Changes in red fox Vulpes vulpes diet due to colonisation by lynx Lynx lynx

Abstract We studied the diet of red fox Vulpes vulpes in the presence of lynx Lynx lynx in the southern boreal forest of Sweden during 1999-2002 using scat analyses. Diet composition and food niche breadth was compared to an identical study conducted in the same area during 1974-1979 prior to the recolonisation by lynx. The consumption of roe deer Capreolus capreolus was higher in the presence of lynx, even compared to the particularly harsh winter in 1976/77 when roe deer suffered serious starvation related mortality. Scavenging on roe deer replaced feeding on presumably less profitable food such as fish and reptiles, invertebrates and vegetables. The winter food niche was narrowed. The frequent consumption of roe deer could have been a combined effect of a stable supply of deer carrion and a low abundance of other prey species. We thus conclude that presence of lynx feeding on roe deer creates an important, stable food supply for red foxes.