DNA testing leads to new understanding of bears
A century and a half ago, Norway was home to roughly three thousand brown bears, the majority of bears in all of Scandinavia. By 1930, the bears were virtually extinct. Decades of aggressive management tactics and bounties had wiped out one of the area’s most iconic species.
Brown bears have made a miraculous comeback in the time since.
“There is some research now that shows that probably there have been a few refugee areas, like mountainous and forested areas, where they maybe retreated to and have now expanded from,” said Alexander Kopatz, a researcher at Bioforsk Svanhovd, one of the leading brown bear research centers in Europe.
One of these refugee areas may have been in the Pasvik Valley, where the Svanhovd DNA lab is located. Svanhovd has been collecting detailing genetic information for just over 10 years; the data and research have not only lead to better local bear management, but a more thorough understanding of population recoveries and bear biology as well.
“I was actually very happy to see the genetic patterns in recovery, because normally wildlife conservation genetics is all about endangered species. This is a success story,” Kopatz said. “It gives you some hope that things are not that bad as they can be.”
Norway now has two distinct genetic populations of brown bears, one in the Pasvik Valley and the other along the Swedish border. Both were exterminated in the same manner, and yet, the population recoveries have happened in dramatically different processes.
According to Kopatz’s research, the Northern bears were bolstered by Russian bears migrating west, into Finland and Norway. Southern bears have a completely different genetic profile, sharing DNA with Swedish bears.
“The Russian bears helped the Finish bears, and probably the bears here too, to recover, and probably in a very rapid manner. Within a few decades,” he said. “You would not expect that based on older studies and theoretical studies.”
Both Norwegian bear populations are on the edge of larger regional populations, according to Miljødirektoratet wildlife advisor Veronica Sahlén said. This not only makes Norwegian management heavily dependent on what happens on the other side of its borders, but also means that the populations in Norway recover quite differently, and rely on the migration of mature female bears.
“We’ve always known we have a shared population, but these results kind of emphasize and confirm our suspicions as managers,” she said. “It’s natural, because we have such a long border, that we start collaborating with Sweden, but we’re of course hoping that in due time we can also collaborate with the Finnish and Russian management as well to find common monitoring systems.”
Sweden had about 2,550 bears in 2005, but because of efforts to reduce the population, is losing more and more bears every year.
“We do have a female population on the Norwegian side, so if they can continue to grow and reproduce and have that possibility, then they can sort of be delinked from what goes on on the Swedish side,” Sahlén said. “But we are largely dependent on our neighboring countries’ management strategies.”
According to Svanhovd director Snorre B. Hagen, the DNA research at Svanhovd only reinforces the need for cross-border cooperation and joint management plans.
“The bears don’t care about borders,” he said.
Bordering countries’ bear populations significantly affect Norway’s bears, which is one of the reasons why Norway is below its target population numbers in each of its management zones. While the national target is 13 litters born every year, it was estimated that just six litters were born in 2014.
Nevertheless, DNA analysis shows that there are at least 136 bears in Norway, and according to Kopatz, these populations are quite stable.
The same cannot be said for Russia’s bears. In fact, almost nothing can be said about Russia’s bears.
“Russia is a big black box. Nobody really knows how many bears are there,” Kopatz said, but added that he and his team are working with partners in the Kola Peninsula and other parts of Russia to analyze DNA samples.
Bioforsk Svanhovd uses both fecal and hair samples to study DNA. It relies on a few genetic markers to be able to tell an individual bear’s gender and if it is a breeding individual. Currently, the research team is looking at the Y chromosome of bears’ DNA to see how male bears migrate and influence the genetics of local populations.
“It is easier when you have these facts available to have a discussion about how we solve some of our mutual challenges,” Sahlén said.
Before the DNA research, evidence of Norway’s bear recovery was largely anecdotal, and wildlife advisors had to rely on bear observations, which is highly subjective to error. With this new database, management organizations have a far more accurate tool to judge how and in what way to handle Norway’s brown bears.
Kopatz says that the local management is very interested in bears’ pedigrees, but that the amount of data to detail family trees just is not there yet. He himself hopes that one day, the data will be used to identify illegal hunting.
“One of our goal as researchers and people that study bears is to increase the knowledge about bears, not just overall, but also locally,” Kopatz said. “It is very clear that the more people in the area know about bears, the more they are likely to tolerate them or like them and to support these issues.”
