The Reproductive Cycle of the Viviparous Mexican Lizard Sceloporus torquatus

Abstract

The reproductive cycle of the lizard Sceloporus torquatus was determined using data obtained from field caught and museum specimens. Males exhibit testicular recrudescence during late summer and maximal testicular volumes occur during September and October. Similarly, females begin vitellogenesis in late summer, culminating in ovulation during November or December. Females are pregnant throughout the winter months with birth in April or early May. Average clutch size is 9.7 young. Neonates of both sexes are born early in summer, achieve adult size within five months and are thus capable of reproductive activity the first fall after birth. This study adds to the data that indicate that fall reproductive activity is the common reproductive strategy among viviparous lizards of the genus Sceloporus