Life histories of birds: clutch size, longevity, and body mass among North American game birds

Abstract

Clutch size, longevity, and body mass data for 54 North American game birds were extracted from the literature to test the hypothesis that a trade-off exists between fecundity and survival among avian species. Species with larger clutch sizes live shorter lives than species with smaller clutch sizes (r = −0.38, n = 54, P < 0.01). This relationship still holds when the effects of body mass are removed (r = −0.34, 51 df, P < 0.05), indicating that the relationship is not simply a function of body mass. This latter finding is inconsistent with previous life-history studies, perhaps because previous researchers did not attempt to remove body mass effects from their life-history investigations. Results are similar (P < 0.05) when mean values of life-history traits are examined at the generic level. However, no relationships (P > 0.05) among mean values of life-history traits occur at any taxonomic level higher than genus or when species are grouped with respect to feeding habits. This might be the result of low sample size. I conclude that the evolution of clutch size is influenced by longevity, or vice versa, among species and genera of North American game birds.