The original population of wolves living in Norway and Sweden were wiped out 50 years ago, a report commissioned by the Norwegian parliament has concluded.
Roughly 12,000 years ago, as the northern hemisphere’s gigantic ice sheets were in full retreat, wolves (Canis lupus lupus) arrived in what is now Norway and Sweden. Over time, these wolves formed a distinct population, acquiring a heavier build and deeper shoulders in contrast to their Eurasian counterparts. By 1970, however, wild Swedish-Norwegian wolves had disappeared, primarily the result of human hunting and ongoing conflicts with farmers.
Or so it seemed. Rumors began to swirl in the 1980s that captive Swedish-Norwegian wolves were being reintroduced to the wild and that the species was making a comeback. This seemed to make sense given that hundreds of wolves were found living along the Swedish-Norwegian border. With their status uncertain, Norway’s parliament commissioned a report in 2016 to determine what was actually going on. In an email to Earther, Hans Stenøie, director of Norwegian University of Science and Technology’s University Museum and the first author of the report, said questions were raised regarding the veracity of prior research. The Norwegian parliament “wanted a new evaluation of the genetic and geographic origin of the Norwegian wolves, using state-of-the-art methodology,” he explained.
Preliminary findings were filed in 2017, but the final report has now been released. Led by NTNU researchers, the final report concludes that the current population of wolves now living in this area are not native to the region, having arrived from Finland. Nature abhors a vacuum, as the old saying goes, so with the native wolf population gone, the Finnish wolves were able to expand their territory and move right in.
“We’ve carried out the largest genetic study of wolves in the world,” Stenøien told Norwegian SciTech News, which reports research news from NTNU. The team collected DNA from 1,800 wolves from around the world, particularly those from Europe, of which 72% were deemed usable for the study. Whole genome comparisons were performed for added thoroughness. Results showed that the current population of wolves living in Norway and Sweden are distinct, having never interbred with the now-extinct native population. The report shows the original Swedish-Norwegian wolf is truly gone, save for a few individuals currently living in zoos.
But all is not well with the Finnish ex-pats. The current population of roughly 400 individuals was found to be genetically distinct from their Finnish ancestors, but the report says this isn’t the result of new adaptations—it’s the result of inbreeding. The size of this wolf population is too small, leading to a lack of genetic diversity. That these wolves are inbred could also mean that the original population of replacement wolves was small to begin with, according to the report. Because inbreeding makes animals more susceptible to diseases and genetic conditions, the replacement wolves could likewise follow their Norwegian-Swedish counterparts into extinction.
Interestingly, the replacement population showed very little signs of having interbred with domesticated dogs.
“The Norwegian Storting [parliament] not only wanted to know the genetic origin of the Norwegian-Swedish wolves, but also the extent of hybridization with dogs,” Stenøie told Earther. “We show that they are genetically most similar to Finnish wolves, and that there are few if any other wolves in the world with less dog in their genomes,” he said, adding that “Norwegian-Swedish wolves are ‘pure’ in this respect.”
The new report presented these facts without any commentary about future wolf management. That will now be up to politicians and special interest groups. The reintroduction of wolves is a very divisive issue in Norway, as it is in North America. Rewilding efforts are currently underway in the U.S, including in Yellowstone National Park and in Colorado, and they’re likewise contentious. Supporters of rewilding say it’s important to re-balance the food web, while critics, mainly farmers and hunters, worry about their livelihoods and pastimes.