Population monitoring of Arctic fox

The Norwegian Polar Institute is responsible for monitoring of the arctic fox population on Svalbard. The arctic fox is monitored because 1) they are top predators that have significant impacts on both the terrestrial and marine ecosystems, 2) they are hunted annually and 3) they are important vectors for rabies and Echinococcus multilocularis.

Den surveys are carried out annually in two areas, one in Kongsfjorden - Brøggerhalvøya and the other in Adventdalen-Sassendalen. The survey in Kongsfjorden - Brøggerhalvøya commenced in 1990 and is ongoing. It covers an area of 221 km². The den survey in Adventdalen-Sassendalen started in 1982 and ended in 1989, but started up again in 1997 and is now conducted annually; it covers an area of 900 km2.

Records to date for the arctic fox den survey is posted on NPI’s MOSJ web-site. Data from harvesting is also collected as part of the monitoring programme. Since 1996, NPI has collected and stored frozen carcasses of arctic foxes that have been trapped during winter (80 - 160 foxes are trapped each year). NPI started the autopsies of these animals in 2002. Records to date for annual trapping of the arctic fox is posted on NPI’s MOSJ web-site. Data on age structure, sex ratios, pup production, diet, body condition, location of harvest and year of harvest are collected to estimate mortality rates, population structure and population dynamics are collected. In addition, research on persistent organic pollutants (POPs) in relation to feeding ecology (stable isotopes) has been carried out on samples from 1998-99. Records to date for POPs in the arctic fox is posted on NPI’s MOSJ web-site.

This work is conducted in cooperation with Örebro University and Norwegian Institute for Nature Research, Tromsø. Genetics studies are also ongoing, looking at potential fine-scale genetic structuring in the arctic fox population on Svalbard. Samples are also included in a circumpolar genetic study. This work involved a wide international cooperation, which includes among others the University of Alberta, Tel Aviv University and Stockholm University.

Infectious diseases and parasites are also subjects of study in the monitoring programme. The arctic fox is known to be the major vector of rabies virus in the Arctic region. The arctic fox is also the determinant host of the tape worm Echinococcus multilocularis which has become established in the Grumant area in Isfjorden. This work is conducted in cooperation with the National Veterinary Institute, Tromsø, the Norwegian School of Veterinary Science, the Department of Arctic Veterinary Medicine Tromsø, University of Tromsø, the National Veterinary and Food Research Institute in Oulo, Finland and Forest Research Institute, Finland. Some components of this NPI programme are assisted by the Governor of Svalbard.

Prosjektleder: Dr. Eva Fuglei