FoxSim An individual-based population model of foxes and sarcoptic mange Gösta Nachman and Mads C. Forchhammer Department of Population Ecology Zoological Institute University of Copenhagen

Mads C. Forchhammer and Tommy Asferg: ”Invading parasites cause a structural shift in red fox dynamics” Proceedings of the Royal Society B (2000), 267,

Sarcoptic mange is a skin disease It is caused by the mite Sarcoptic scabiei var. vulpes Latency period from exposure is approximately one month The mite causes severe skin lessions and loss of hair Infected foxes usually die from starvation Infected animals normally live 7-8 months as compared with 3-4 years of heathy individuals Recovery from mange is rare

Photo Credit To: Clyde Isaak, Jamestown, N.D.

Fox territoryMale fox Female fox Offspring Offspring leave parent’s territory in order to establish their own Single foxes tend to leave a territory Mortality during dispersal depends on distance Fight to gain territory

Infected maleHealthy female Infected offspring Infected pairs produce less offspring Sick individuals infect healthy ones by physical contacts Healthy individuals have higher mating chance Infected individuals have reduced fitnessSick individuals never recover from the disease