Wendy L. Reed – Andrew M. Turner – Paul R. Sotherlland

Consequences of Egg-Size Variation in the Red-winged Blackbird

Abstract: Life-history theory predicts that as parents increase their investment in individual offspring, the survival rates of those offspring should also increase (Winker and Wallin 1987, Stearns 1992, Bernardo 1996). For oviparous taxa, Parental investment may be directed toward eggs or hatchlings. Birds are ideal organisms to test general hypotheses of parental investment owing to the substantial interspecific variation in relative investments made by parents toward eggs and hatchlings and because of the ability of researchers to isolate and quantify these investments. The altrical-percocial continuum, based on the development of young at hatching (Nice 1962), provides a convenient description of interspecific patterns in relative energy investment directed toward eggs versus hatched young.