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The impact of Climate Change on Carnivorans
Topic Started: Dec 9 2017, 09:10 PM (203 Views)
Taipan
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Its not a pretty picture!

Starving Polar Bear's Last Hours Captured in Heartbreaking Video

By Stephanie Pappas, Live Science Contributor | December 8, 2017 07:12pm ET



A hard-to-watch video from Canada's Baffin Islands shows an emaciated polar bear in what were likely the last few hours of its life.

National Geographic photographer Paul Nicklen captured the sad sight on video and posted it online Dec. 5. The video shows the bear staggering toward a trash can and searching in vain for something to eat. It ends with the bear resting on the ground, exhausted.

Nicklen told National Geographic he wants the footage of the dying bear to communicate the consequences of climate change.

"When scientists say bears are going extinct, I want people to realize what it looks like. Bears are going to starve to death," Nicklen said. "This is what a starving bear looks like."

Ice-bound hunters

Polar bears depend on sea ice to hunt seals, which fuel the bears with their blubbery, energy-rich meat. As the climate warms, the Arctic has been particularly hard-hit. Arctic sea ice reaches its maximum extents in late winter, typically around March, and melts in the summer, hitting its minimums around September. In recent years, ice has been forming later, melting sooner and covering less area. Record or near-record lows in ice extent have become standard each March, when the Arctic should be at its most frosted-over.

Posted Image
Here, a polar bear stands on the island of Spitsbergen, part of the Svalbard archipelago, bordering the Arctic Ocean and the Norwegian and Greenland Seas.
Credit: Prisma Bildagentur/UIG via Getty Images

In March 2016, NASA scientist Walt Meier told Live Science that the Arctic has lost about half its volume at its maximum extents since record-keeping began. November 2017 saw an average sea-ice extent of 3.65 million square miles (9.46 million square kilometers), according to the National Snow and Ice Data Center, the third-lowest November extent on average since 1979.

For polar bears, the loss of sea ice means the loss of hunting grounds. The International Union for Conservation of Nature lists the bears (Ursus maritimus) as "vulnerable," largely because of the loss of sea ice. Already, scientists have found that the loss of ice means polar bears must swim farther for food, a fact that puts cubs, in particular, at risk. Bears must also travel longer distances on foot over sea ice as the drift of the ice increases alongside melt, according to a 2017 study by the U.S. Geological Survey. Another study of bears fitted with tracking collars near Hudson Bay found that bears now spend more time on land, arriving earlier in the summer and leaving later in the fall, a pattern that means their seal-hunting season is limited.

Though polar bears do shift their diet to snow goose eggs, caribou and other terrestrial meals when on land, a 2015 study published in the journal Frontiers in Ecology and the Environment found that the calories from these sources aren't enough to offset what the polar bears burn in foraging.

Representative bear?

Of course, there is no way to know whether any given bear would have starved without climate change, or what the history of the bear in the video is.

Shrinking sea ice is causing polar bears to starve more often, but "[y]ou can't say that any one individual is starving because of climate change," Steven Amstrup, chief scientist at Polar Bears International, told Live Science in 2015 after a heart-wrenching photo of a skeletal polar bear circulated online. That's because polar bears do starve in the wild on a regular basis. As apex predators, they have no natural enemies to put them out of their misery when they become too old or injured to hunt, Amstrup explained.

Nevertheless, Nicklen's video shows what this looks like for bears that have an increasingly hard time hanging on in warming conditions. He filmed the video with tears rolling down his cheeks, he told National Geographic.

He's been asked why he didn't do something to help, he said, but it's illegal to feed wild polar bears in Canada, and there was little he could have done even if it weren't.

"t's not like I walk around with a tranquilizer gun or 400 pounds of seal meat," Nicklen said.

https://www.livescience.com/61151-starving-polar-bear-captured-on-video.html
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Mammuthus
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I believe I posted this on the Polar bear profile, but I shall post it here as well

Polar bears shift from seals to bird eggs as Arctic ice melts
Posted Image

By Thom Hoffman

Polar bears are ditching seafood in favour of scrambled eggs, as the heat rises in the Arctic melting the sea ice. A changing coastline has made it harder for the predators to catch the seals they favour and is pushing them towards poaching goose eggs.

This is according to a team led by Charmain Hamilton of the Norwegian Polar Institute that monitored the movements of local polar bears and seals before and after a sudden decline in sea ice in 2006, which altered coastal areas in the Norwegian archipelago of Svalbard.

The researchers attached tracking devices to 60 ringed seals and 67 polar bears overall, which allowed them to compare their movements before and after the ice collapse.

Before the melt, when they were hunting on stable sea ice, the polar bears had a big advantage over their favoured prey. “Both sexes of all age classes successfully hunt seals by stalking or ‘still hunting’,” says Hamilton.

However, on a melting coastline punctuated by broken-up icebergs, the odds become stacked in the seal’s favour.

In deep water
The polar bears must now swim undetected towards the seals before launching themselves out of the water to grab their prey on the floating chunks of ice. Not all bears have mastered this explosive technique and there is a high failure rate even among those that have.

“It seems that currently, it is mainly large, male bears using this aquatic hunting method on Svalbard,” says Hamilton. “It is likely [to be] more energetically demanding than the traditional hunting methods.”
Posted Image

In response, the bears are retreating from the coast. The tracking devices show them wandering greater distances in search of alternative land-based food. The bears also spend a lot more time near bird nesting grounds, which suggests eggs have become a significant food source.

But they would need an immense omelette to replace a seal breakfast and this type of mass egg hunting can devastate nesting bird populations.

Ecologist Jouke Prop at the University of Groningen, Netherlands, is also studying geese in the Arctic. He has filmed bears devouring goose eggs at nesting sites.



Smash and grab

“It takes on average 30 seconds to locate a nest and 60 seconds to eat the eggs,” he says. Previous research found that affected bird populations can slump by up to 90 per cent.

“It is extremely intriguing how the habit of bird egg eating is developing within the polar bear population,” says Prop. “Which bears are eating eggs? Did they learn from their mothers?”

“I have seen the diarrhoea faeces of bears eating eggs,” says Maarten Loonen at the University of Groningen. “I think eggs are not their best favourite food. Too much protein. Nevertheless, they have to eat something and they probably can survive on it.”

The bears seem to be getting enough nutrition to survive, but Hamilton wonders what the long-term effects of this change in diet will be. “Seal fat is an extraordinarily rich source of lipids that will be very hard to replace,” she says.

As the bears move on to eating bird eggs for sustenance, what will happen to the geese population in the future?

“If numbers decline – which is to be expected – this will have an impact on the whole terrestrial ecosystem,” says Prop. “For example, Arctic foxes depend on young geese as food; reindeer food intake is facilitated by geese grazing the tundra.”

Despite the uncertainty, one thing is clear: the cubs and eggs of the new generation will have to adapt quickly to survive the next phase of Arctic environmental change.

https://www.newscientist.com/article/2130821-polar-bears-shift-from-seals-to-bird-eggs-as-arctic-ice-melts/
Edited by Mammuthus, Dec 10 2017, 01:41 AM.
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Taipan
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Sad video! Look at the size difference between the female Polar Bear & the Walrus!

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Satya
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Why western more worried about global worming instead us-Southern ? .. actually u would be happy as u people are living in a cold climate. :D

Anyway, Polar bears look lot skinnier than their average weight 450 kg ..hope we will get correct average weight soon!!
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