Show me your tail, if you have one! Is inbreeding depression occurring in wildcats (Felis silvestris silvestris) from Italy?

Abstract

Knowledge of genetic diversity is important to wildlife conservation because genetically depleted populations experience an increased risk of extinction. Mammalian carnivores are characterized by small and fragmented populations and low dispersal, so that genetic erosion can lead to the fixation of deleterious genes relatively quickly, leading to morphological abnormalities. Kinked tails and cowlicks are indicative of inbreeding depression and have been described in two wild cat species so far, the puma (Puma concolor) and the cheetah (Acinonyx jubatus). Here we report the first records of morphological abnormalities in five populations of the European wildcat (Felis silvestris silvestris) in Italy by using (1) camera-trapping and (2) necropsy of road-killed individuals assessed through genetic analysis. We collected 24,055 trap-nights from 251 cameras and recorded 566 wildcat detections, from which we identified 148 wildcats. Among these, 11 individuals had a kinked tail and four displayed brachyuria, whereas three wildcats from Sicily had cowlicks on the thorax. We recovered 28 road-killed wildcats and two of them (from Sicily and Friuli Venezia Giulia) had a kinked tail. Among these, one female with a kinked tail had a male foetus with a kinked tail, which proved that this characteristic was genetically inherited. We are unsure why brachyuria or cowlicks were not detected across all monitored wildcat populations, given we found kinked tails throughout Italy. The frequencies at which we have detected these abnormalities in wildcats are far lower than reports from Florida panthers (Puma concolor). Future research is needed to verify whether these abnormalities are also associated with low genetic diversity or other morphological defects which might lower fitness. We recommend a nationwide effort, using these techniques within a standardized sampling design, to further understand the status of the wildcat in Italy.