scholarly journals Observation of polar bear (Ursus maritimus) feeding on Svalbard reindeer (Rangifer tarandus platyrhyncus) – exceptional behaviour or upcoming trend?

2018 ◽  
Vol 8 (2) ◽  
pp. 243-248
Author(s):  
Jan Kavan
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Rangifer Tarandus ◽  
Ursus Maritimus ◽  
Svalbard Reindeer

A polar bear (Ursus maritimus) was observed feeding on Svalbard reindeer (Rangifer tarandus platyrhyncus) on September 3rd 2018 near Skansbukta, central Svalbard. A well-developed male was observed to rest nearby and feed on fresh reindeer carcass. Polar bear hunting a reindeer is rather an exceptional behaviour at present, but could become more frequent with drastic decline of sea ice and thus loss of traditional hunting areas with presence of seals – the usual prey.

scholarly journals Yes, they can: polar bears Ursus maritimus successfully hunt Svalbard reindeer Rangifer tarandus platyrhynchus

Polar Biology ◽  
2021 ◽  
Author(s):  
Lech Stempniewicz ◽  
Izabela Kulaszewicz ◽  
Jon Aars
Keyword(s):  
Polar Bear ◽  
Rangifer Tarandus ◽  
Terrestrial Ecosystem ◽  
Ice Cover ◽  
High Energy ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Attractive Potential ◽  
Polar Bears ◽  
Svalbard Reindeer

AbstractThe polar bear Ursus maritimus is one of the species most endangered by the rapidly declining sea–ice cover in the Arctic, which they use as a platform to hunt fatty, high-energy seals. In recent decades, more polar bears have been forced to remain longer on land, so their access to seals is limited. The importance of terrestrial food to polar bears is disputable, and more data are needed. Terrestrial ungulates could be an attractive substitute prey for them. Svalbard reindeer Rangifer tarandus platyrhynchus are prevalent and their distribution is completely within the range of polar bears. They constitute an attractive potential prey offering a significant energy return. Pre-2000 sources state that polar bears do not attack Svalbard reindeer. This report is the first description and documentation of the complete course of a polar bear hunt for adult reindeer in Hornsund, SW Spitsbergen, and also of the bear’s hunting behaviour and the reindeer’s response. Further, we report several other recent instances of bear–reindeer interactions in Svalbard, suggesting that polar bears now hunt reindeer more frequently than they used to. This increase in hunting is probably linked to the reduced ice cover, with bears spending more time on land, and a growing reindeer population. This study adds to earlier papers on how polar bears in Svalbard have increasingly shifted to a more terrestrial diet, and indicates that they may have an enhanced role as an apex predator in the terrestrial ecosystem.

Flagship Species – Flagship Problems: recovery of species at risk and the conservation of biodiversity in Canada1This introduction is part of the virtual symposium “Flagship Species – Flagship Problems” that deals with ecology, biodiversity and management issues, and climate impacts on species at risk and of Canadian importance, including the polar bear (Ursus maritimus), Atlantic cod (Gadus morhua), Piping Plover (Charadrius melodus), and caribou (Rangifer tarandus).

2011 ◽  
Vol 89 (5) ◽  
pp. 369-370 ◽  
Author(s):  
J. Sherman Boates ◽  
M. Brock Fenton
Keyword(s):  
At Risk ◽  
Polar Bear ◽  
Gadus Morhua ◽  
Rangifer Tarandus ◽  
Atlantic Cod ◽  
Ursus Maritimus ◽  
Flagship Species ◽  
Piping Plover ◽  
Species At Risk ◽  
Charadrius Melodus

This is an Introduction to a series of review articles, entitled Flagship Species – Flagship Problems, that identify, review, and address key problems, solutions, and contradictions linked to conservation and recovery of four iconic species at risk in Canada (polar bear, Ursus maritimus Phipps, 1774; Atlantic cod, Gadus morhua L., 1758; Piping Plover. Charadrius melodus Ord, 1824; caribou, Rangifer tarandus (L., 1758)), as well as one review article dealing with the more systemic impacts of habitat loss and degradation. The reviews are cast in the context of the broader challenge of maintaining and restoring biodiversity.

scholarly journals Testing the hypothesis that routine sea ice coverage of 3-5 mkm2 results in a greater than 30% decline in population size of polar bears (Ursus maritimus)

