Effects of neck collars and radiotransmitters on survival and reproductionof emperor geese

Neck collars have been used widely for studies of goose population biology. Despite concerns about their negative impacts, few studies have employed d esigns capable of clearly demonstrating these effects. During a 1993-98 stu dy of emperor geese (Chen canagica), we contrasted survival and reproductio n of geese marked with tarsal bands to those marked with either small neck collars, large neck collars, or small neck collars with attached radiotrans mitters, Annual survival of adult females marked with tarsal bands varied a mong years and averaged 0.807 +/- 0.140 ((x) over bar +/- 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 bir ds were similar to those for unmarked birds, other markers reduced clutch s izes by about 1 egg Egg mass and hatch date were not affected by marker typ e. Future studies of goose demographics should seriously consider use of al ternative markers.