Effects of Caudal Autotomy on Postnatal Growth Rates of Hatchling Psammodromus algirus

Abstract

Tail autotomy has clear advantages regarding predator escape, but it also has several associated costs (i.e., impaired locomotion, loss of social status, and reduced growth and reproductive output). We examined the costs of severe autotomy on growth rates of hatchlings of the lacertid lizard sammodromus algirus during the first weeks of postnatal development. Hatchlings from two populations in central Spain were autotomized on the fifth day after hatching and kept in common garden conditions for 35 days when they were measured again. Hatchlings from both populations, independently of the autotomy treatment, did not differ in the mass gained during the experiment. However, there were differences in body growth between tailless and tailed hatchlings; tailless hatchlings grew at a slower rate than tailed ones, after controlling for the effects of body condition at the onset of the experiment and the resources assimilated. Moreover, independently of their population of origin, hatchlings that invested more in body growth also invested more in regenerating their tails, and no trade-offs were apparent. Because hatchlings were housed in common garden conditions, this result could be attributable to differences in individual capacity to obtain and assimilate resources.