CLUTCH FREQUENCY, EGG AND CLUTCH CHARACTERISTICS, AND NESTING ACTIVITY OF SPUR-THIGHED TORTOISES, TESTUDO-GRAECA, IN SOUTHWESTERN SPAIN

Reproduction in female spur-thighed tortoises (Testudo graeca) in a po pulation from southwestern Spain was studied by X-radiography of threa d-trailed and radio-tagged individuals. Most females reproduce every y ear, laying one to four clutches from April to June with internesting intervals ranging from 21 to 29 days. Clutch size varied from 1 to 7 e ggs and averaged 3.5 eggs. Carapace length and mass of females were po sitively correlated with the starting date and duration of the nesting season, while age was not correlated with any reproductive variable. Eggs averaged 33.87 x 27.97 mm in dimensions and 14.4 g in mass. Femal e mobility increased shortly before or after nesting, which resulted i n wide dispersal of the various nests laid by an individual female.