Survival of Common Goldeneye Ducklings in Interior Alaska

Abstract

Duckling survival is an important component of waterfowl population dynamics, and we provide the first-known estimates of duckling survival for common goldeneyes (Bucephala clangula) at the northern limit of their range in Interior Alaska. We color-marked common goldeneye ducklings from 91 broods and radio-marked a subset of the females (n = 39) from a nest-box population in the boreal forest during the summers of 2002 and 2003. We monitored 46 broods in 2002 and 2003 combined and estimated daily survival rates (DSR) and survival to 30 days of age using program MARK. We modeled DSR in relation to year, linear trend across season, duckling age, female age, female body condition, initial brood size, and daily precipitation. Model-averaged duckling survival estimates from the mean yearly hatch date to 30 days of age were 0.64 (95% CI, 0.37–0.90) and 0.67 (95% CI, 0.54–0.80) for 2002 and 2003, respectively. Our best-approximating model indicated that survival differed by year and increased in a linear manner over the course of the 2002 season. Precipitation had a consistent negative effect on duckling survival in both years across models, whereas duckling age did not explain much of the variation in daily survival rates. In light of the decline of many populations of sea ducks, we suggest that more effort should be expended to obtain estimates of other population parameters for common goldeneyes, and monitoring programs should attempt to estimate populations more precisely to identify population-level changes in the future.