Relatively high but narrow incubation temperatures in lizards depositing eggs in warm and thermally stable nests

摘要

We used the Reevese’s Butterfly Lizard Leiolepis reevesii as a model animal to test the hypothesis that incubation temperatures should be relatively high but narrow in lizards depositing eggs in warm and thermally stable nests . Eggs were incubated under three constant (27, 30 and 33 ° C) and one fluctuating temperature regimes. Hatchability was highest at 30 ° C and lowest at 27 ° C. The mean rather than the variance of temperatures affected incubation length, and the mean incubation length was 101.1 days at 27 ° C, 69.6 days at 30 ° C and 55.3 days at 33 ° C . Incubation temperature did not affect the sexual phenotype of hatchlings . H atchlings from different treatments showed little variation in morphological phenotypes, but differed significantly in locomotor phenotypes. Hatchlings incubated at 27 ° C performed much more poorly in the racetrack than did hatchlings from the other three treatments, and the variance of incubation temperatures negatively affected sprint speed of hatchlings. The incubation temperatures of 27 ° C and 33 ° C supported egg incubation, but these two temperatures were not ideal. T he range of temperatures suitable for incubation of L. reevesii eggs presumably lies between the range of nest temperatures varying most frequently from 28 ° C to 32 ° C. Compared with results reported for other squamate reptiles either from cool habitats or from warm habitats but depositing eggs in shallow nests, temperatures suitable for egg incubation are relatively high but narrow in L. reevesii . Thus, our data validate the above hypothesis [ Acta Zoologica Sinica 53(3): 437 –445, 2007].