Post-emergent field activity and growth rates of hatchling spur-thighed tortoises, Testudo graeca

Activity, mobility, growth rates, and space use of 48 hatchling spur-thighed tortoises, Testudo graeca, were monitored over st period of 8 months, from emergence from the nest in September until May. Individuals were followed by means of thread trailing and radio tracking. Overall average distance moved was 4.42 m/day and average home-range size was 13.7 m(2). Hatchlings were active from emergence until mid-December, exhibited discontinuous hibernation until mid-February, and reached highest activity and mobility values in April-May. Overall, mobility varied significantly with daily solar radiation values and maximum temperature, and was significantly dependent on body condition in winter. Body size and mass had no influence on individual performance, and a significant proportion of variance among individuals remained unexplained. Little growth occurred in autumn and body condition decreased steadily, increasing only from February onwards. Growth rates increased in March-April. No individual differences in growth rates were detected, initial body size being the main determinant of body size after 8 months.