MATE SAMPLING AND COPULATION BEHAVIOR OF GREAT SNIPE FEMALES

Mate sampling by great snipe, Gallinago media, was studied by following individually marked females on their visits to two leks in five consecutive mating seasons. The main objectives were to determine whether the females used a sequential search or a best-of-N-males comparison when selecting a mating partner, and to evaluate the consequences of females engaging in copulations with more than one male and in repeated copulations with the same male. The minimum length of the period between the first observation of a female and her first observed copulation varied from 0 to 18 days (median 4). One to 10 males (median=2) were visited in the pre-mating period. Nineteen females (58%) mated on their first observed visit to the territory of a male, whereas 14 (42%) returned to a previously visited male to mate. Seven (21%) of the females were seen copulating on more than one night, and four of them changed copulation partner between nights. The fact that so many females were seen returning to a previously visited male to mate is best explained by a best-of-N-males comparison, but the results could also be explained by a sequential search strategy with a variable threshold. Females copulated more with successful males and they copulated more when other females were present on the territory of the male than when alone. Competition between females is most likely to account for these differences, but the mechanism is not known. The testes of great snipe males were large compared with those of other waders, indicating that sperm competition is important in this lekking species.