Saving the Arctic fox in Fennoscandia

Background

The Arctic fox is one of the mammals which have been present the longest period on the Scandinavian peninsula. They followed the edge of the glaciers when they retreated after the Ice Age, about 10 000 years ago. Until 19th century the Arctic foxes were abundant above the tree line in the mountain, but due to large hunting pressure the population decreased rapidly. Despite being protected in Sweden since 1928, the arctic fox has not made it back in numbers as before. Similar stories can be told from both Norway and Finland.

Today, the number of adult foxes in Sweden is only about 60 individuals, which is also the total number of Arctic foxes within EU, while no breeding has been noted this year (sofar) in Finland. Normally, the prey abundance varies with a 4-5 years cycle following the rodent (mostly scandinavian lemming)  peak and bottom years. In years with very few rodents, the arctic foxes do not breed, while years with high abundance they can have litters with more than ten pups (record being 18 pups). The reproduction success during these peak years (and the year building up to it) are very important to the population size.

The main threats today are a) prey abundance (in summer lack of lemmings/rodents and in winter carcases of reindeer), and b) an increase of red fox within the habitat of the smaller arctic fox. The red fox is taking over den sites and can kill arctic foxes. The most important measures to help the Scandinavian arctic fox population is to provide supplementary food at den sites and to reduce red foxes close to the arctic fox dens.

Project progress

During 2009, only two litters (in total 4 pups) were observed in Sweden , and the situation for 2010 was very bleak. However, in 2010 the lemming population suddenly started to increase and to most peoples surprises 25 arctic fox litters have been observed. Most of them are in the mountains in Counties of Jämtland, Västerbotten and Västernorrland, where the money from EAZA European Carnivore Campaign is being used. Without the help from the personnel from the County boards, the reproduction for the arctic foxes would most likely have been much less. The EAZA-money has made it possible to pay for supplementary feeding both during the hard long winter and during this summer. On top of that many red foxes have been removed close to arctic fox dens. Scientists at Stockholm University have also had part of their field work paid by EAZA. The research team (led by Prof Anders Angerbjörn) have many ongoing long-term studies e.g. genetics, movements of tagged individuals, behavioural studies etc. The results from the studies are used to help the management of the Scandinavian population of the arctic foxes. The weight of the arctic fox pups this year is above normal which is a good sign, and hopefully many pups will survive this coming winter.

The year 2010 do not seem to be the peak year for lemmings, they are still increasing in numbers, and hopefully the peak might happen next summer, if the lemming population does not crash next spring. If the lemming population continues to grow, the summer 2011 will be a fantastic arctic fox year. The supplementary feeding will continue this coming winter, to help as many as possible of the foxes to survive to summer 2011. Just now it looks bright for the arctic foxes!