Abstract
We suggest that the disappearance of the wolf from the Fennoscandian fauna has resulted in an increase of the red fox as a mesopredator in northerly areas with cascading effects on the arctic fox and mustelids. We will take advantage of the red fox removal programme within the EU/Life financed action programme to support the arctic fox population, SEFALO, to test what effects a removal of a mesopredator can have on an Arctic ecological community. Within SEFALO we remove red foxes in three experimental areas of about 600 km2 with control areas of similar size. We will monitor predator and prey populations during winter and summer using well documented methods in experimental and control areas. Our main question for predators is if there is an effect from a mesopredator on smaller predators: the arctic fox, least weasel and stoat. Specifically, we expect the density of small predators to increase when red foxes are removed due to intra guild predation. For prey populations our main prediction is that a red fox removal would result in an increase in density of ptarmigans, ducks, waders and passerines. There are both direct and indirect effects that could affect the dynamics of small rodents. A generalist predator, such as the red fox, can stabilise prey populations, but if specialist predators are essential in the small rodent population cycle, the reappearance of these could result in a higher small rodent dynamics with pronounced population cycles.
Sweden