An unusual predator-prey system including Iberian lynx and roe deer

The Iberian lynx (Lynx pardinus) is a recently recovering felid native to the Iberian Peninsula. This specialist relies on European wild rabbits (Oryctolagus cuniculus) as its bulk prey. Occasionally however, Iberian lynxes can prey on ungulates. New situations emerge in the context of ongoing Iberian lynx recovery and roe deer (Capreolus capreolus) expansion. The capacity of Iberian lynx to influence roe deer dynamics is unknown. We addressed this gap combining camera trapping, noninvasive genetics, and pathology on a site where a saturated Iberian lynx population coincides with a significant roe deer population. Lynx and roe deer detections were not spatially correlated. By contrast, lynx detections were correlated with rabbit detections. We estimated lynx density and roe deer density at 0.167±0.042 lynx/km2 (SCR models) and 3.55±2.26 roe deer/km2 (REM method), respectively.  Roe deer fawn recruitment was low as the proportion of fawns per adult female was 23%. We detected roe deer DNA in two of 15 lynx feces. One freshly dead adult female roe deer was found by gamekeepers. Two CTs immediately set up at the presumed kill site and kept activated for eight hours recorded three visits by a collared adult female Iberian lynx. The carcass presented lesions compatible with lynx predation. Thus, we compiled CT-derived, genetic, and pathological evidence confirming that Iberian lynxes prey on roe deer. Iberian lynx predation on roe deer is probably sporadic. However, predation has a significant effect on roe deer dynamics in the study site, impeding normal fawn recruitment and the establishment of a harvestable population. Our findings have implications for hunter attitudes, game management and lynx conservation.