Effects of plastic neck collars on the behaviour and breeding performance of geese and their value for distant recognition of individuals

Johnson, I. P. & Sibly, R. M. 1989. Effects of plastic neck collars on the behaviour and breeding performance of geese and their value for distant recognition of individuals. Ring. & Migr. 10: 58–62. Neck collars made from ‘Vynalast’, a thermoplastic engraving laminate, were fitted to 165 Canada Geese in southern England during 1982–1984. The collars, each engraved with a unique two-letter code, could be used to identify individuals at distances of up to 500 m. The behaviour of the geese was not adversely affected by the collars, with collared and uncollared birds having very similar time budgets. Breeding success tended to be higher in collared than in uncollared birds, but this can be attributed to the greater age and experience of collared individuals. The retention rate was 76.3% for the first year, with 55.5% of collars being retained for two years. It is concluded that such collars are ideal for intensive short-term studies of large waterfowl (swans and geese), where it is necessary to identify larg...