Vocal interactions of breeding partners predict duration of incubation bout in an Artic seabird

Abstract

In species with biparental care, coordination of parental activities can have important fitness consequences. However, specific behavioral mechanism allowing the coordination of breeding partners remains largely unexplored. Prevalence of biparental care in seabirds makes this group particularly interesting for investigation of behavioral underpinnings of parental coordination. Here, we examined vocal behavior at the nest site of breeding partners and its role in shaping their parental share during incubation in the little auk (Alle alle). We evaluated two hypotheses related to the mechanisms involved in parental coordination: (1) behavioral adjustment, where a parent adjusts its effort according to the preceding effort of its partner and (2) vocal negotiation, where effort is adjusted based on information exchanged during the preceding vocal interaction. We found that little auk partners equally share their incubation time, although, duration of nest attendance is highly variable. No immediate reciprocity between partners in the time allocated to parental activity was observed as predicted by behavioral adjustment. However, nest attendance appeared to be related to the vocal interaction between partners during turn-taking. The duration of a given attendance was positively associated to the pair’s vocal activity and amount of vocal overlap occurring during turn-taking at the nest. Our results suggest a role of vocalization for coordinating between breeding pairs, providing a potential mechanism for the communication of information enabling this complex interaction.