Sex differences in breeding colony fidelity of house martins delichon urbica

Abstract

At nine House Martin colonies in Cambridgeshire and Norfolk, over an eleven year period, 19.2% of adult birds and 7.4% of juvenile birds are shown to return in subsequent years. 63.6% of these adults and 85.7% of these first year birds are male. This information is used to calculate maximum mortality rates for adult and first year birds. © 1990 Taylor & Francis Group, LLC.