Sentences with phrase «studied polar bear populations»

Linda Gormezano, a biologist at the American Museum of Natural History, has been studying the polar bear population along the western shore of Hudson Bay.

Not exact matches

A new University of Washington study, with funding and satellite data from NASA and other agencies, finds a trend toward earlier sea ice melt in the spring and later ice growth in the fall across all 19 polar bear populations, which can negatively impact the feeding and breeding capabilities of the bears.

In this study, scientists evaluated high - resolution satellite imagery to track the distribution and abundance of polar bears on a small island in northern Canada in an attempt to develop a tool to monitor these difficult to reach populations.

«It is possible that Svalbard may have provided one such important refuge during warming periods, in which small polar bear populations survived and from which founder populations expanded during cooler periods,» argues biologist Charlotte Lundqvist of the University at Buffalo, The State University of New York, who is a co-author of the new study.

«When we look forward several decades, climate models predict such profound loss of Arctic sea ice that there's little doubt this will negatively affect polar bears throughout much of their range, because of their critical dependence on sea ice,» said Kristin Laidre, a researcher at the University of Washington's Polar Science Center in Seattle and co-author of a study on projections of the global polar bear population.

The earlier study also compared shark population numbers with other apex predators, such as polar bears and killer whales.

The study, published in a recent issue of the journal Ecography, was accomplished using satellite - linked telemetry - tracked populations of polar bears in the Beaufort Sea and Hudson Bay.

For the real story on polar bear populations, see Federal studies show polar bear, walrus populations in trouble.

The group said that in Canada, home to two - thirds of the world's polar bears, population studies have been so sporadic that there is no reliable way to track trends.

Steven C. Amstrup, the federal biologist who led an analysis last year concluding that the world's polar bear population could shrink two thirds by 2050 under moderate projections for retreating summer sea ice, is once again in the field along Alaska's Arctic coast, studying this year's brood of cubs, yearlings and mothers.

Based on studies of radio - collared polar bears of the Beaufort Sea population between 1981 and 2000, 53 dens were located on the mainland coast of Alaska and Canada.

* Monitor polar bear populations and trends * Study polar bear feeding ecology * Work cooperatively with the Alaska Nanuuq Commission and the North Slope Borough for co-management of polar bears in Alaska * Provide technical assistance to the participants of the 1988 North Slope Borough Inuvialuit (In new vee al u it) Game Council Agreement for the conservation of polar bears in the southern Beaufort Sea region and monitor the effects of oil and gas operations in the Beaufort Sea region.

A bit more good news about polar bear populations, this time from an abundance study in the Southern Beaufort Sea.

I believed that claims about polar bear population declines were based on polar bear population studies.

Overall, and based on actual population studies, there is good evidence that polar bear numbers have increased, as Lawson said.

I didn't want to get too deeply into the analysis of polar bear population studies.

Models, not population studies are what see peril for polar bears.

Polar bears are one of the most sensitive Arctic marine mammals to climate warming because they spend most of their lives on sea ice.35 Declining sea ice in northern Alaska is associated with smaller bears, probably because of less successful hunting of seals, which are themselves ice - dependent and so are projected to decline with diminishing ice and snow cover.36, 37,38,39 Although bears can give birth to cubs on sea ice, increasing numbers of female bears now come ashore in Alaska in the summer and fall40 and den on land.41 In Hudson Bay, Canada, the most studied population in the Arctic, sea ice is now absent for three weeks longer than just a few decades ago, resulting in less body fat, reduced survival of both the youngest and oldest bears, 42 and a population now estimated to be in decline43 and projected to be in jeopardy.44 Similar polar bear population declines are projected for the Beaufort Sea region.45

Analysis of movement data from mark - recapture studies and tracking of adult female bears with satellite radio collars indicated that there are two populations of polar bears in the area, one that inhabits the west coast of Banks Island and Amundsen Gulf and a second that is resident along the mainland coast from about Baillie Islands in Canada to approximately Icy Cape in Alaska.

Based on such studies Dr. Derocher, chairman of the IUCN's Polar Bear Specialist Group (PBSG) warned, «It's clear from the research that's been done by myself and colleagues around the world that we're projecting that, by the middle of this century, two - thirds of the polar bears will be gone from their current populations».

The BioScience study also analyzed the arguments made by 45 science - based blogs about the impacts of global warming on polar bear populations.

This genome would not only provide excellent markers to study extant polar bear populations but could also provide clues as to how polar bears rapidly evolved and subsequently survived through the last interglacial period.