Testudo hermanni boettgeri in the Balkans: geographic variability in morphology, and preliminary population viability analysis

Abstract

Members of the Serbian Herpetological Society, with colleagues from other Balkan countries and from France, conduct studies of various aspects of Testudo hermanni boettgeri biology. Capture-Mark-Recapture (CMR) studies were started in 2007. We processed approximately 3 200 Hermann’s tortoises inhabiting various environments in 7 localities, and being under different pressures. We thoroughly analysed geographic variability in body size and shape, as well as differences in the degree and direction of sexual dimorphism. We found that several body dimensions are invariable among our samples. Also, we noticed several peculiar states of bony shell, some of which we couldn’t find described in the available literature. We used the collected population data to run population viability simulations in the Vortex application. Given the marked differences in habitats under study, differences in population fate predictions were expected, but two populations appear extremely vulnerable: one isolated on the island and another one endangered with road-kills and fires. Since this species in Serbia (and entire ex-Yugoslavia) has never been under a long-term study previously, the data we collected are the first morphological and demographic information.