Survival against the odds

Since 2003, WWF has partnered with the Norwegian Polar Institute (NPI) to  track Svalbard polar bears by satellite.  The Arctic is warming twice as fast as the rest of the world, rapidly altering the sea ice that polar bears depend upon. This research helps scientists understand how polar bears are adapting to changing ice conditions. NPI conducts field research each April. This winter’s stunningly warm temperatures and low ice levels around Svalbard already appear to be having an effect on the resident bears. Jon Aars, a polar bear biologist with NPI, shares his stories and photos from the field:

April 5 2016 – Today we are working in the northern part of Spitsbergen, the main island in the Svalbard archipelago, operating from the research vessel RV Lance. After a good breakfast, we are ready to take off in our small helicopter to look for bears in the area. Woodfjorden is an area surrounded by high mountains and a side fjord with glacier fronts. It is sunny and not too cold, the wind is only moderate. Conditions are good. There are almost always some bears in this area.

A bit after 11am, we encounter a female with a cub of the year. Although this is not one of the main denning areas in Svalbard, a few females use it to den and come out with cubs every spring. Bears in this area are very local; most bears we encounter in these northern fjords tend to be recaptures earlier marked in the same area.

When we have darted the mother and check her, we do see that she is one of the locals, and a quite special bear. On Svalbard, cubs are usually weaned from their mothers when they are a little over two years old. But we first captured this bear alone in 2005 when she was only one year old. What happened? She had a large wound on her nose, and we speculated a male had forced her away from her mother in an attempt to mate. We did not expect her to survive alone, but she did. And now, at the age of 12, she has her own cub. She never grew very large, however. Although she was able to give birth, will she be able to raise her cub successfully?

This female never grew very large because she was separated from her mother a year too early. However, she’s finally become a mother herself. Magnus Andersen at NPI is taking a picture of the family. Photo: Jon Aars / NPI

After noon we caught another couple, a female together with a five year old male. Both were recaptures of bears marked as cubs in the area. It turned out they had the same mother, so if they successfully mate, it will be close inbreeding, a rare event in Svalbard despite many close relatives living in the same areas.

Close inbreeding seems, based on genetic studies from the area, to be very rare in Svalbard. However, here a sister-brother pair (likely half-siblings as they were born in different years) was caught together. If the female has cubs next year, it will be possible to establish by genetics if the two mated successfully. Photo: Jon Aars / NPI