Inter- and intra-site differences in wild goat (Capra aegagrus) habitat quality detected through male horn size comparisons in Greek islands

Abstract

In caprid taxa, horn size is correlated with body mass, being a potential indicator of habitat quality. In this study, horn length and circumference measurements of, genetically similar, native island (Samaria National Forest Park, Crete) and introduced islet (a Game Breeding Station, and a Controlled Hunting Zone) populations of the Vulnerable agrimi were compared and evaluated with respect to population size information. Horns belonged to male animals that died between 1975 and 2016. There were significant age-related differences in inner horn length (annual increments and total) and annulus circumference between the three areas reflecting differences in food resources. Longest horns currently grow in the Controlled Hunting Zone. Length appeared negatively associated with population density. Results, also, showed that, in the short term, forage improvement can reverse horn size decrease trends. To support conservation efforts, it is suggested that native range and islet managers should establish horn measuring in monitoring practices.