Seasonality and reproduction in wild-living cats in Scotland

The definition of the wildcat Felis silvestris Schreber, 1775 in Scotland is contentious, in light of long-term interbreeding with domestic cats F. catus Linnaeus, 1758. Two morphological groupings (Group 1 and Group 2) have previously been proposed to explain the variation found in wild-living cats in Scotland, with Group 1 cats closest to wildcats and Group 2 cats to domestic cats. Data from the reproductive tracts of 185 wild-living cat carcasses and evidence of reproductive activity in 31 live cats were analysed in order to compare reproductive activity between the morphological groups, and in relation to seasonality and existing data on wildcats and domestic cats. For males, Group 2 cats had a greater mean relative testes size than Group 1 cats. Estimated from corpora lutea, there was a suggestion that Group 1 females showed more seasonality in oestrous than Group 2 cats. In all wild-living cats, the mean litter size was 4.3 and estimated birth dates were throughout the year, but least in winter. A high number of pseudopregnancies were recorded. The results were consistent with the hypothesis that Group 2 cats are closer to domestic cats. However, the variation observed in the sample of wild-living cats reported here, suggested that reproduction was neither strictly seasonal nor outside the range observed in some feral cat populations.