Genetic structuring among colonies of a pantropical seabird: Implication for subspecies validation and conservation

Research output: Contribution to journalArticlepeer-review

Authors

  • Laurence Humeau
  • Matthieu Le Corre
  • Colin Wearn
  • Janos C. Hennicke
  • James C. Russell
  • Yann Gomard
  • Hélène Magalon
  • Patrick Pinet
  • Pauline Gélin
  • François Xavier Couzi
  • Etienne Bemanaja
  • Vikash Tatayah
  • Bacar Ousseni
  • Gérard Rocamora
  • Patrick Talbot
  • Nirmal Shah
  • Leandro Bugoni
  • Denis Da Silva
  • Audrey Jaeger

Colleges, School and Institutes

External organisations

  • Université de La Réunion
  • Centre for Ornithology
  • Army Ornithological Society (AOS)
  • Royal Air Force Headquarters
  • University of Hamburg
  • Centre d'Etudes Biologiques de Chizé
  • University of Auckland
  • Parc National de La Réunion
  • Société d'Etudes Ornithologiques de La Réunion (SEOR)
  • Centre National de Recherches Océanographiques (CNRO)
  • Mauritian Wildlife Foundation
  • GEPOMAY
  • Island Conservation Society
  • University of Seychelles
  • Bermuda Zoological Society
  • Nature Seychelles
  • Universidade Federal do Rio Grande

Abstract

Investigations of the genetic structure of populations over the entire range of a species yield valuable information about connectivity among populations. Seabirds are an intriguing taxon in this regard because they move extensively when not breeding, facilitating intermixing of populations, but breed consistently on the same isolated islands, restricting gene flow among populations. The degree of genetic structuring of populations varies extensively among seabird species but they have been understudied in their tropical ranges. Here, we address this across a broad spatial scale by using microsatellite and mitochondrial data to explore the population connectivity of 13 breeding populations representing the six subspecies of the white-tailed tropicbird (Phaethon lepturus) in the Atlantic, Indian, and Pacific Oceans. Our primary aim was to identify appropriate conservation units for this little known species. Three morphometric characters were also examined in the subspecies. We found a clear pattern of population structuring with four genetic groups. The most ancient and the most isolated group was in the northwestern Atlantic Ocean. The South Atlantic populations and South Mozambique Channel population on Europa were genetically isolated and may have had a common ancestor. Birds from the Indo-Pacific region showed unclear and weak genetic differentiation. This structuring was most well defined from nuclear and mtDNA markers but was less well resolved by morphological data. The validity of classifying white-tailed tropicbirds into six distinct subspecies is discussed in light of our new findings. From a conservation standpoint our results highlight that the three most threatened conservation units for this species are the two subspecies of the tropical North and South Atlantic Oceans and that of Europa Island in the Indian Ocean.

Bibliographic note

Funding Information: We thank Nature Seychelles, the Island Conservation Society and Bird Island Lodge (M. France and G. Savy) for their permission and support of the fieldwork on Cousin, Aride and Bird islands, respectively. We thank the University of Birmingham and the Ascension Island Government for granting research permits to work on birds on Ascension Island. JCH thanks the Christmas Island National Park for supporting the fieldwork. During fieldwork, JCH was funded by a Marie Curie Research Fellowship from the European Union (PIEF-GA-2009-236295). The authors wish to thank K. Chaussalet and Y. Szorlich for their assistance in genetics analysis, and the Gentyane Plateform (Clermont-Ferrand, France) for microsatellite genotyping. R. Bowie, T. Burg and an anonymous referee provided helpful comments on the manuscript. C. Lebarbenchon assisted with work on phylogenetic analyses and molecular clocks. This research was supported by the FRROI Core-Divgen 2008/2009 and the F?d?ration Biodiversit? et Sant? et Zone Tropicale BIOST (Universit? de La R?union), the FEDER ?Pathogenes associ?s ? la Faune Sauvage Oc?an Indien? (Programme Op?rationnel de Coop?ration Territoriale 2007-2013; #31189) and by the CNRS - INEE/TAAF (AAP Iles Eparses ?OMABIO? project). LB received CNPq Grant PQ #311409/2018-0. Publisher Copyright: © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

Details

Original languageEnglish
Pages (from-to)11886-11905
Number of pages20
JournalEcology and Evolution
Volume10
Issue number21
Publication statusPublished - 29 Sep 2020

Keywords

  • conservation status, genetic structure, Phaethon lepturus, subspecies status