Reproductive characteristics of the island lacertid lizard Podarcis lilfordi

We report reproductive characteristics (clutch frequency, clutch size, egg and hatchling sizes) of the island lizard Podarcis lilfordi, studied in the laboratory. Individual females produced two or three consecutive clutches, composed of 2-4 eggs with an average mass of 0.63 g. Both clutch size and average egg mass were independent of female body length, and did not differ between the first and subsequent annual clutches. Among-clutch differences in egg mass were negatively correlated with clutch size, and this trade-of f is independent of female size. Larger clutches were also composed of less elongated (i.e., rounder) eggs than are smaller clutches, suggesting that limitations posed by the females' body volume, rather than by restrictions of energy availability, induce the phenotypic trade-off between egg size an d numbers. Egg shape was also related to female size: larger females laid s horter but wider eggs than smaller individuals, suggesting that egg width i s constrained by the width of the female's pelvic girdle. Relative to other European lacertids with similar adult female body length, P. lilfordi prod uces clutches that are composed of very few,but extremely large eggs.