Sex-specific parental care by incubating Little Auks (Alle alle)

Abstract

The evolution of sex-specific reproductive behavior among species with biparental care promotes sexual conflict over care. Such conflict may be less intense in species with long-term pair bonds. We examined sex-specific patterns of care during the incubation period in a monogamous, colonially breeding seabird of the high Arctic region, the Little Auk (Alle alle). We recorded time spent by birds of known sex in-and outside the nest, and the frequency of particular activities (aggressive interactions and collection of nest material), during four continuous 24-h watches. Males and females shared the incubation duty equally. Both sexes participated in the off-incubation duty behavior with similar fre-quency. However, males attended nest-site territories more than females and were thus more often involved in aggressive interactions and nest-material collection. These results suggest that there were sex-specific patterns of engagement in different forms of parental care during the incubation period.