Abstract

Field observations and lab studies were carried out on the Rough-tailed Gecko (Cyrtopodion scabrum) in the Suez Canal Zone to assess sexual size dimorphism, activity, habitat selection, growth rate, diet, and reproduction. Cyrtopodion scabrum showed no significant sexual difference in body size and head shape characters. The lizard's maximum activity was in autumn and the minimum in winter, with peaks of daily activity during the first 3 h following sunset; air temperature was a major factor controlling daily and seasonal activity of C. scabrum. Lizards were solitary and had small home ranges. They occupied all available substrates and assumed different positions at heights ranging from 5 to 500 cm above the ground. The greatest rate of growth occurred in spring, and growth ceased altogether during winter. Lizards with the smallest snout–vent length had the highest growth rate. A total of 14 arthropod orders were recorded in the diet of C. scabrum; dipterans and hymenopterans dominated in number and volume, respectively. Cyrtopodion scabrum showed evidence of a sit-and-wait foraging mode. Males and females both ate prey of similar numbers and sizes; however, lizard stomachs were filled with food in spring more than any other season, which may indicate the lizard's increased need for energy for reproduction. The reproductive season extended from March through September. Peak reproductive activity for both sexes was in June and July. Female C. scabrum deposited single-egg clutches more commonly than two-egg clutches and displayed communal nesting, which was previously unrecorded for the species.