Age differences in the dispersal behaviour of robins erithacus rubecula studied by counting wing spots

Abstract

The yellowish spots on the greater wing-coverts of Robins were counted in 487 individuals captured near Pisa, Italy, between October and March 1976 to 1980. The results obtained confirm that the number of spots is lower in adults than in young birds and tends to diminish during moults. Although the number of spots cannot be used to determine the age of an individual, it can be utilized to examine differences in some aspects of behaviour between adult and young Robins, and is especially useful in periods in which other criteria for ageing are not available. Differences were found in the mean number of spots in birds captured in various periods, and between those which did and did not home after displacement; these data infer differences in migratory behaviour between adult and young Robins, and show that adult Robins have a stronger site attachment and homing success than juveniles. © 1983 Taylor & Francis Group, LLC.