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normal behaviour or result of climate change?

Creator : Henry Anderson-Elliott, PhD, College of Cambridge

Just lately, scientists in Hornsund, Svalbard – a Norwegian archipelago within the Arctic ocean – witnessed a polar bear pursuing a reindeer into the ocean earlier than killing it, dragging it ashore and consuming it. The video that they captured was broadly shared on information and social media platforms. Then, two days later, they noticed the identical bear beside a second recent reindeer kill.

Their observations are the first detailed account of an entire and profitable polar bear hunt of a Svalbard reindeer. However they comply with 13 earlier reviews of polar bears preying and scavenging on reindeer on the identical archipelago between 1983 and 1999.

These are removed from the primary accounts of polar bears various their diets. Usually, within the months when the ocean is frozen, they get pleasure from a food regimen of offshore seals. However their use of supplementary meals sources within the leaner summer time months has been identified for many years, with bears gorging on seabird eggs in addition to feeding on the Churchill dump (a garbage and recycling facility) in Hudson Bay. But, related reviews of terrestrial feeding have grow to be extra frequent lately.

From stalking and chasing Canadian caribou, fishing for Arctic char and catching geese and rodents to grazing on vegetation and patrolling human refuse websites, polar bears can eat, have eaten and have tried to eat many issues.

Learn extra:
Polar bear ‘invasion’: how local weather change is making human-wildlife conflicts worse

However the viability of those onshore meals sources is uncertain as a long-term technique. Of their examine of foraging on the eider duck nests of Mitvik island, Canada, researchers discovered polar bears to be inefficient predators of seabird eggs, such that the vitality a person bear positive aspects from eggs could also be lower than beforehand thought. That’s as a result of they could use extra vitality to search out the eggs than they get from consuming them. Equally, different research have discovered that the consumption of terrestrial meals by polar bears has been inadequate to compensate for decreased searching alternatives out on the ice.

The local weather change risk

Polar bears have developed to be extremely environment friendly predators of marine mammals. They assist themselves on a fat-heavy food regimen and depend on ice-based prey, primarily ringed and bearded seals. In consequence, they’re profoundly threatened by a warming local weather.

With rising world temperatures, Arctic sea ice is melting earlier in summer time and refreezing later in winter. And because the ice-free durations grow to be longer, polar bears are spending extra time on land with out entry to their main meals.

As a consequence of local weather change, ice is melting earlier in summer time and refreezing later in winter.

Their state of affairs is being made worse by different elements, too. A latest examine discovered the vitality calls for of polar bears to be greater than beforehand assumed. With much less time on the ocean ice, and fewer seal fats to eat, polar bears will discover it harder to satisfy their vitality wants – resulting in greater loss of life charges. On the identical time, greater Arctic wind speeds could make searching seals tougher nonetheless.

Due to this fact, rising reviews of summer time scavenging, foraging and terrestrial searching are unsurprising within the context of local weather change, excessive vitality stress and the ensuing impact on their our bodies.

Burdened by publicity

The proliferation of digital platforms performs an element on this story, too. As Andrew Derocher, a professor of biology on the College of Alberta and longtime polar bear knowledgeable, defined: “Everybody has a digicam” and “‘information’ spreads quick”. He rightly identified that if the identical phenomenon was taking place within the 1950s and 1960s, nobody would possible have seen it.

Over the previous few years, images and movies of polar bears have garnered huge on-line consideration. From 56 bears besieging a Russian city, to tragic sequences of emaciated people, polar bears are getting used because the face of our local weather disaster.

Learn extra:
Within the path of the polar bears: what it is wish to be an Arctic scientist

Whereas the broad relationship right here is simple – a sea ice species can’t dwell in an above freezing future – polar bears now inhabit a world the place their each motion is seen as proof in a wider local weather change context. Amplified in our digital age, we see bears because the embodiment of our worsening world situation.

Whereas their plight is rightly delivered to our consideration, on-line content material will be misdirecting. A concentrate on particular person bears as an instance local weather points dangers shifting the burden of proof away from overwhelming scientific proof and onto the lives of single animals.

Due to this fact, observations like these in Hornsund reinforce the necessity for additional peer-reviewed analysis on the way forward for this iconic species. This single occasion shouldn’t be seen as definitive proof of shifting diets in a hotter world, however as a reminder of the spectacular creatures we stand to lose. A species whose destiny, even within the distant reaches of their Arctic panorama, is inexorably sure to our personal.


The Conversation

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