The effect of mate change and new partner's age on reproductive success in the barnacle goose, Branta leucopsis

• Published in: Behavioral Ecology
• Main Authors: Forslund, Pär, Larsson, Kjell
• Format: Text
• Language: English
• Published: Oxford University Press 1991
• Subjects: Articles; Barnacle goose; Branta leucopsis
• Online Access: http://beheco.oxfordjournals.org/cgi/content/short/2/2/116; https://doi.org/10.1093/beheco/2.2.116

Mate retention frequencies and correlations between mate change and reproductive performance were estimated in a population of barnacle geese, Branta leucopsis , breeding on the island of Gotland in the Baltic. About 90% of the pairs remained together from one breeding season to the next. Only 2.4% of the pairs divorced, most mate changes being consequences of the death of one partner. Divorces were not forecast by low reproductive success, and seemed to be accidental. In the season before mate change, there was no difference in reproductive performance, measured as clutch size, hatching date, and number of fledged young, between faithful pairs and pairs where one partner was subsequently changed. However, in the first season with a new partner, clutch size and number of fledged young decreased on average. Hence, because mate change led to a reduction in reproductive success, it was concluded that mate retention is advantageous. Our results suggest that this reduction is more likely due to the lower average age or breeding experience of new partners than to the benefits of breeding experience with one particular partner. [Behav Ecol 1991 ;2:116–122]