The influence of mating systems on philopatry: a test with polyandrous red-necked phalaropes

Abstract

Sex differences in philopatry have been linked to competition for mates and resources (Greenwood 1980, Anim. Behav. 28, 1140–1162). Philopatry and nest-site fidelity of red-necked phalaropes, Phalaropus lobatus, were examined to determine the importance of a polyandrous mating system and lack of territoriality. Over a 5-year period, natal philopatry was strongly male biased, with 23 males and five females returning, out of 555 colour-banded chicks. This bias is consistent with predicted benefits to males from experience with the area for brood-rearing, and a lack of territorial defence by females. However, adult return rates did not differ significantly by sex, with 38% of males and 34% of females returning (of 177 males and 84 females that were banded). There was also no significant difference between the sexes in distances moved between nest sites within the study area. Movements by males renesting within a year (following nest predation) were significantly greater than inter-year distances, and yearlings moved significantly farther than adults between years. Overall, the results support the role of mating systems in natal philopatry, but the distinction between mate and territory defence is not sufficient to account for the high return rates of adult females. Although females do not defend territories, experience with home ranges may facilitate mate competition.