Modelling the spatial population dynamics of arctic foxes: the effects of red foxes and microtine cycles

Authored by Mark D F Shirley, Bodil Elmhagen, Peter W W Lurz, Steve P Rushton, Anders Angerbjorn

Date Published: 2009

DOI: 10.1139/z09-104

Sponsors: No sponsors listed

Platforms: C

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

wThe Fennoscandian arctic fox (Vulpes lagopus (L., 1758)) population is critically endangered, possibly because of increased interference competition from red foxes (Vulpes vulpes (L., 1758)) and fading cycles in microtine rodents, which cause food shortage. It is not known how these factors drive arctic fox population trends. To test their role in arctic fox decline, we developed a spatially explicit and individual-based model that allowed us to simulate fox interactions and food availability in a real landscape. A sensitivity analysis revealed that simulated arctic fox population size and den occupancy were strongly correlated with fecundity and mortality during the microtine crash phase, but also with red fox status. Model simulations suggested that arctic fox population trends depended on microtine cycles and that arctic fox distributions were restricted by red fox presence. We compared the model predictions with field data collected at Vindelfjallen, Sweden. The model recreated the observed arctic fox trend only with the inclusion of arctic fox avoidance of red fox home ranges. The results indicate that avoidance behaviours can affect population trends and hence that relatively small numbers of red foxes can have a strong negative impact on arctic fox population size and distribution.

Tags

Management Simulation-model Interspecific competition Wolves Social-organization Alopex-lagopus Vulpes-vulpes Grey squirrel Coyotes Fennoscandia