Inter-Research > MEPS > v724 > p155-165  
Marine Ecology Progress Series

via Mailchimp

MEPS 724:155-165 (2023)  -  DOI:

Multi-colony tracking reveals segregation in foraging range, space use, and timing in a tropical seabird

Alice M. Trevail1,*,#, Hannah Wood2,#, Peter Carr2, Ruth E. Dunn3,4, Malcolm A. Nicoll2, Stephen C. Votier3, Robin Freeman2

1Environment & Sustainability Institute, University of Exeter, Penryn Campus, Penryn TR10 9FE, UK
2Institute of Zoology, Zoological Society of London, Regents Park, London NW1 4RY, UK
3The Lyell Centre, Heriot-Watt University, Edinburgh EH14 4AS, UK
4Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
*Corresponding author:
#These authors contributed equally to this work

ABSTRACT: Colonial animals experience density-dependent competition for food, which is posited to influence foraging range and lead to inter-colony segregation. However, such patterns are poorly studied in the tropics, where predictable day lengths, oligotrophic conditions, and facultative foraging may alter the relationships between foraging and intra-specific competition. Here, we GPS-tracked 207 breeding red-footed boobies Sula sula rubripes (RFB) from 4 neighbouring Chagos Archipelago colonies (~1100 to 9200 breeding pairs) in the central Indian Ocean, to determine how foraging strategies (i.e. effort, segregation, and timing) vary with colony, while accounting for sex, monsoon season, stage of reproduction, year, and individual. During incubation and chick-rearing, RFBs commute to pelagic foraging grounds (maximum distance mean ± SE: 112.9 ± 3.7 km; total distance: 298.4 ± 6.2 km) over 1 to 5 d (18.5 ± 1.6 h). Foraging effort was highest at the largest colony, and greater among females than males. Departure angles varied among colonies, leading to foraging areas that were largely spatially segregated. Timing of departures and arrivals were strongly constrained by daylight hours, although females and birds at the largest colony left earliest. Our study highlights the importance of inter-colony differences in tropical seabird foraging, which may relate to different levels of intra-specific competition. Moreover, links between foraging times and colony size suggest a previously undescribed outcome of density-dependent competition, highlighting the importance of understanding colonial living across multiple dimensions.

KEY WORDS: Central-place foraging · Sula sula rubripes · Red-footed booby · Distributions · Indian Ocean · GPS tracking

Full text in pdf format
Supplementary Material
Cite this article as: Trevail AM, Wood H, Carr P, Dunn RE, Nicoll MA, Votier SC, Freeman R (2023) Multi-colony tracking reveals segregation in foraging range, space use, and timing in a tropical seabird. Mar Ecol Prog Ser 724:155-165.

Export citation
Share:    Facebook - - linkedIn

 Previous article Next article