Prey spectrum, prey preference and consumption rates of Eurasian lynx in the Swiss Jura Mountains

We examined 617 kills made by radio-tracked Eurasian lynx Lynx lynx (Linnaeus, 1758) from March 1988 to May 1998 to assess prey spectrum, preference, and food consumption rates in the Swiss Jura Mountains. Roe deer Capreolus capreolus and chamois Rupicapra rupicapra were the main prey (69 and 22%, respectively), followed by red fox Vulpes vulpes, brown hare Lepus europaeus, domestic cat Felis catus, wild cat Felis sylvestris, marmot Marmota marmota, pine marten Martes martes, capercaillie Tetrao urogallus, and badger Meles meles. Lynx fed on an ungulate prey from 1 to 7 days, depending on the prey category. The consumption rates of males, of females alone, and of females with kittens varied from 3.2 to 4.9 kg per night, with an increasing trend as the kittens grew older. Including the days when lynx had no kill (searching time) lynx consumed 2 +/- 0.9 kg per night. The mean searching time was 1.5-2 days for females, depending on the season and the number of kittens, and 2.5 days for males. The mean interval between consecutive kills was 5.9 for males and 5.2 days for females, respectively. At 38% of carcasses the presence of one or several scavengers (red fox, raven Corvus corax or both) was detected. Although 69% of the kills were roe deer and only 22% chamois, we hypothesise that in the forests of the Jura Mountains chamois are more vulnerable to lynx predation than roe deer, as chamois had a slightly higher preference index (0.59) than roe deer (0.41), based on rough estimates of the two ungulate populations in the study area.