Title
Sex-specific effects of wind on the flight decisions of a sexually dimorphic soaring bird
Date Issued
01 August 2020
Access level
open access
Resource Type
journal article
Author(s)
Clay T.A.
Weimerskirch H.
Phillips R.A.
den Ouden O.
Basille M.
Clusella-Trullas S.
Assink J.D.
Patrick S.C.
University of Florida
Publisher(s)
Blackwell Publishing Ltd
Abstract
In a highly dynamic airspace, flying animals are predicted to adjust foraging behaviour to variable wind conditions to minimize movement costs. Sexual size dimorphism is widespread in wild animal populations, and for large soaring birds which rely on favourable winds for energy-efficient flight, differences in morphology, wing loading and associated flight capabilities may lead males and females to respond differently to wind. However, the interaction between wind and sex has not been comprehensively tested. We investigated, in a large sexually dimorphic seabird which predominantly uses dynamic soaring flight, whether flight decisions are modulated to variation in winds over extended foraging trips, and whether males and females differ. Using GPS loggers we tracked 385 incubation foraging trips of wandering albatrosses Diomedea exulans, for which males are c. 20% larger than females, from two major populations (Crozet and South Georgia). Hidden Markov models were used to characterize behavioural states—directed flight, area-restricted search (ARS) and resting—and model the probability of transitioning between states in response to wind speed and relative direction, and sex. Wind speed and relative direction were important predictors of state transitioning. Birds were much more likely to take off (i.e. switch from rest to flight) in stronger headwinds, and as wind speeds increased, to be in directed flight rather than ARS. Males from Crozet but not South Georgia experienced stronger winds than females, and males from both populations were more likely to take-off in windier conditions. Albatrosses appear to deploy an energy-saving strategy by modulating taking-off, their most energetically expensive behaviour, to favourable wind conditions. The behaviour of males, which have higher wing loading requiring faster speeds for gliding flight, was influenced to a greater degree by wind than females. As such, our results indicate that variation in flight performance drives sex differences in time–activity budgets and may lead the sexes to exploit regions with different wind regimes.
Start page
1811
End page
1823
Volume
89
Issue
8
Language
English
OCDE Knowledge area
Zoología, Ornitología, Entomología, ciencias biológicas del comportamiento
Ecología
Subjects
Scopus EID
2-s2.0-85087169924
PubMed ID
Source
Journal of Animal Ecology
ISSN of the container
00218790
Sponsor(s)
We are grateful to all those involved in data collection at Possession Island and Bird Island, in particular Hannah Froy for considerable assistance with GPS tracking. We thank Dominique Fillipi for developing the X‐GPS loggers, Jeff Zeyl and Emiel van Loon for useful discussions, Andy Wood, Karine Delord and Dominique Besson for database support and the European Centre for Medium Range Weather Forecasts (ECMWF) for making modelled wind data available. We would also like to thank the two anonymous reviewers for their constructive comments, which helped improve the manuscript. The Institut Polaire Français and the Terres Australes Antarctique Françaises (TAAF) provided logistical and financial support at the Crozet Islands. T.A.C., S.C.P., R.J., S.C.T., M.B., O.d.O. and J.A. were funded by a Human Frontier Science Program Young Investigator Grant (SeabirdSound; RGY0072/2017). This study represents a contribution to the Ecosystems component of the British Antarctic Survey Polar Science for Planet Earth Programme, funded by NERC.
Sources of information:
Directorio de Producción Científica
Scopus