The effect of age, sex and winter severity on return rates and apparent survival in the Common Kingfisher Alcedo atthis
Abstrakt
Survival is a major life history trait known to be age- and/or sex-specific in many bird species. Regardless of age and sex, the survival of resident birds can be reduced by high mortality during harsh winters.
In this study, we used mark-recapture data collected during 2014-2018 to assess return rates and apparent survival in relation to age, sex and winter severity in two Common Kingfisher Alcedo atthis populations from Slovakia and the Czech Republic. During five seasons, we ringed a total of 2261 Kingfishers, 353 adults and 1908 nestlings, which yielded 85 recaptures.
In total, we recaptured 13.0% of birds ringed as adults (17.5% males, 8.2% females) and 0.8% of those ringed as nestlings (0.7% males, 0.1% females). Surviving adults returned to the previously used nesting hole in 87.0% of cases.
Young birds never returned to the hole where they hatched. Breeding dispersal was significantly shorter than natal dispersal.
Returned birds started to breed significantly earlier in the year of their return than in the previous year, but breeding success did not vary between these years. Estimated values of apparent survival were quite low, varied annually, and were negatively affected by winter severity.
Males did not differ in apparent survival from females, but adults survived better than juveniles. We discuss the difference in apparent survival between the age categories by varying degrees of site fidelity/philopatry and different mortality rates.