Mild temperatures may affect Arctic wildlife: biologist

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Polar bears are one of the many Arctic species that may be affected by the milder winter weather this year. Pixabay photo

Mild temperatures this winter is a cause for concern for at least one biologist studying marine and terrestrial mammals in Nunavut.

Reduced snow levels
Wildlife biologist Jeff Higdon says reduced snow levels may cause problems for female polar bears, who need ample snow to dig dens in which they give birth. Research has shown that in important maternity denning areas, such as east Baffin Island, female bears travel to higher altitudes on hills and mountains to find adequate snow depth, stated Higdon.

A reduction in snowfall levels during early winter will potentially reduce available denning habitat for these animals, explained the wildlife biologist.

Late freeze-up
For polar bears a longer open-water season leads to more time spent on shore. This can reduce seal hunting opportunities for the bears.

Walruses who depend on sea ice as a haul out area are also affected by late freeze ups. When an icy platform is not available, walruses have to resort to haul-out areas on land.

This limits foraging opportunities for walruses, explained Hidgon.

Freezing rain
Caribou may potentially be affected by freezing rain. Past events have indicated that caribou may have disappeared and died because of freezing rain. In one extreme case, it is believed the native caribou on Nunavut’s Belcher Islands disappeared in the late 1800s when freezing rain created a layer of ice over all the lichen.

More recently, about three years ago, numerous caribou were found dead by Environment and Climate Change Canada migratory bird researchers on Prince Charles Island in Foxe Basin, Nunavut.

“It’s likely that they died of starvation due to ice cover on lichen forage,” said Higdon.

According to Dr. Stephen D. Petersen, director of conservation and research at Assiniboine Park Zoo, for polar bears, rain on snow may be detrimental. Polar bear dens may collapse, killing the moms and cubs.

However, Arctic animals adapt really well to a fair amount of variation in the weather, said Petersen. Milder weather may be an advantage for some animals since they are not using as much fat resources to keep warm. For example, muskox and caribou may not lose weight as fast.

“There will be winners and losers if the weather in Nunavut is consistently milder. For ice adapted species (ringed seals and polar bears) eventually it will put them at high risk and for other species it might be better (harbour seals and killer whales). It is really difficult to predict what will happen in the short term,” wrote Petersen.

According to hunter Max Kullak, despite the mild weather, the behaviour of animals in Arctic Bay where he lives has not been an issue.

“Hunting is still pretty much the same. Mild weather doesn’t seem to affect their (animals’) way of life and movements,” said Kullak.

 

1 COMMENT

  1. “Mild temperatures this winter is a cause for concern for at least one biologist studying marine and terrestrial mammals in Nunavut.” published 11 Jan 202 when the forecast high in Iqaluit was -27C and in Arctic Bay (also mentioned in the story), -31C.

    Meteorologically, December is still *fall* in the Arctic: a brief check of weather records for Iqualuit shows a high for Dec 30 in 2019 of -6.3C but it was -6.9C on the same day in 2016 – a negligible difference. It was -9.2C on 25 Dec 2019 but -4.6C on the same day in 2015. It was -4.0C on19 Dec 2019 but +2.0C on the same day in 2009.

    In other words, a spate of relatively ‘warm’ (i.e. still freezing) weather in December is hardly cause for the kind of handwringing demonstrated in this article.

    This is not *news* – this reporter was giving biologist Jeff Higdon an opportunity to tell scary stories with little basis in fact. For example, is Higdon suggesting there has been so little ice so far this winter (or any other winter) that Atlantic walrus have been forced to haul out on land, starving? Or is he referring to what some people, like David Attenborough, have been saying happen to Pacific walrus in the *summer*? [which turns out not to be true regardless, as US biologists have determined that recent low summer ice has not harmed walrus, there is a 2017 report]

    And just so you know, Dr. Peterson from the zoo, there hasn’t been a single documented case of ‘rain on snow’ causing a catastrophic collapse of a polar bear den killing mother and cubs. There was a single incident of heavy snow event that followed a warm spell in January 1989 in the Southern Beaufort that collapsed a maternity den and killed the inhabitants. The only documented ‘rain on snow’ event causing a den collapse happened in March 1999 but there were no polar bear deaths.

    There is no ’cause for concern’ for a bit of relatively mild late fall weather. Write the story again when it has been truly ‘mild’ (i.e. above freezing) from January to March (i.e. “winter”) – THAT would be news.

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