Consistent specialization on roe deer across contrasting prey communities: diet and prey selection of Eurasian lynx in the Western Carpathians

The Carpathian population of the Eurasian lynx ( Lynx lynx carpathicus ) represents one of the most important native source populations for lynx conservation and reinforcement in Central Europe, yet ecological drivers of prey selection remain poorly understood. We investigated diet composition, and factors influencing prey selection in the Western Carpathians using an integrated approach combining GPS telemetry and systematic kill-site inspections, snow tracking, scat analysis, camera trapping and microsatellite genotyping for individual lynx identification from scats. Based on 446 prey remains and 386 scat samples collected across several mountain regions, we found that the lynx diet was overwhelmingly dominated by wild ungulates, which accounted for 96.0% of prey remains and 96.3% of total consumed biomass. Roe deer ( Capreolus capreolus ) was the main prey species, representing 64.6% of prey remains and 69.0% of consumed biomass, followed by red deer ( Cervus elaphus ; 27.6% and 24.8%, respectively). Despite substantial variation in ungulate community composition and the availability of alternative prey, roe deer remained consistently positively selected across all study areas. In contrast, red deer consumption increased with its relative availability and was more frequent in males, particularly during winter, indicating context-dependent flexibility in prey use. Non-ungulate prey contributed only marginally to the diet, and we found little evidence that lynx age, social status or population density substantially influenced prey selection. Our results demonstrate that Carpathian lynx remain strongly specialized on roe deer while retaining capacity to exploit alternative ungulate prey under specific ecological conditions. These findings improve our understanding of predator–prey interactions in a key European lynx population and provide an important scientific basis for conservation and management of lynx and its prey. Our integrated approach and findings also provide an ecological benchmark for anticipating predator–prey relationships as lynx recover across their former range through natural recolonization, reinforcement and reintroduction.