Predation on livestock by an expanding reintroduced lynx population: long-term trend and spatial variability.
Abstract
In recent decades, the Eurasian lynx Lynx lynx has recolonized former habitat, bringing it into potential conflict with livestock. We studied the spatial and temporal distribution of lynx attacks on sheep in the French Jura, northeast France, between 1984 and 1998, during and after its population expansion. We estimated the local and regional impact of lynx predation on livestock. The number of attacks increased from three in 1984 to 188 in 1989, concurrently with the colonization of the main sheep range by lynx. During subsequent years, 66-131 attacks were recorded annually (92-194 sheep killed per year). On the average, 1.6 sheep were killed per attack. Lynx preyed disproportionately on lambs and subadult sheep. A small percentage of flocks (9.5-22.9%) were attacked, most of which (75.2%) were attacked once or twice a year. At the regional level, annual sheep losses to lynx were 0.14-0.59% of the total number of sheep. The major lynx-livestock problem was due to clustered attacks in a few small areas. Each year, two to six 'hot spots' (33-69% of the attacks) were identified. Hot spots covered 0.3-4.5% of the total area where attacks occurred (1835-4061 km2). Roe deer (Capreolus capreolus) abundance was higher in hot spots and, even here, sheep only made up 3.1% of the lynx diet. These data show that lynx were not killing sheep due to shortages of alternative prey or in response to an increased need for food when rearing young. The concentration of hot spots in only nine small areas between 1984 and 1998 indicated that only a few individual lynx were involved. The reappearance of hot spots at the same sites, after years of interruption and despite the removal of lynx, suggested that the ultimate factors causing hot spots were factors inherent to those sites. Further investigation is needed to identify causal factors with a view to eliminating them. These may relate to landscapes features, animal husbandry practices or the behavioural ecology of lynx. In future, where large predator reintroductions are planned, the potential for concentrated, localized, impact should be evaluated and mitigation measures put in place. For scattered and episodic lynx damage, financial compensation is the only realistic option at present. In hot spots, the cost-effectiveness of guard-dogs or the selective removal of some individual lynx should be evaluated.