Amat J.A., Fraga R.M. & Arroyo G.M. (2001) Variations in body condition and egg characteristics of female Kentish Plovers Charadrius alexandrinus. ARDEA 89 (2): 293-299

Offspring size is a very important life-history trait that may be affected by maternal effects and environmental conditions. We studied variation in egg size and within-clutch symmetry variation in egg volume in Kentish Plovers Charadrius alexandrinus in southern Spain over six years. Repeatability of egg volume among years was high. Repeatability of egg volume between clutches laid by individual females within a breeding season was also high. Repeatability of within-clutch egg size symmetry was low and not significant. Mean egg volume was correlated with indexes of both structural body size and body condition of females. The body masses of females showed consistency between years. Females in better condition were more able than females in lower body condition of laying not only larger eggs, but also eggs of more similar size. As we previously found that, within clutches, heavier chicks survived better than their lighter siblings, a higher body condition confers, through its effects on egg characteristics, a clear fitness advantage