0000000000024787
AUTHOR
Peter Blums
Sources of variation in survival and breeding site fidelity in three species of European ducks
Summary 1 We used long-term capture–recapture–recovery data and a modelling approach developed by Burnham (1993) to test a priori predictions about sources of variation in annual survival rates and fidelity within a population of individually marked females in three species of European ducks from a breeding ground study site in Latvia. 2 True annual survival was higher for diving ducks (tufted duck 0·72, common pochard 0·65) and lower for northern shoveler (0·52). Survival of female diving ducks was positively correlated with mean winter temperatures at Western European wintering areas, the relationship being much stronger for pochard. 3 We present the first unbiased estimates of breedin…
The occurrence of runt eggs in waterfowl clutches
Abstract Eggs that are abnormally small are called runt eggs, and they occur in clutches across a wide variety of bird species. We surveyed waterfowl researchers to determine the natural frequency of occurrence of runt eggs in wild nesting ducks, geese, and swans. Of 551,632 eggs examined, 215 were runts, yielding a frequency of 0.039%. They occurred at about four times this frequency (0.156% in 21,832 eggs) in a museum oological collection. Runt eggs were not significantly more common within any taxonomic group among wild waterfowl, and their occurrence was not related to the mean clutch size of a species or to whether waterfowl exhibited regular conspecific nest parasitism. Cavity-nesting…
Factors affecting breeding dispersal of European ducks on Engure Marsh, Latvia
Summary 1 We used up to 35 years of capture–recapture data from nearly 3300 individual female ducks nesting on Engure Marsh, Latvia, and multistate modelling to test predictions about the influence of environmental, habitat and management factors on breeding dispersal probability within the marsh. 2 Analyses based on observed dispersal distances of common pochards and tufted ducks provided no evidence that breeding success in year t influenced dispersal distance between t and t+ 1. 3 Breeding dispersal distances (year t to t+ 1) of pochards and tufted ducks were associated with a delay in relative nest initiation dates in year t+ 1. The delay was greater for pochards (c. 4 days) than for tu…
Correlates of lifetime reproductive success in three species of European ducks
Number of breeding attempts is a strong correlate of lifetime reproductive success (LRS) in birds, but the relative importance of potentially interacting factors affecting LRS has rarely been fully evaluated. We considered simultaneously five main factors hypothesized to influence LRS (age at first breeding, nesting date, number of breeding attempts, female traits, brood parasitism) by analyzing with path analysis 22-year data sets for 1,279 individually marked females and their offspring in tufted duck ( Aythya fuligula), common pochard ( A. ferina) and northern shoveler (Anas clypeata). We recaptured marked offspring as breeding adults (n=496 females) and obtained more complete estimates …
Estimating natal dispersal movement rates of female European ducks with multistate modelling
Summary 1 We used up to 34 years of capture–recapture data from about 22 100 new releases of day-old female ducklings and multistate modelling to test predictions about the influence of environmental, habitat and management factors on natal dispersal probability of three species of ducks within the Engure Marsh, Latvia. 2 The mean natal dispersal distances were very similar (c. 0·6–0·7 km) for all three species and were on average 2·7 times greater than breeding dispersal distances recorded within the same study system. 3 We were unable to confirm the kinship hypothesis and found no evidence that young first-nesting females nested closer to their relatives (either mother or sister) than to …
Effect of Incubation Body Mass on Reproductive Success and Survival of Two European Diving Ducks: A Test of the Nutrient Limitation Hypothesis
The nutrient limitation hypothesis postulates that variation in nutrient reserves during egg laying and incubation are important predictors of future reproductive success of female waterfowl. We tested one component of this hypothesis in two European diving ducks, Common Pochard (Aythya ferina) and Tufted Duck (Aythya fuligula), relating body masses of incubating females to subsequent nest success, and to duckling and adult survival. We based our analyses on 3,224 Common Pochards and 1,812 Tufted Ducks captured and weighed during the last two weeks before ducklings hatched at Engure Marsh, Latvia, in 1978-1993. Adult (ASY) females from successful nests weighed significantly more than those …