Feeding and foraging ecology of Trindade petrels Pterodroma arminjoniana during the breeding period in the South Atlantic Ocean

Leal, G. R., Furness, R. W., McGill, R. A.R. , Santos, R. A. and Bugoni, L. (2017) Feeding and foraging ecology of Trindade petrels Pterodroma arminjoniana during the breeding period in the South Atlantic Ocean. Marine Biology, 164, 211. (doi: 10.1007/s00227-017-3240-8)

Abstract

Seabirds breeding in tropical environments experience high energetic demands, when foraging in an oligotrophic environment. The globally threatened Trindade petrel Pterodroma arminjoniana has its largest colony in Trindade Island (20°30′S–29°19′W) inside the oligotrophic South Atlantic Subtropical Gyre. Diet sampling methods, geolocator tracking and stable isotope analysis were used to describe its diet, compare foraging trips and distributions, and assess temporal variations in the trophic niche throughout the breeding period. Diet consisted mainly of squid and fish. The high species diversity and wide range of prey sizes consumed suggests the use of multiple foraging techniques. Stable isotope mixing models confirm that Trindade petrels rely mainly on squid throughout the breeding period. Its broad isotopic niche seems to reflect both a diverse diet and foraging range, since birds can reach up to 3335 km from the colony. Isotopic niche showed limited variation even in an 8-year interval, apparently due to oceanographic stability, although changes in the isotopic niche have demonstrated an adjustment to different conditions in different seasons. Petrels change foraging areas and prey during the breeding period: pre-incubating birds use more productive areas west of Trindade Island and obtain low trophic position prey; incubating petrels perform longer trips southward to consume prey of high trophic position; and chick-rearing petrels use areas around the island. These results demonstrate that to deal with high demand breeding in a colony surrounded by oligotrophic waters, Trindade petrels need to explore wide foraging areas and utilize a diverse diet, besides adjusting trophic niche according to breeding stage.

• Item Type: Articles
• Additional Information: This project had been funded by Natural Environment Research Council (NERC-UK, Grant Number EK81-07/05) and the Brazilian National Research Council (CNPq, Grants 557152/2009-7 and 405555/2012-1.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McGill, Dr Rona and Furness, Professor Robert
• Authors: Leal, G. R., Furness, R. W., McGill, R. A.R., Santos, R. A., and Bugoni, L.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre; College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Marine Biology
• Publisher: Springer
• ISSN: 0025-3162
• ISSN (Online): 1432-1793
• Published Online: 23 October 2017
• Copyright Holders: Copyright © 2017 Springer-Verlag GmbH Germany
• First Published: First published in Marine Biology 164:211
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher