The Herpetological Journal

pp.263-271

Authors: Adrian Hailey

Abstract: Part 1: Line transect methods were used in three areas with known densities of Testudo hermanni. This enabled calculation of the proportion of the population available for finding ( PAF); that is, excluding tortoises in refuges or in thick cover. At times of peak daily activity PAF varied between about 0. 1 and 0.3, and was greater in spring than in summer. Males had higher PAF than females on summer evenings, the main courtship period, and PAF of males was greater in a population with a male-biased sex ratio. Transect sampling is useful for estimating the density of tortoise populations, provided that the low PA F is taken into account. Values of effective transect width are given for a variety of habitat types.
Part 2: A small population of T. graeca at Alyki was studied between 1980-1986; its size was estimated at about 25 adults, with an even sex ratio. Immature animals were recruited into the adult population, which was stable or increasing during this period. Adult size and juvenile growth rate were similar to other coastal populations of T. graeca in the region. The implications for the conservation of endangered tortoises are discussed.