Variation in Egg Dimensions in a Hooded Crow

Variation in egg size and shape of the Hooded Crow Corvus corone cornix was investigated in the National Park “Ujœcie Warty”, western Poland, in 2000 and 2001. Mean clutch size was 4.55±0.79 (n=40). Coefficients of variation for clutch means ranged from 2.00±1.16 (breadth) to 3.35±1.76 (elongation index). Mean repeatability estimates were 0.69, 0.71, 0.73, and 0.62 for length, breadth, volume, and elongation index, respectively. The results suggest that in the population studied, one should expect a relatively high heritability of egg dimensions and thereby a low influence of environmental conditions. This can be connected with the food storage ability in corvids.