Journal of Ornithology

, Volume 157, Issue 3, pp 861–873 | Cite as

Genetic and morphological sex identification methods reveal a male-biased sex ratio in the Ivory Gull Pagophila eburnea

  • Glenn Yannic
  • Thomas Broquet
  • Hallvard Strøm
  • Adrian Aebischer
  • Christophe Dufresnes
  • Maria V. Gavrilo
  • H. Grant Gilchrist
  • Mark L. Mallory
  • R. I. Guy Morrison
  • Brigitte Sabard
  • Roberto Sermier
  • Olivier Gilg
Original Article


Sex identification of birds is relevant to studies of evolutionary biology and ecology and is often a central issue for the management and conservation of populations. The Ivory Gull Pagophila eburnea (Phipps, 1774) is a rare high-Arctic species whose main habitat is sea ice throughout the year. This species is currently listed Near Threatened by the IUCN, because populations have drastically declined in part of the species distribution in the recent past. Here we tested molecular sexing methods with different types of samples. Molecular sexing appeared to be very efficient with DNA extracted from muscle, blood, and buccal swabs, both for adults and young chicks. We also performed morphological analyses to characterize sexual size dimorphism in Ivory Gulls sampled in three distinct regions: Greenland, Svalbard, and Russia. Males were larger than females for all morphometric measurements, with little overlap between sexes. Discriminant analysis based on six morphometric variables correctly classified ~95 % of the individuals, even when using two variables only, i.e., gonys height and skull length. Therefore, both molecular and biometric methods are useful for sexing Ivory Gulls. Interestingly, our results indicate a male-biased sex ratio across all Ivory Gull populations studied, including two samples of offspring (67.8 % males).


Molecular sexing Morphological sexing Sexual dimorphism Noninvasive sampling Buccal swab Arctic 


Genetische und morphologische Geschlechtsbestimmungsmethoden enthüllen ein zugunsten der Männchen verschobenes Geschlechterverhältnis bei der Elfenbeinmöwe Pagophila eburnea Die Bestimmung des Geschlechts hat Relevanz für Studien zur Evolutionsbiologie und Ökologie von Vögeln und ist oft von zentraler Bedeutung für Management und Schutz von Populationen. Die Elfenbeinmöwe Pagophila eburnea (Phipps, 1774) ist eine seltene hocharktische Vogelart, deren ganzjähriger Hauptlebensraum Meereis ist. Derzeit wird die Art bei der IUCN als potenziell gefährdet geführt, da es in der jüngeren Vergangenheit in Teilen ihres Verbreitungsgebietes zu drastischen Populationsabnahmen kam. Hier prüften wir molekulare Geschlechtsbestimmungsmethoden anhand verschiedener Probentypen. Die molekulare Geschlechtsbestimmung erwies sich als effizient für aus Muskelgewebe, Blut und Schnabelabstrichen gewonnener DNA, sowohl bei Adulten als auch bei kleinen Küken. Außerdem führten wir morphologische Analysen durch, um den geschlechtsspezifischen Größendimorphismus bei Elfenbeinmöwen aus drei verschiedenen Regionen, nämlich Grönland, Spitzbergen und Russland, zu charakterisieren. Bezüglich aller morphometrischen Maße waren die Männchen größer als die Weibchen und es gab nur geringe Überschneidungen zwischen den Geschlechtern. Diskriminanzanalysen auf der Grundlage von sechs morphometrischen Variablen konnten etwa 95 % der Individuen korrekt zuordnen, selbst wenn nur zwei der Variablen verwendet wurden, z. B. Gonyshöhe und Kopf-Schnabellänge. Daher eignen sich sowohl molekulare als auch biometrische Methoden zur Geschlechtsbestimmung bei Elfenbeinmöwen. Interessanterweise deuten unsere Ergebnisse ein zugunsten der Männchen verschobenes Geschlechterverhältnis über alle untersuchten Elfenbeinmöwenpopulationen hinweg an, darunter auch zwei Proben von Jungtieren (67,8 % Männchen).



We are grateful to Emmanuelle Pouivé, to the late John Lau (Station Nord), and to David Paetkau and collaborators (Wildlife Genetics International Inc.) for logistic assistance. We also thank Jacques Hausser for answering our questions regarding linear discriminant function analysis. We thank two anonymous referees for their comments on a previous version of this manuscript. This work was supported by grants from foundation Ellis Elliot (Switzerland), Société vaudoise des Sciences naturelles (Switzerland), and Nos Oiseaux (Switzerland) to GY, by a foundation Agassiz (Switzerland) grant to TB and by Nicolas Perrin’s research group (Department of Ecology and Evolution, University of Lausanne). Field work in Greenland was supported by the National Geographic Society, Prix Gore-Tex initiative, Fondation Avenir Finance, the Arctic Ocean Diversity Census of Marine Life Project, CNES, CLS, the Groupe de Recherche en Écologie Arctique (GREA), and F. Paulsen. The fieldwork in Norway and Russia was funded by the Norwegian Ministry of Environment, the Norwegian Polar Institute, Arctic and Antarctic Research Institute. The project was part of the work plan of the Joint Norwegian-Russian Commission on Environmental Protection. The work in Russia was part of the Russian IPY 2007/2008 program. Canadian fieldwork was supported by Environment Canada and Natural Resources Canada (PCSP). We thank the Commanding Officers and members of CFS Alert, as well as staff at the Environment Canada Weather Station at Alert, for this generous support.


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Copyright information

© Dt. Ornithologen-Gesellschaft e.V. 2016

Authors and Affiliations

  • Glenn Yannic
    • 1
    • 2
  • Thomas Broquet
    • 3
    • 4
  • Hallvard Strøm
    • 5
  • Adrian Aebischer
    • 2
  • Christophe Dufresnes
    • 6
  • Maria V. Gavrilo
    • 7
    • 8
  • H. Grant Gilchrist
    • 9
  • Mark L. Mallory
    • 10
  • R. I. Guy Morrison
    • 11
  • Brigitte Sabard
    • 2
  • Roberto Sermier
    • 6
  • Olivier Gilg
    • 2
    • 12
  1. 1.LECA - Laboratoire d’Ecologie Alpine - CNRS UMR 5553Université Savoie Mont BlancLe Bourget-Du-Lac CedexFrance
  2. 2.Groupe de Recherche en Ecologie Arctique (GREA)FranchevilleFrance
  3. 3.CNRS, Team Diversity and Connectivity of Coastal Marine LandscapesStation Biologique de RoscoffRoscoffFrance
  4. 4.UMR 7144, Station Biologique de RoscoffSorbonne Universités, UPMC Univ Paris 06RoscoffFrance
  5. 5.Norwegian Polar InstitutePolar Environmental CentreTromsöNorway
  6. 6.Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
  7. 7.National Park Russian ArcticArchangelskRussia
  8. 8.Joint Directorate of Taimyr Nature ReservesNorilskRussia
  9. 9.Environment Canada, National Wildlife Research Centre and Department of BiologyCarleton UniversityOttawaCanada
  10. 10.Acadia UniversityWolfvilleCanada
  11. 11.Environment Canada, Science and Technology Branch, National Wildlife Research CentreCarleton UniversityOttawaCanada
  12. 12.Laboratoire Biogéosciences, UMR CNRS 6282, Equipe Ecologie EvolutiveUniversité de BourgogneDijonFrance

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