Sources of variation in survival and breeding site fidelity in three species of European ducks

Abstract

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 breeding fidelity and permanent emigration in European ducks. Estimated fidelity rates were high (0·88 -1·0) and emigration rates low (0-0·12) for all three species, and we found strong evidence for age-specific differences in fidelity of pochards. Unusual long-distance (up to 2500 km) breeding dispersal movements that we found in female tufted ducks have not been documented in any other European waterfowl and are most probably a result of saturated nesting habitats. 4. Fidelity was a function of patch reproductive success in the previous year for all three species providing support for the idea that patch success is an important cue influencing fidelity. 5. Fidelity probability increased to 1·0 for shovelers during the last 12 years of study following provision of critical improvements in nesting habitats and suggested that habitat conditions and reproductive success determined site fidelity and settling patterns for shoveler and probably also influenced fidelity of the two other species. In predictable habitats, fidelity is a parameter that reflects the integration of fitness components and is thus a good quantity for assessing the effectiveness of habitat management actions.

Demographic effects of extreme winter weather in the barn owl

“…Using random effects models, our estimates of the long-term variance in survival are not confounded by sampling variance. Few other avian studies report estimates of demographic rates for more than 20 years (Peach et al 1994;Frederiksen and Bregnballe 2000;Blums et al 2002;Franklin et al 2002;Loison et al 2002;Robinson et al 2004). Franklin et al (2002) and Loison et al (2002) give estimates of temporal variance in survival corrected for sampling variance.…”

Individual quality, survival variation and patterns of phenotypic selection on body condition and timing of nesting in birds

“…Because we tend to think of fidelity as a characteristic of ducks that reproduce successfully and are generally fit (e.g., Johnson et al 1992;Blums et al 2002b), we predicted the same directional relationships between the two covariates and fidelity as with survival. However, we expected the evidence to be weaker because fidelity was relatively high in these species (Blums et al 2002b), leaving relatively little variation to explain.…”

“…The focus of this paper is on annual survival probability, but the capture-recapture models that we employ also estimate fidelity, the probability that a bird alive in a particular spring does not permanently emigrate outside the study area (see Blums et al 2002b). Because we tend to think of fidelity as a characteristic of ducks that reproduce successfully and are generally fit (e.g., Johnson et al 1992;Blums et al 2002b), we predicted the same directional relationships between the two covariates and fidelity as with survival.…”

Survival rates and blood metal concentrations in two species of free‐ranging North American sea ducks

“…Nevertheless, apparent survival can be considered as a minimal estimate of true survival. Moreover, female ducks, including scoters and eiders, are highly philopatric to breeding areas and often nest within a few kilometers or less of previous nest sites [21][22][23]; thus, the bias resulting from permanent emigration likely was negligible.…”