 0.001), and less herbaceous cover (P = 0.005). The presence of tree roots improved substrate stability, providing support to den structures. Den entrance azimuths were weighted toward a southeasterly aspect (P < 0.005), away from the prevailing northwest winds. To identify habitats with the greatest relative probability of having a den, a resource selection function (RSF) model was developed using remote sensing imagery and 1245 known den locations. High normalized difference vegetation index and brightness values derived from Landsat imagery, which were in close proximity to water, corresponded well with polar bear den sites. Identification of critical denning areas through the use of RSF will provide resource managers with a valuable tool for ensuring the protection of denning habitat, and consequently female bears and their young.

scholarly journals Assessing polar bear ( Ursus maritimus ) population structure in the Hudson Bay region using SNP s

2016 ◽  
Vol 6 (23) ◽  
pp. 8474-8484 ◽  
Author(s):  
Michelle Viengkone ◽  
Andrew Edward Derocher ◽  
Evan Shaun Richardson ◽  
René Michael Malenfant ◽  
Joshua Moses Miller ◽  
...  
Keyword(s):  
Population Structure ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
Hudson Bay

Observations of aggregating behaviour in adult male polar bears (Ursus maritimus)

1990 ◽  
Vol 68 (7) ◽  
pp. 1390-1394 ◽  
Author(s):  
Andrew E. Derocher ◽  
Ian Stirling
Keyword(s):  
Adult Male ◽  
Ursus Maritimus ◽  
Hudson Bay ◽  
Polar Bears ◽  
Adult Males ◽  
Mean Size ◽  
The Mean ◽  
Competition For Food ◽  
Competition For Resources ◽  
Solitary Species

Polar bears (Ursus maritimus) are usually considered a solitary species, but between 50 and 60% of the adult male polar bears captured on land during the ice-free period in western Hudson Bay were sighted in aggregations with a mean size of 4 and a range of 2–14 individuals. The mean weight of aggregating adult males was significantly greater (approximately 60 kg) than the mean weight of nonaggregating adult males, but there were no significant differences in the mean age. Aggregations occurred throughout the ice-free period (August–October) and were most common at prominent points along the coast or nearby islands. Some locations were used over several years. The lack of competition for food and the absence of breeding activity during the ice-free period produce conditions that may facilitate aggregating. Familiarity with conspecifics may yield benefits by reducing the severity and frequency of competition for resources on the sea ice.

scholarly journals Trends in body condition in polar bears (Ursus maritimus) from the Southern Hudson Bay subpopulation in relation to changes in sea ice

2016 ◽  
Vol 2 (1) ◽  
pp. 15-32 ◽  
Author(s):  
M.E. Obbard ◽  
M.R.L. Cattet ◽  
E.J. Howe ◽  
K.R. Middel ◽  
E.J. Newton ◽  
...  
Keyword(s):  
Sea Ice ◽  
Body Condition ◽  
Survival Rates ◽  
Ursus Maritimus ◽  
Social Classes ◽  
The Arctic ◽  
Hudson Bay ◽  
Polar Bears ◽  
Western Hudson Bay ◽  
Break Up

Sea ice is declining over much of the Arctic. In Hudson Bay the ice melts completely each summer, and advances in break-up have resulted in longer ice-free seasons. Consequently, earlier break-up is implicated in declines in body condition, survival, and abundance of polar bears (Ursus maritimus Phipps, 1774) in the Western Hudson Bay (WH) subpopulation. We hypothesised that similar patterns would be evident in the neighbouring Southern Hudson Bay (SH) subpopulation. We examined trends 1980–2012 in break-up and freeze-up dates within the entire SH management unit and within smaller coastal break-up and freeze-up zones. We examined trends in body condition for 900 bears captured during 1984–1986, 2000–2005, and 2007–2009 and hypothesised that body condition would be correlated with duration of sea ice. The ice-free season in SH increased by about 30 days from 1980 to 2012. Body condition declined in all age and sex classes, but the decline was less for cubs than for other social classes. If trends towards a longer ice-free season continue in the future, further declines in body condition and survival rates are likely, and ultimately declines in abundance will occur in the SH subpopulation.

Patterns of sea ice drift and polar bear (Ursus maritimus) movement in Hudson Bay

2020 ◽  
Vol 641 ◽  
pp. 227-240
Author(s):  
NJ Klappstein ◽  
RR Togunov ◽  
JR Reimer ◽  
NJ Lunn ◽  
AE Derocher
Keyword(s):  
Energy Expenditure ◽  
Sea Ice ◽  
Body Condition ◽  
Polar Bear ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Hudson Bay ◽  
Drift Speed ◽  
Ice Drift ◽  
Sea Ice Drift

Sea ice habitats are highly dynamic, and ice drift may affect the energy expenditure of travelling animals. Several studies in the high Arctic have reported increased ice drift speeds, and consequently, polar bears Ursus maritimus in these areas expended more energy on counter-ice movement for station-keeping. However, little is known about the spatiotemporal dynamics of ice drift in Hudson Bay (HB) and its implications for the declining Western Hudson Bay (WH) polar bear subpopulation. Using sea ice drift data from 1987-2015 and polar bear satellite telemetry location data from 2004-2015, we examined trends in drift speeds in HB, polar bear movement relative to drift, and assessed annual and individual variation. In contrast to other areas of the Arctic, we did not find an increase in ice drift speed over the period examined. However, variability in ice drift speed increased over time, which suggests reduced habitat predictability. Polar bear movement direction was not strongly counter to ice drift in any month, and ice drift speed and direction had little effect on bear movement rates and, thus, energy expenditure. On an annual scale, we found individuals varied in their exposure and response to ice drift, which may contribute to variability in body condition. However, the lack of a long-term increase in ice drift speed suggests this is unlikely to be the main factor affecting the body condition decline observed in the WH subpopulation. Our results contrast findings in other subpopulations and demonstrate the need for subpopulation-specific research and risk evaluation.

Seasonal and annual movement patterns of polar bears on the sea ice of Hudson Bay

2006 ◽  
Vol 84 (9) ◽  
pp. 1281-1294 ◽  
Author(s):  
E.K. Parks ◽  
A.E. Derocher ◽  
N.J. Lunn
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Movement Patterns ◽  
Temporal Changes ◽  
Reproductive Status ◽  
Energy Output ◽  
Hudson Bay ◽  
Polar Bears ◽  
Western Hudson Bay ◽  
Break Up

Polar bears ( Ursus maritimus Phipps, 1774) move thousands of kilometres over sea ice searching for mates and hunting for seals, which are their primary prey. Recently, decreased sea ice extent and earlier ice break-up have been linked to shifts in seal distribution and abundance and to declines in polar bear condition and numbers in the western Hudson Bay polar bear population. We used geographic positioning system and satellite collars deployed between 1991 and 2004 to quantify movement patterns of adult female polar bears on the sea ice of Hudson Bay in relation to reproductive class and temporal variations in sea ice patterns. We tested whether reproductive status and season affected movement and whether temporal changes in movement were correlated with temporal changes in sea ice patterns in Hudson Bay. Movement patterns were not dependent on reproductive status but did change significantly with season. Annual distances moved and areas covered by bears in Hudson Bay have decreased since 1991, which suggests that measured declines in bear condition and numbers are due to reduced prey intake as opposed to increased energy output. These declines in bear movement are correlated with progressively earlier ice break-up in western Hudson Bay.

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