Imagine you need to walk through snow and ice all day for most of the year. You’d work up quite an appetite — and also get hungrier.
That sums up a polar bear’s life span.
Living in the icy Arctic, they prey on fat-rich mammals like seals that are ringed to keep themselves in this environment.
And polar bears now require more food than previously, a study found.
The iconic animals require 1.6 times more energy than Has Been estimated in the 1990s, researchers at the US Geological Survey, the Alaska Science Center in Anchorage, and at the University of California in Santa Cruz report from the journal “Science.”
“They will need to be catching a great deal of seals,” Anthony Pagano, a PhD candidate at UC Santa Cruz said.
Less sea ice makes them wander more
In total, every 10 to 12 days the bears would need to consume 19 seal pups or one ringed seal to prevent starvation, the researchers say.
They presume the bears’ appetite for meals is greater than anticipated due to a lack of sea ice; that makes the bears have to roam over greater distances to find and kill prey.
According to a research by the University of Colorado, the level of sea ice across the Arctic is diminishing at a rate of 14% per decade.
The problem is that several bears can not appear to find enough food to satisfy their high energy requirements.
Five lost weight, amounting to approximately 10 percent of their body mass throughout the eight- .
“Increases in motion (…) evidenced by the loss of sea ice habitat are likely to have negative (…) consequences on polar bear reproductive success, and ultimately, their inhabitants,” the researchers conclude.
Polar bears in a warming world
The truth is that climate change might hit on bears challenging is not a surprise.
In December this past year, a video of a dying polar bear rummaging in trash and eating styrofoam, supposed to be hungry, went viral on social networking. That bear turned out to probably have been ill.
But sea ice that is vanishing leaves the predators’ hunt for seals difficult.
It was thought that polar bears could go into a sort of walking condition when no food is about, decreasing their metabolic levels and consequently their energy demands. This premise was found not to be true.
“Two-thirds of the planet’s polar bears could perish out by 2050,” warns WWF, demanding an instantaneous reduction in greenhouse gas emissions so the bears could stand a chance of survival.
According to the International Union for Conservation of Nature, there are roughly bears left. The species is categorized as “vulnerable” At the U.S., it’s considered a threatened species. ”
IUCN experts estimate that the inhabitants could reduce by 30 to 50% when the loss of sea ice continues.
Observing bears’ hunting successes close up
Did Pagano and his coworkers prove that it’s harder for bears to locate food at a planet with less sea ice? The researchers noticed that the bears and went there.
“We have been recording declines in polar bear survival rates, body condition, and population numbers over the past decade,” Pagano said. “This study explains the mechanisms that are driving those declines by looking at the actual energy demands of polar bears and how often they are in a position to catch seals.”
They observed the bears over three years for discreet time periods and collared nine adult female polar bears with a GPS video camera around the sea ice of the Beaufort Sea in Alaska.
They were told the distances the bears wandered by the GPS, and the camera captured if the bears were effective in eating and killing prey.
To assess the animals’ energy needs, the investigators injected them with a tracable (nonradioactive) component.
By assessing the bears’ blood samples before and afterwards, they could figure out the amount of carbon dioxide consequently its rate, and which the creature had generated.
“An increasing proportion of bears are unable to satisfy their energy requirements,” the authors concluded.
While the recent study may be bad news, it does not automatically mean that the end to polar bears, comments Jörns Fickel, a evolution geneticist at the Leibniz seminar for Zoo and Wildlife Research in Berlin.
“nobody can conclude from the analysis that polar bears will get extinct,” he informs DW. “I am still optimistic that the species will create it.”
From an evolutionary perspective, a reduction in body fat in certain animals does not automatically mean that the amount of polar bears will probably decline, Fickel stresses.
“In a population, there are always individuals who cope better or worse without any modifications.”
Polar bears are creatures that are evolutionary: the species evolved as some 600,000 decades.
Fickel points out that the species has seen many periods and that they may be able to adjust to a warmer globe — as long as a seal people is, that is.
But still, “when I see images of large canning blocks breaking off and the sea ice is retreating, I get worried,” Fickel admits.
As a scientist, he stresses that we shouldn’t move off of gut feelings, but rather reliable data — “and for polar bears, people (data) aren’t there yet.”
So don’t give up on the powerful bear.