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Research article - Peer-reviewed, 2008

Survival estimates, mortality patterns, and population growth of Fennoscandian mallards Anas platyrhynchos

Gunnarsson, Gunnar; Elmberg, Johan; Dessborn, Lisa; Jonzen, Niclas; Poysa, Hannu; Valkama, Jari

Abstract

Long-term mallard capture-recapture data from Sweden and Finland were analyzed to describe temporal mortality patterns and reasons. We used program MARK and Seber models to estimate annual survival (S) and recovery (r) rates. Survival rates were used in a Monte Carlo simulation to evaluate the correspondence between observed and predicted annual population sizes of a Finnish sub-population. About 90% of recovered birds died from hunting. Most recoveries were from the hunting season, and more males than females were shot. Predation was the most common cause of natural mortality. Finnish capture-recapture data fitted best the global model in which survival and recovery vary with age and sex. Annual survival and recovery rates for adult and juvenile males and females were overlapping, ranging from 0.46 to 0.90 (survival) and 0.07 to 0.17 (recovery), whereas pulli had lower survival rates (0.21-0.42). Pulli that were successfully sexed at the time of ringing had higher recovery rates (female pulli: 0.23; male pulli: 0.32) than juveniles and adults. Density-dependent fledgling production was detected in the Finnish sub-population and was accounted for in the Monte Carlo simulation, which estimated predicted breeding population size quite well, although one of the observed annual values (2003) fell outside the 95% confidence limits.

Published in

Annales Zoologici Fennici
2008, volume: 45, number: 6, pages: 483-495

Authors' information

Gunnarsson, Gunnar
Swedish University of Agricultural Sciences, Department of Wildlife, Fish and Environmental Studies
Gunnarsson, Gunnar
Kristianstad University
Elmberg, Johan
Kristianstad University
Dessborn, Lisa
Swedish University of Agricultural Sciences, Department of Wildlife, Fish and Environmental Studies
Dessborn, Lisa
Kristianstad University
Jonzén, Niclas
Lund University
Pöysä, Hannu
Finnish Game and Fisheries Research Institute
Valkama, Jari
Finnish Museum of Natural History

UKÄ Subject classification

Ecology
Zoology

Publication Identifiers

DOI: https://doi.org/10.5735/086.045.0603

URI (permanent link to this page)

https://res.slu.se/id/publ/32054