Multi-seasonal systematic camera-trapping reveals fluctuating densities and high turnover rates of Carpathian lynx on the western edge of its native range

Abstract

Camera-trapping and capture-recapture models are the most widely used tools for estimating densities of wild felids that have unique coat patterns, such as Eurasian lynx. However, studies dealing with this species are predominantly on a short-term basis and our knowledge of temporal trends and population persistence is still scarce. By using systematic camera-trapping and spatial capture-recapture models, we estimated lynx densities and evaluated density fluctuations, apparent survival, transition rate and individual's turnover during five consecutive seasons at three different sites situated in the Czech-Slovak-Polish borderland at the periphery of the Western Carpathians. Our density estimates vary between 0.26 and 1.85 lynx/100 km2 suitable habitat and represent the lowest and the highest lynx densities reported from the Carpathians. We recorded 1.5-4.1-fold changes in asynchronous fluctuated densities among all study sites and seasons. Furthermore, we detected high individual's turnover (on average 46.3 +- 8.06% in all independent lynx and 37.6 +- 4.22% in adults) as well as low persistence of adults (only 3 out of 29 individuals detected in all seasons). The overall apparent survival rate was 0.63 +- 0.055 and overall transition rate between sites was 0.03 +- 0.019. Transition rate of males was significantly higher than in females, suggesting male-biased dispersal and female philopatry. Fluctuating densities and high turnover rates, in combination with documented lynx mortality, indicate that the population in our region faces several human-induced mortalities, such as poaching or lynx-vehicle collisions. These factors might restrict population growth and limit the dispersion of lynx to other subsequent areas, thus undermining the favourable conservation status of the Carpathian population. Moreover, our study demonstrates that long-term camera-trapping surveys are needed for evaluation of population trends and for reliable estimates of demographic parameters of wild territorial felids, and can be further used for establishing successful management and conservation measures.