Polar bears take some cajoling as pen pals. First you need to find one, then sedate it and quickly give it the necessary tools before it wakes up. It’s an awkward first encounter – how many friendships do you know that start with a tranquilizer dart? – and admittedly a one-sided correspondence, but soon they’re sending messages daily.
Every morning, Jon Aars, a senior researcher at the Norwegian Polar Institute, receives a batch of emails from several female polar bears in the High Arctic, checking in and letting him know where they are. “It’s always a nice way to start the day,” he says.
Svalbard, a Norwegian archipelago north of the mainland, is an ideal place for Aars to study a section of the world’s estimated 26,000 remaining polar bears. “(There are) about 300 living in Svalbard year-round,” he explains, “if you fly for one hour, most of the time you find one.”
Each year, Aars and his colleagues at the Institute capture around 70 polar bears and fit them with a tracking collar which continuously logs movement. Once a day the collar makes a satellite call, transmitting the last 24 hours of data back to the Institute, where it lands in Aars’ inbox.
“Data from movement has been very important to understand how they react and how they might respond to climate change,” Aars explains.
These large mammals are canaries in this frigid coal mine. A warming climate means a vast amount of sea ice is melting in the region, and rising temperatures are also preventing seasonal ice – which melts and recurs annually – from forming in places it once did. Several seal species – polar bears’ main prey – rely on sea ice, Aars explains, and more often than not, where sea ice can be found, so too polar bears. But these creatures are being forced to move with the times.
“Because conditions change, (polar bears) will use more time on land and look for different options,” he explains. “They hunt reindeer, they will take more birds and eggs. We have seen that bears are in different areas than they used to be – so much further north.”
Along with the tracking collar, the Institute weighs bears and takes samples to monitor their health and diet, as well as testing for evidence of pollutants. The collar can also record body temperature, which can tell scientists if a bear has moved inside a den – an indication the animal is going to give birth.
Sea ice loss is also having an impact on where polar bears are born, says Aars: “A layer of sea ice on top of the ocean makes it possible for bears to walk long distances. Important areas that they used to go to give birth to cubs are more or less lost, because you don’t have sea ice on those islands anymore.”
Bears are now swimming as far as 200 kilometers (124 miles) to reach an island den, he adds, something they did not need to do 20 years ago.
“Polar bears are optimistic animals,” Aars says. “It seems that they are quite resistant, and they are doing quite well despite the fact that they’ve lost a lot of their habitat.” Despite the odds, Svalbard’s polar bear numbers do not appear to have decreased in the last 20 years, he says.
That may not always be the case, though. According to NASA, summer ice in the Arctic is shrinking by more than 13% each decade, and this year the National Snow and Ice Data Center (NSIDC) reported the second lowest levels of summer sea ice ever recorded. The 14 lowest levels of sea ice have all occurred in the past 14 years, according the NSIDC.
Put simply, the prognosis is not good. “You don’t find polar bears anywhere in the Arctic where you don’t have sea ice at least seasonally,” says Aars. “Change is so significant and so fast, we will reach some stage in the future where it will get much harder to be a polar bear in Svalbard.”
In the meantime, his research could reveal how to help his pen pals hold out a little longer.
“What is important for us is that all this data tells us how they will respond in the future,” he adds. “Of course, you cannot do a lot … but if you still have some sea ice, enough that they would be able to be there, then it is very important to know what else you can do to make sure those species can do as well as possible.”
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