"We marked Kara last spring," said Jon Aars, a polar bear scientist with the Norwegian Polar Institute. "The transmitter stopped sending in winter."
He believes the polar bear has gone into hibernation on Franz Josef Land.
Kara – a 13-year-old female that weighs 217 kilograms and is 2.2 meters long – was originally marked on a glacier on Spitsbergen in April of last year. After the marking she continued out on Storfjorden and Edgeøya, but it was clear that she was going farther away. Before she turned west again, she passed through six time zones.
The map shows the GPS track of the polar bear female. Calculations done with the Google Maps Distance Calculator shows that from April to December of last year she traveled nearly 3,100 kilometers, mostly on the ice, but also on swims that lasted several days. The polar bear walked and swam to Severnaya Zemlya, east of the Kara Sea, before turning its nose westward again in a more northerly route to Franz Josef Land. Scientists are baffled.
"We followed it closely because it was so strange," Aars said. "I thought it was going to Franz Josef Land, but it was a bit poor with the ice there, so I think it changed his mind. So we thought it was going to Novaya Zemlya, but as it approached it turned it and went northeast. So I thought it would go on to an island called Ensomheten, not far away, but it again decided against it and went north. It also took a long time before it went on land."
This is unusual for the researchers. Over the years they have sent between 200 and 300 transmitters out in Svalbard and never before has a marked polar bear covered such a large stretch. During the early 1990s a marked polar bear went to Novaya Zemlya and there is also a case where a bear wandered from Svalbard to Greenland.
You can sett the tracks here
"We are certainly impressed just that it went to to Franz Josef Land," the polar bear researcher said.
"It says at the least that they are able to make long distances and that they have a large capacity. So it hunts along the way, it will eat steadily and I think it might have been in good hunting areas."
Both strategies work fine, Aars said, referring to bears who are more sedentary.
People who were out last summer and fall have also reported they observed much fatter bears on the ice than in Svalbard.
Kara left Severnaya Zemlya after a few days and, according to measurements from the GPS transmitter and temperature transmitter, she swam for two to three days on the way west again towards Franz Josef Land. In December, the transmitter stopped working. It is likely the polar bear has gone into hibernation, according to the researchers.
"And it's quite possible it has kids," Aars said.
But is the bear aware of where it's going?
"I think they have preferences," he said. "But it is not certain that it was a Svalbard bear. Maybe it was a Franz Josef bear?"
One of the lessons from this year's polar expedition was that there have been fewer cubs less than a year old. NRK Nordnytt first reported the news, but Aars also noted the number of bears that are labeled is small that he will be careful making a firm declaration.
"But it was striking enough that one begins to wonder whether this has been a bad year," he said. "Of the 29 females, we had three females with cubs. In normal conditions a third or more will have cubs."
The results from the expedition will be published soon. Experience shows the number of one-year-olds is normal. A female with two newborns, which Svalbardposten wrote about earlier during the winter, are not included in the registration since she is not marked. There is also a pair of females that have been hibernating and researchers know at least one has given birth.
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A total of 73 polar bears were handled this season. Researchers take measurements of all to determine growth, in addition to specific tests. The age of the bears is determined by taking a sample from a rudimentary tooth, a small tooth behind the canine teeth.
"The season was entirely pleasant," Aars said. "There was a very special relationship with the ice, which arrived very late. The ice that was in large parts of Storfjorden was thick enough to carry bears, but too thin for us to work there, so it was challenging."
The polar bear project gets financial support from WWF, which also presents information collected. This year, WWF also assisted the Norwegian Polar Institute aboard the research vessel Lance during parts of the fieldwork.
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When the satellite transmitter is drained of power, it loosens itself out and falls off the polar bear to which it is attached.
Until then, researchers can follow the bears over long periods. New and better technology allows them to receive hourly positions, along with other information such as temperature. Previously they obtained one position per year.
New bears are frequently marked for the purpose of obtaining better knowledge of their behavior and living conditions.