A key to ageing goslings of the Hawaiian Goose Branta sandvicensis

Abstract

The pattern of feather emergence in the goslings of captive Hawaiian Geese, or Nene, was photographed and scored visually to provide a guide for ageing goslings in the wild. The mean age at fledging was 68 days (range 58-77) and the mean age at which the juveniles took on an adult appearance was 137 days (range 199-150). The ability to determine the age of Nene goslings will enable field researchers to keep track of wild broods, thus allowing reliable assessments of recruitment, mortality and population size.