Decreased Survival of pink-footed Geese Anser brachyrhynchus Carrying Shotgun Pellets

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.