Polar bears might be worse off than we thought, study finds

Polar bears might be worse off than we thought, study finds

Polar bears might be worse off than we thought, study finds

The bear videos showed researchers all sorts of usually private aspects of polar bear life, including courtship and hunting. These trackers included accelerometers and GPS-equipped video cameras to document the bears' activities.

The five Arctic nations still need to raise more awareness about the link between the changing Arctic environment and polar bear conservation. "This study identifies the mechanisms that are driving those declines by looking at the actual energy needs of polar bears and how often they're able to catch seals".

The report, published Thursday in the journal Science, uncovers the physiological factors that have led to observed declines in polar bear populations.

"You're talking a pretty wonderful amount of mass to lose", said U.S. Geological Survey wildlife biologist Anthony Pagano, lead author of a new study in Thursday's journal Science.

Polar bears may face extinction sooner than anticipated because they may not be able to find enough food to sustain them, a new study says.

Scientists monitored nine adult female polar bears without cubs as they hunted for seals on sea ice in the Beaufort Sea, north of Canada.

The scientists also analysed blood and urine samples taken at the beginning and end of each bear's 8-11 day journey across the ice fields to ascertain the animal's metabolic rate.

Five of the nine bears studied lost body mass, indicating they were unable to catch enough prey to meet their energy demands.

"It's an issue of how much fat they can put on before the ice starts to break up, and then how much energy are they having to expend", Pagano said.

Polar bears, the apex predators of the Arctic, need more fat-reach food than previously thought, but melting sea ice in the region makes it hard for them to meet their energy needs, a new research has revealed.

A polar bear rests on a chunk of sea ice in the Arctic.

Polar bears rely nearly exclusively on a fat-rich diet of seals, which are most efficiently hunted from the surface of sea ice.

The Arctic is warming twice as rapidly as the global average, diminishing the sea ice that polar bears rely upon for food and forcing many to embark from water on to land where they desperately forage for goose eggs or rubbish from bins in far-flung towns.

"One of the reasons we started this research is because there just is not much known about the basic behaviours of these animals", Pagano said.

Previous research efforts have attempted to estimate polar bears' energy expenditures and metabolic rates based on some inferences about their physiology and behavior. As they move greater distances, they use up more energy which they find harder to replenish, for which the primary source is seals.

"These increases in movement rates and potential loss of opportunities to catch seals is going to result in a energetic imbalance for these animals, and ultimately influence their ability to provide for their cubs ... reduce cub survival and ultimately lead to population decline", Pagano said.

As the ice dwindles, "we are essentially pulling the rug out from underneath the polar bears", Durner said.

"They need to be catching a lot of seals", Anthony Pagano, a PhD candidate at UC Santa Cruz said.

The decline of Arctic sea ice amid global climate change is making polar bears travel farther to find prey such as ringed seals. A few of the bears travelled more than 155 miles (250 kilometres ) in about 10 days off the northern coast of Alaska in the Beaufort Sea, Pagano said.

It also showed that bears will spend more time moving around because of melting sea ice - which is declining at a rate of 14% per decade - and that is likely to have a negative effect on their populations.

Mr Pagano said the next step was to study what happened to polar bears throughout the year, particularly when the ice breaks up and the bears move further north with the ice.

"In the Beaufort Sea we are seeing that the ice is retreating much further to the north than it had historically", Mr Pagano said.

Related news