2017 ◽  
Author(s):  
Susan J Crockford
Keyword(s):  
Sea Ice ◽  
Population Size ◽  
Habitat Loss ◽  
Polar Bear ◽  
Population Decline ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Polar Bears ◽  
Population Declines ◽  
Sea Ice Decline

The polar bear (Ursus maritimus) was the first species to be classified as threatened with extinction based on predictions of future conditions rather than current status. These predictions were made using expert-opinion forecasts of population declines linked to modeled habitat loss – first by the International Union for the Conservation of Nature (IUCN)’s Red List in 2006, and then by the United States Fish and Wildlife Service (USFWS) in 2008 under the Endangered Species Act (ESA), based on data collected to 2005 and 2006, respectively. Both assessments predicted significant population declines of polar bears would result by mid-century as a consequence of summer sea ice extent rapidly reaching 3-5 mkm2 on a regular basis: the IUCN predicted a >30% decline in total population, while the USFWS predicted the global population would decline by 67% (including total extirpation of ten subpopulations within two vulnerable ecoregions). Biologists involved in these conservation assessments had to make several critical assumptions about how polar bears might be affected by future habitat loss, since sea ice conditions predicted to occur by 2050 had not occurred prior to 2006. However, summer sea ice declines have been much faster than expected: low ice levels not expected until mid-century (about 3-5 mkm2) have occurred regularly since 2007. Realization of predicted sea ice levels allows the ‘rapid sea ice decline = population decline’ assumption for polar bears to be treated as a testable hypothesis. Data collected between 2007 and 2015 reveal that polar bear numbers have not declined as predicted and no subpopulation has been extirpated. Several subpopulations expected to be at high risk of decline remained stable and five showed increases in population size. Another at-risk subpopulation was not counted but showed marked improvement in reproductive parameters and body condition with less summer ice. As a consequence, the hypothesis that repeated summer sea ice levels of below 5 mkm2 will cause significant population declines in polar bears is rejected, a result that indicates the ESA and IUCN judgments to list polar bears as threatened based on future risks of habitat loss were scientifically unfounded and that similar predictions for Arctic seals and walrus may be likewise flawed. The lack of a demonstrable ‘rapid sea ice decline = population decline’ relationship for polar bears also potentially invalidates updated survival model outputs that predict catastrophic population declines should the Arctic become ice-free in summer.

scholarly journals Testing the hypothesis that routine sea ice coverage of 3-5 mkm2 results in a greater than 30% decline in population size of polar bears (Ursus maritimus)

2017 ◽  
Author(s):  
Susan J Crockford
Keyword(s):  
Sea Ice ◽  
Population Size ◽  
Habitat Loss ◽  
Polar Bear ◽  
Population Decline ◽  
Ursus Maritimus ◽  
The Arctic ◽  
Polar Bears ◽  
Population Declines ◽  
Sea Ice Decline

The polar bear (Ursus maritimus) was the first species to be classified as threatened with extinction based on predictions of future conditions rather than current status. These predictions were made using expert-opinion forecasts of population declines linked to modeled habitat loss – first by the International Union for the Conservation of Nature (IUCN)’s Red List in 2006, and then by the United States Fish and Wildlife Service (USFWS) in 2008 under the Endangered Species Act (ESA), based on data collected to 2005 and 2006, respectively. Both assessments predicted significant population declines of polar bears would result by mid-century as a consequence of summer sea ice extent rapidly reaching 3-5 mkm2 on a regular basis: the IUCN predicted a >30% decline in total population, while the USFWS predicted the global population would decline by 67% (including total extirpation of ten subpopulations within two vulnerable ecoregions). Biologists involved in these conservation assessments had to make several critical assumptions about how polar bears might be affected by future habitat loss, since sea ice conditions predicted to occur by 2050 had not occurred prior to 2006. However, summer sea ice declines have been much faster than expected: low ice levels not expected until mid-century (about 3-5 mkm2) have occurred regularly since 2007. Realization of predicted sea ice levels allows the ‘rapid sea ice decline = population decline’ assumption for polar bears to be treated as a testable hypothesis. Data collected between 2007 and 2015 reveal that polar bear numbers have not declined as predicted and no subpopulation has been extirpated. Several subpopulations expected to be at high risk of decline remained stable and five showed increases in population size. Another at-risk subpopulation was not counted but showed marked improvement in reproductive parameters and body condition with less summer ice. As a consequence, the hypothesis that repeated summer sea ice levels of below 5 mkm2 will cause significant population declines in polar bears is rejected, a result that indicates the ESA and IUCN judgments to list polar bears as threatened based on future risks of habitat loss were scientifically unfounded and that similar predictions for Arctic seals and walrus may be likewise flawed. The lack of a demonstrable ‘rapid sea ice decline = population decline’ relationship for polar bears also potentially invalidates updated survival model outputs that predict catastrophic population declines should the Arctic become ice-free in summer.

