Sex Differences in Reproductive Behavior of Atlantic Puffins

Abstract

Female Atlantic Puffins (Fratercula arctica) incubated eggs longer and fed chicks more often than males, whereas males spent more time maintaining and defending the nesting burrow. Although time together was greatest during the pre-laying period, pair members were apart most of the time, suggesting limited mate guarding. Males attempt extra-pair copulations, but because copulations occurred on the water where females can dive to escape, copulations were never forced and may have been successful only between mates. These data suggest that the paired female's ability and willingness to prevent mating with additional males may be important in the evolution of mate guarding. Sex differences in time budgets and male mating attempts were consistent with suggestions that even with shared parental care in monogamous species, females invest more in direct care of the young (parental effort), while males invest more in territorial defense and attempted extra matings (mating effort).