Among Clutch Variation in Reproductive Output and Egg Size in the Wall Lizard (Podarcis muralis) from a Lowland Population of Northern Spain

Abstract

Among clutch variation in reproductive output and egg size of the wall lizard (Podarcis muralis) are reported. Females under semi-natural conditions laid eggs from late April to early July. The smallest reproductive female in our sample was 51.2 mm SVL, and all females larger than this size produced at least one clutch per season. Of the 53 females, 13 laid three clutches, 27 laid two clutches, and 13 laid one clutch. Females that laid only one clutch were smaller than those laying two or three clutches. Ovipo- sition frequency was 16.8-54.7 (mean = 30.4 ? 1.4) d between first and second clutches, and 18.6-32.1 (mean = 25.2 + 1.2) d between second and third clutches. Clutch size was 3-11 (mean = 5.0 ? 0.2) for first clutch and 2-6 for second (mean = 3.9 + 0.2) and third (mean = 4.0 + 0.3) clutches, and was positively correlated with female SVL. Although there was a trade-off between egg mass and the total number of eggs produced per season, eggs from first clutches were larger than eggs from subsequent clutches. In all three clutches, an increase in egg mass was accommodated by a decrease in egg length. There were both among clutch and among individual variation in clutch size and among clutch variation in egg mass, but no individual de- pendence of egg mass was found.