Ecology and Reproductive Cycles of the Introduced Gecko, Hemidactylus turcicus, in the Southern United States

Abstract

The Mediterranean gecko, Hemidactylus turcicus, is firmly established in the southern United States. Animals were active immediately after nightfall and there was a decrease in numbers of active individuals after midnight. Eighty-two percent of the geckos recaptured one time were within 6 m of the initial capture site. There was no correlation between distance moved by a gecko and time of recapture after marking. Juveniles regenerated their tails faster than males and males faster than females. The relative tail length (tail length/snout-vent length) increased ontogenetically. The sex ratio of adults was almost exactly 1: 1. The reproductive season extended from April to August and females matured in the winter or spring of their second year. About two months were required to produce one clutch of two eggs; each female produced from two to three clutches per season. Eggs were laid in a cleared space and covered with debris. The average incubation period was 40 (37-45) days. Hatchlings had an average snout-vent length of 25.9 (25.0-27.7) mm and resisted starvation and dehydration for 30 to 33 days. In August, the testes were regressed but in December numerous primary spermatocytes were present and spermiogenesis was in progress. In January, one specimen contained a few sperm in the epididymides and the lumina within the testes were well developed. In July, spermatogenic activity was reduced but sperm remained packed in the epididymides. Light period may be the predominant environmental factor controlling reproduction in Hemidactylus turcicus in southern Louisiana.