Sentences with phrase «polar bear populations as»

Not exact matches

«We are not recommending placing rhino herds in Arizona or polar bears in Antarctica,» the group writes, as, for example, the polar bear would then devastate Antarctic penguin and seal populations that have never encountered such a predator.

They concluded that, based on a median value across all scenarios, there's a high probability of a 30 percent decline in the global population of polar bears over the next three to four decades, which supports listing the species as vulnerable on the IUCN Red List.

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

Some changes are well - known, such as declines in polar bear populations and stresses to walruses being forced out of their shallow feeding grounds as ice retreats into deeper waters.

As sea ice disappears, polar bear populations will crash harder than the seabirds.

Lindqvist says that the analysis reveals that polar bear DNA has lost diversity as populations have dwindled, drifted apart and become genetically isolated, suggesting today's bears have less resilience to the environmental change, habitat loss, pollution and diseases they now face.

The population looks set to fall again as melting pack ice forces polar bears back to the land - based habitats of brown bears, where interbreeding has recently been observed.

A comprehensive review (pdf) by the US Fish and Wildlife Service concluded that shrinking sea ice is the primary cause for the decline seen in these populations, and it recently proposed listing polar bears as threatened (pdf) under the Endangered Species Act.

The likelihood of serious sea level rise under «business as usual», and impacts on water resources may not have the acute drama associated with polar bear population decline or the possibility of massive methane clathrate releases, but they are much more likely to figure on policy makers agendas — just as other long term chronic issues (such as pensions) do.

So how to explain the increase in the polar bear population from 5,000 in 1950 to 25,000 today, as documented by the U.S. Fish & Wildlife Service?

I do not want to draw any conclusions as to the threat to the polar bear populations posed by the ongoing environmental changes / future warming of the Arctic.

RE - Sanjong Thanpa: «So how to explain the increase in the polar bear population from 5,000 in 1950 to 25,000 today, as documented by the U.S. Fish & Wildlife Service?»

how to explain the increase in the polar bear population from 5,000 in 1950 to 25,000 today, as documented by the U.S. Fish & Wildlife Service?

On a related front, a new paper in the journal Nature Communications (available in full online) projects deep reductions in litter size in the polar bear population along the western shores of Hudson Bay, should the open - water season continue to lengthen as foreseen under the warming influence of accumulating greenhouse gases.

It is a very complex issue with no clear cut answers however as it is critical for polar bears to have both ice and water any reduction of sea ice is going to reduce the population over the next few decades.

WASHINGTON, Dec. 27 — The Interior Department proposed Wednesday to designate polar bears as a threatened species, saying that the accelerating loss of the Arctic ice that is the bears» hunting platform has led biologists to believe that bear populations will decline, perhaps sharply, in the coming decades.

The New York Times has come up with a new defense against so - called climate denialists who happen to point out that most polar bear populations are steady or increasing amidst climate change: The ice hasn't disappeared as fast as we said it would.

As a physical scientist rather than a biologist, I am generally reluctant to get involved in such topics as the influence of climate on polar - bear population, health and biologAs a physical scientist rather than a biologist, I am generally reluctant to get involved in such topics as the influence of climate on polar - bear population, health and biologas the influence of climate on polar - bear population, health and biology.

The recent listing of polar bears as «endangered» was based on junk science and GIGO computer models that claim manmade global warming will send the bears» record population numbers into oblivion.

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

In news that may be shocking to ClimateDepot, polar bear population is affected by non-climatological factors such as regulations on polar bear hunting, just like India's population is affected non-AIDS factors such as vaccination programs.

This too is understandable as Derocher was invested in his earlier predictions that «by the middle of this century, two - thirds of the polar bears will be gone from their current populations»

As they live further south than any other population of polar bears, the group is particularly vulnerable to the effects of climate change.

While the dramatic loss of weight has not led to a decline in the population of polar bears, that could change as a warming Arctic continues to melt away sea ice.

The presence of this warm water in the North Atlantic helps explain why Scotland has a relatively mild climate when compared to places at similar latitudes in North America such as Churchill, Manitoba — a Canadian town famous for its seasonal polar bear population.

Besides shrinking sea ice there are currently also other factors that negatively affect polar bears, such as human settlements, industrial activities, hunting, bio-accumulation of toxins, and smaller seal populations.

Secretary Salazar has so far defended the Bush - era «threatened» designation, claiming that threats to the species are only of concern in the future — notwithstanding the fact that polar bears are already drowning and starving as a result of sea - ice loss, with many populations declining.

As late April is the peak of this critical spring feeding period for most polar bear populations, this is when sea ice conditions are also critical.

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.

They provided alternate explanations for the decline of polar bear populations, such as stress from interactions with tourists, and suggested the bears could adapt to a warming climate by supplementing their diet with berries and vegetation.

Biologists have predicted for decades that as the ice disappears, polar bear populations will decline because they rely on the ice as a hunting platform.

As regards to the polar bear population, it seems to be stable at present.

Wilder presents these numbers as a basis for saying how concerned he is that a longer open - water season in the Arctic could increase the number of attacks by polar bears — and he's right, that's a valid concern now that the global population of bears is so high.