The Relationship between Reproduction and Survival in Known-Aged California Gulls

摘要: Survival from 1984 to 1985 was compared among known-aged California Gulls 4-23 yr old. Data supported a hypothesis of increasing reproductive effort with age. A flood during terminated breeding the incubation phase part colony, thus permitting an estimate costs. Yearly survival gulls whose nest flooded 92% 72% that carried out cycle. Adult inversely related level fledging success in 1984. declined and increased However, differing ages within same category had probability survival. No evidence age because disproportionately larger numbers individuals "good phenotypes" survived old Cross-sectional data showed peaked at 16-19 20-23, suggesting senescence extremely gulls. longitudinal indicated did not decline The few surviving extreme so by consistently exerting low offspring.