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

scholarly journals Predation of Harp Seals, Pagophilus groenlandicus, by Polar Bears, Ursus maritimus, in Svalbard

ARCTIC ◽  
2019 ◽  
Vol 72 (2) ◽  
pp. 197-202 ◽  
Author(s):  
Thomas G. Smith ◽  
Ian Stirling
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Barents Sea ◽  
Population Level ◽  
Open Water ◽  
Ursus Maritimus ◽  
Polar Bears ◽  
Pagophilus Groenlandicus ◽  
Large Numbers ◽  
Pack Ice

Harp seals (Pagophilus groenlandicus) that breed in February and March in the White Sea migrate to open water around Svalbard and Franz Josef Land in the Barents Sea, feeding pelagically while following the receding ice edge northward to the edge of the polar pack. Although harp seals are present throughout the area during the summer, they are primarily pelagic and do not appear to be extensively preyed upon by polar bears (Ursus maritimus). However, occasionally, large numbers of harp seals may haul out and rest on the pack ice or feed in the water below the ice and surface to breathe between the floes. When approached by a polar bear while on the ice, harp seals do not exhibit the instant flight response characteristic of the polar bear’s primary prey species, ringed (Pusa hispida) and bearded seals (Erignathus barbatus). In this situation, polar bears may make multiple kills without either consuming their own prey or scavenging seals killed by other bears. This behavior appears not to frighten other nearby harp seals, whether hauled out on the ice or in the water below the floes. These unusual concentrations of harp seals hauled out on sea ice may be related to the distribution and abundance of fish or other epontic prey. Their lack of an escape response to predators on the surface of the sea ice is probably a result of briefly hauling out in large numbers in spring while whelping on the sea ice in areas where the consequences of potential polar bear predation are insignificant. The rare events of harp seal mortality from bears killing them on the surface of pack ice during the summer do not appear to have a significant impact at the population level of either species.

scholarly journals High contributions of sea ice derived carbon in polar bear (Ursus maritimus) tissue

PLoS ONE ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. e0191631 ◽  
Author(s):  
Thomas A. Brown ◽  
Melissa P. Galicia ◽  
Gregory W. Thiemann ◽  
Simon T. Belt ◽  
David J. Yurkowski ◽  
...  
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Ursus Maritimus

Conservation and management of Canada’s polar bears (Ursus maritimus) in a changing Arctic1This review is part of the virtual symposium “Flagship Species – Flagship Problems” that deals with ecology, biodiversity and management issues, and climate impacts on species at risk and of Canadian importance, including the polar bear (Ursus maritimus), Atlantic cod (Gadus morhua), Piping Plover (Charadrius melodus), and caribou (Rangifer tarandus).

2011 ◽  
Vol 89 (5) ◽  
pp. 371-385 ◽  
Author(s):  
E. Peacock ◽  
A.E. Derocher ◽  
G.W. Thiemann ◽  
I. Stirling
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Polar Bear ◽  
Atlantic Cod ◽  
Ursus Maritimus ◽  
Climate Impacts ◽  
Polar Bears ◽  
Charadrius Melodus ◽  
Land Claims ◽  
Conservation And Management

Canada has an important responsibility for the research, conservation, and management of polar bears ( Ursus maritimus Phipps, 1774) because the majority of polar bears in the world occur within the nation’s borders. Two fundamental and recent changes for polar bears and their conservation have arisen: (1) the ongoing and projected further decline of sea-ice habitat as a result of climate change and (2) the implementation of aboriginal land claims and treaties in Canada’s North. Science has documented empirical links between productivity of polar bear population and sea-ice change. Predictive modeling based on these data has forecast significant declines in polar bear abundance and distribution of polar bears. With the signing of northern land claims and treaties, polar bear management in Canada has integrated local aboriginal participation, values, and knowledge. The interaction of scientific and local perspectives on polar bears as they relate to harvest, climate change, and declining habitat has recently caused controversy. Some conservation, management, and research decisions have been contentious because of gaps in scientific knowledge and the polarization and politicization of the roles of the various stakeholders. With these ecological and governance transitions, there is a need to re-focus and re-direct polar bear conservation in Canada.

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