The Adaptive Significance of Egg Size and Laying Date in Thick‐Billed Murres Uria Lomvia

The effect of egg size and laying date on the fledging mass of Thick—Billed Murre chicks was examined at Cape Hay, Bylot Island, and Coburg Island, Northwest Territories, Canada, to test the idea that late—laying females face a trade—off between the time of egg laying and egg size. There was a seasonal decline in egg volume, and egg volume was correlated with mass and size (wing length) of chicks soon after hatching. Partial correlations showed...