they might want to knock out the competition, exclude Arctic foxes from the denning area," said Roth, a professor in biological sciences at the U of M. "But we actually haven't found that occurring." "We're finding more red foxes out on the tundra and in Arctic fox dens, and there is speculation that. Using fur harvest records between 19, the team inferred that Arctic foxes have been on the decline, while red foxes have moved further north into Arctic fox territory. Roth said it's tough to know exactly how many Arctic foxes once roamed northern Manitoba, but he suggested it's safe to say the population is at least half the size it was in the 1950s. That, combined with the latest research, suggests the dens are "ecological hot spots that have positive benefits for plants and animals alike," he said.īut it's another study by Johnson-Bice this year, co-authored by his PhD supervisor Jim Roth, that puts into context how losing Arctic foxes could impact other plants and animals in enmeshed in Arctic food webs. Johnson-Bice and others published a separate paper last year that demonstrated caribou, polar bear and wolves all visited Arctic fox dens more often than other similar areas on the tundra. Through analyzing high-resolution satellite imagery, the team found they could pick out dens from above.Īrctic fox cubs stand near a den site. It's at these edges where the seasonally snow-white polar predators occasionally decide to dig out dens in otherwise nutrient poor ridges on tundra without much vegetation. Satellite imageryĬhurchill, about 1,000 kilometres north of Winnipeg, and the neighbouring Wapusk region to the southeast represent the southernmost range of Arctic fox habitat. In one study, Johnson-Bice and his colleagues spied on Arctic fox dens - from space. "These dens are also really important sites likely for other species as well." "We have classified Arctic foxes as the sort of unique keystone ecosystem engineers in tundra ecosystems because they benefit other plants in the area through their denning activity," said Sean Johnson-Bice, a PhD candidate at the University of Manitoba. That's according to two separate studies published this summer based on recent research in the Churchill area. The effects of climate change appear to be driving Arctic fox numbers down in northern Manitoba, threatening their role as "ecosystem engineers" that have a green thumb effect on relatively barren swaths of tundra.
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