HATCHING SUCCESS, DELAY OF EMERGENCE AND HATCHLING BIOMETRY OF THE SPUR-THIGHED TORTOISE, TESTUDO-GRAECA, IN SOUTH-WESTERN SPAIN

Hatching success, egg incubation, emergence and hatchling characterist ics were assessed for 44 naturally incubating nests of Testudo graeca in south-western Spain. Nest predation rate was 4.5% and overall hatch ing success was 82.4%. Incubation periods ranged from 78 to 114 days, and hatchlings delayed emergence from the nest from one to 23 days. Em ergences occurred from mid August to late September, and were not corr elated with nesting dates, but earlier laid nests had longer incubatio n times, which was probably owing to lower temperatures experienced by clutches laid at the beginning of the nesting season. Variance of hat chling body size and mass was high and was mainly influenced by the gr avid female. Mean straight carapace length was 34.14 mm, and mean body mass 10.8 g. Hatchlings from clutches laid last in the nesting season had significantly better physical condition. Hatchling mass was posit ively correlated with egg mass, and both Variables were positively cor related with emergence date. Both better physical condition and relati vely late emergence may confer advantages to hatchlings in the face of unfavourable environmental conditions in autumn.