Abstract

The adaptation of tail-autotomy is paradoxical in lizards which utilize the tail as a major fat-storage organ, because high rates of tail-loss are normal and because surrender of large fat reserves seems to amount to selective pressure favoring predation on such lizards. Experimental results demonstrate the existence of ta behavioral mechanism in Lygosoma laterale consisting of return by the lizard to where its tail was lost, a strong ingestion response to an inanimate automized tail, and movements by the autotomized tail which make its capture less likely. Laboratory evidence includes rates of ingestion of autotomized tails averaging nearly 40% for five species of skinks. This contrasts with rates averaging 3.4% for two iguanid lizards in which fat reserves are not stored in the tail. Tests with free-ranging L. laterale show that ingestion occurs in nature. Additional laboratory experiments quantitatively demonstrate escape behavior by tails of L. laterale. The results confirm a behavioral mechanism in L. laterale which compensates for the ready autotomy of major fat reserves. At the same time, two divergent evolutionary strategies of adaptation of the autotomic tail are defined.