Territory acquisition and mating success in pheasants, Phasianus colchicus: an experiment

Abstract

Abstract. In a field experiment, the territorial establishment of male pheasants in the Revinge area of southern Sweden was manipulated. This was done to estimate the influence of male-male competition for high quality territories on the males' prospective attraction of females. A collateral of the experiment was to evaluate whether differences in male spur length affected the males' ability to establish and maintain territories. Two groups of wild male pheasants with different average spur length, but otherwise similar in body measurements and age distribution, were compared regarding territoriality and attraction of females. By an earlier release from the over-wintering enclosure, the short-spurred birds were allowed to establish territories 3 weeks ahead of the long-spurred ones. Significantly fewer males of the long-spurred group established a territory compared with the short-spurred group. Furthermore, the short-spurred males' home-range locations were not affected by the proximity to males of the long-spurred group. In only one case out of 14 did a male from the long-spurred group succeed in seizing a territory from a male in the short-spurred group. The two groups of males did not differ significantly in attraction of females. This result remained unchanged after controlling statistically for differences in spur-length between the two groups.