Neck collars have been used widely for studies of goose population biology. Despite concerns about their negative impacts, few studies have employed designs capable of clearly demonstrating these effects. During a 1993-98 study of emperor geese (Chen canagica), we contrasted survival and reproduction of geese marked with tarsal bands to those marked with either small neck collars, large neck collars, or small neck collars with attached radiotransmitters. Annual survival of adult females marked with tarsal bands varied among years and averaged 0.807 ?? 0.140 (v?? ?? SE). Survival of geese with other types of markers also varied among years but was lower (0.640 ?? 0.198). Collars with radiotransmitters lowered breeding propensity, as indexed by resighting rates. Although clutch sizes of tarsal banded birds were similar to those for unmarked birds, other markers reduced clutch sizes by about 1 egg. Egg mass and hatch date were not affected by marker type. Future studies of goose demographics should seriously consider use of alternative markers.
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Effects of neck collars and radiotransmitters on survival and reproduction of emperor geese