Protected areas shape the spatial distribution of a European lynx population more than 20 years after reintroduction

The Bohemian Forest harbours one of the largest lynx populations in Central Europe, which arose from animals reintroduced in two adjacent national parks. Despite an increasing number of population modelling approaches, the differences between potential and realised lynx distributions urgently need to be explored. We used lynx monitoring data from 2005 to 2010 from 530 municipalities in eastern Bavaria and spatial estimates of roe deer densities to test the predictions that the probability of lynx occurrence (confirmed or unconfirmed) increases with (1) decreasing distance to the national park area, (2) increasing forest cover, (3) increasing proportion of state-owned forests, (4) increasing roe deer density and (5) decreasing human activity. Using a flexible additive boosting model, we identified the distance to the national parks as the dominant factor, with positive effects on lynx probability only up to 70 km from the centre of the two national parks. Moreover, forest cover and roe deer density were correlated with increasing lynx occurrence. The probability of unconfirmed lynx occurrence increased with the proportion of state-owned forest within a municipality. The most probable mechanism behind the distance variable is illegal killing outside of the national parks. We concluded that despite the small size of protected areas in Central Europe, they still provide important source areas for this large predator. Moreover, the results supported conclusions of previous modelling approaches on the exchange among existing subpopulations in Central Europe, and indicated that lynx currently might not be able to colonise the next suitable areas.