ECOLOGY OF THE WHIPTAIL LIZARD CNEMIDOPHORUS-DEPPII ON A TROPICAL BEACH

The whiptail lizard Cnemidophorus deppii was studied during late dry s eason on a tropical beach on the Pacific coast of Nicaragua. Most aspe cts of the ecology of this species are similar to those of other activ e foraging lizard species studied. Individual C. deppii spend most of a typical daily activity period on sand moving from vegetation patch t o vegetation patch, presumably in search of food. The amount of time s pent in the sun is greatest in early morning and at its lowest level a t midday. The average rate of movement was 0.048 +/- 0.004 m/s. Body t emperatures of active lizards averaged 40.0 +/- 0.25 degrees C, and mo st activity occurred during morning and late afternoon. Body temperatu res were significantly lower in whiptails active during the morning th an later in the day. Forty-two types of prey were identified in stomac hs, with termites, spiders, and various orthopterans accounting for mo st of the diet volumetrically. There was no correlation between lizard size and prey size. There was a significant negative relationship bet ween prey width and the number of prey in stomachs. Snout-vent length (SVL) at sexual maturity was 60 mm for females and 58 mm for males. Ma ture females averaged 63.8 +/- 0.7 mm SVL and produced clutches varyin g from 1 to 3 eggs ((x) over bar = 1.8 +/- 0.2). Oviductal eggs averag ed 13.6 +/- 0.64 x 7.7 +/- 0.21 mm in size. There was no significant r elationship between female SVL and clutch size. Relative clutch mass w as similar to that for other active;foraging lizard species. Sexual di morphism was apparent in coloration (males brightly colored), body siz e (males larger), and relative head size (male heads larger independen t of body size differences). These differences presumably are due to s exual selection.