Madsen, J. & Noer, H. 1996: Decreased survival of pink-footed geese Anser brachyrhynchus carrying shotgun pellets. - Wildl. Biol. 2: 75-82.
Pink-footed geese Anser brachyrhynchus caught during March-April 1990-1992 in western Jutland, Denmark, were examined for shotgun pellets by X-ray photography, marked by individual colour neck-bands and released. Based on resightings during 1991-1995, survival rates of pellet carriers (N = 114) and non-carriers (N = 230) were compared. Annual resighting probabilities were more than 99%, resulting in a high precision of survival rate estimates. No indications of differences in survival between sexes or age classes (first-year and older) were found, but pellet carriers had a significantly lower survival (0.765) than non-carriers (0.869), this difference being constant between years and cohorts. Since pellet carrying individuals could theoretically represent a non-random subset of the population, this is not conclusive evidence that infliction of pellets affects survival. The lower survival affects the frequency of adult pellet carriers found in X-ray samplings. Correcting for this, the evidence strongly suggests that pellets are inflicted upon at least 0.7 goose for each bagged one.
Key words: pink-footed geese, survival, hunting, shotgun pellets, capture-recapture
Jesper Madsen & Henning Noer, National Environmental Research Institute, Department of Coastal Zone Ecology, Kalø, Grenaavej 12, DK-8410 Rønde, Denmark
Received 29 May 1996, accepted 12 September 1996
Associate Editor: Nigel G. Yoccoz