Reproductive parameters in female European wildcats (Felis silvestris) across environmental gradients

Our understanding of the ecological factors and species-environment interactions driving reproduction in wildlife populations is limited. Collecting reproductive data across environmental gradients at the distribution range is particularly challenging in mammalian carnivores, though necessary to understand how environment and reproductive parameters interact. We explore the effects of environmental conditions on the reproduction of the European wildcat ( Felis silvestris ). By combining multiple survey methods we gathered a unique large-scale dataset of reproductive data across Europe. We assessed litter size, birth timing, birth synchrony, and reproductive rates of wildcats and determined the influence of anthropogenic, climatic and habitat factors on these reproductive parameters. Wildcat litter size ranged between one and six kittens with an average of 2.09 (± 1.30 SD). Litter size estimates varied substantially across survey methods. No significant effects of environmental or anthropogenic variables on litter size were detected. Female wildcats exhibited a long reproductive season, with births occurring between March and October with two distinct peaks in late April and August. Females at high elevation gave birth later and with higher synchrony but the effects of elevation and latitude could not be disentangled. Female reproductive rate -proportion of females reproducing- estimated from 14 females in a forested area of the Central European population was 0.79. Our study provides key reproductive parameters of wildcats. Our results are essential to plan and inform species-specific conservation actions and to improve our understanding of wildcat population dynamics. This study highlights the importance of international research networks to advance species research and conservation.