Survival of female black ducks, Anas rubripes, during the breeding season

The Mayfield method was used to estimate the survival rate of 19 radio-marked, female Black Ducks (Anas rubripes) in southcentral Maine during 1977-80. An overall survival rate of 0.74 was estimated for the 121-day monitoring period that included the pre-laying and laying, incubation, brood rearing, and post-rearing stages. No differences in survival rates were detected among these stages. Two instrumented hens were killed by Red-shouldered Hawks (Buteo lineatus) and a third was killed by an unknown predator. We found no evidence that the attachment of radio transmitters affected hen survival.