Partner intrinsic characteristics influence foraging trip duration, but not parental care coordination in wandering albatrosses (Diomedea exulans)

Abstract

**Abstract:** Foraging trip duration is an important mediator of fitness in seabirds. Many species coordinate their trip duration, but how this coordination varies across individuals, or drivers of the trip duration itself are not fully resolved. Age has been shown to affect coordination strength in some seabird species, but the influence of other intrinsic variables, such as personality remain understudied. Furthermore, studies examining whether individual or partner traits set the pair trip duration are lacking. Here we examined the role that boldness and age play in determining individual foraging trip duration and pair coordination exhibited by wandering albatrosses (Diomedea exulans). Saltwater immersion loggers collected foraging trip durations across incubation and brooding periods from one member of 71 pairs on the Crozet archipelago. Foraging trip duration was modelled with personality (human approach testing boldness), age of both partners and partner's previous trip duration. Parental coordination was stronger during incubation when compared with brooding, but it was not influenced by any intrinsic variables in either breeding stage. Surprisingly, individual foraging trip duration during incubation was mainly driven by partner intrinsic characteristics, with birds paired to older and bolder partners taking shorter foraging trips. During brooding, increased boldness of the individual and their partner led to shorter foraging trips but there was no effect of age. Contrary to many predictions, these results suggest that the partner's capacity or willingness to remain on the nest is the major driver of foraging trip duration and they highlight the importance of modelling pair behaviour. **Authors:** Fionnuala McCully¹, Henri Weimerskirch², Stephen Cornell¹, Benjamin Hatchwell³, Patrick Samantha¹ ¹University of Liverpool, ²Centre d'Etudes Biologiques de Chizé (CNRS & La Rochelle Université), ³University of Sheffield