Divorce in the kittiwake gull rissa tridactyla

Abstract

Divorce has been observed in many species of bird. Studies have revealed a relationship between divorce and reproductive success. This study was carried out to investigate whether such a relationship exists in the Kittiwake (Rissa tridactyla). The aims were to determine when divorce occurs, what causes divorce to occur, what the effects of divorce on reproductive output are and, finally, why birds divorce. It was conducted at a warehouse on the north bank of the River Tyne in North Shields, Tyne & Wear, during the 1990 breeding season. Analysis of a long-term data set spanning thirty three years was also carried out. Divorce does cause a significant reduction in some measures of reproductive output, acting significantly during incubation. Divorce may be due to lower reproductive success in the preceding season, a possible result of incompatibility between individuals.