Oecologia

, Volume 168, Issue 1, pp 119–130

Foraging segregation and genetic divergence between geographically proximate colonies of a highly mobile seabird

  • Anne E. Wiley
  • Andreanna J. Welch
  • Peggy H. Ostrom
  • Helen F. James
  • Craig A. Stricker
  • Robert C. Fleischer
  • Hasand Gandhi
  • Josh Adams
  • David G. Ainley
  • Fern Duvall
  • Nick Holmes
  • Darcy Hu
  • Seth Judge
  • Jay Penniman
  • Keith A. Swindle
Population ecology - Original Paper

DOI: 10.1007/s00442-011-2085-y

Cite this article as:
Wiley, A.E., Welch, A.J., Ostrom, P.H. et al. Oecologia (2012) 168: 119. doi:10.1007/s00442-011-2085-y

Abstract

Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (δ13C, δ15N and δD, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with ΦST = 0.50 (p < 0.0001). Coalescent-based analyses gave estimates of <1 migration event per 1,000 generations. Hatch-year birds from Kauai had significantly lower δ13C and δ15N values than those from Hawaii. This is consistent with Kauai birds provisioning chicks with prey derived from near or north of the Hawaiian Islands, and Hawaii birds provisioning young with prey from regions of the equatorial Pacific characterized by elevated δ15N values at the food web base. δ15N values of Kauai and Hawaii adults differed significantly, indicating additional foraging segregation during molt. Feather δD varied from −69 to 53‰. This variation cannot be related solely to an isotopically homogeneous ocean water source or evaporative water loss. Instead, we propose the involvement of salt gland excretion. Our data demonstrate the presence of foraging segregation between proximately nesting seabird populations, despite high species mobility. This ecological diversity may facilitate population coexistence, and its preservation should be a focus of conservation strategies.

Keywords

Gene flow Niche segregation Population ecology Salt load Stable isotopes 

Copyright information

© Springer-Verlag (outside the USA) 2011

Authors and Affiliations

  • Anne E. Wiley
    • 1
  • Andreanna J. Welch
    • 2
    • 3
  • Peggy H. Ostrom
    • 1
  • Helen F. James
    • 4
  • Craig A. Stricker
    • 5
  • Robert C. Fleischer
    • 2
  • Hasand Gandhi
    • 1
  • Josh Adams
    • 6
  • David G. Ainley
    • 7
  • Fern Duvall
    • 8
  • Nick Holmes
    • 9
  • Darcy Hu
    • 10
  • Seth Judge
    • 11
  • Jay Penniman
    • 12
  • Keith A. Swindle
    • 13
  1. 1.Department of ZoologyMichigan State UniversityEast LansingUSA
  2. 2.Smithsonian Conservation Biology InstituteCenter for Conservation and Evolutionary Genetics, National Zoological ParkWashingtonUSA
  3. 3.Behavior, Ecology, Evolution and Systematics ProgramUniversity of MarylandCollege ParkUSA
  4. 4.Department of Vertebrate Zoology, National Museum of Natural HistorySmithsonian InstitutionWashingtonUSA
  5. 5.U.S. Geological Survey, Fort Collins Science Center, Denver Federal CenterDenverUSA
  6. 6.U.S. Geological Survey, Western Ecological Research Center, Pacific Coastal & Marine Science CenterSanta CruzUSA
  7. 7.H.T. Harvey and AssociatesLos GatosUSA
  8. 8.Hawaii Department of Land and Natural Resources, Division of Forestry and Wildlife, Maui DistrictWailukuUSA
  9. 9.Kauai Endangered Seabird Recovery Project, University of Hawaii, Pacific Cooperative Studies UnitWaimeaUSA
  10. 10.National Park Service, Pacific West Regional OfficeHonoluluUSA
  11. 11.University of Hawaii, Pacific Cooperative Studies UnitHonoluluUSA
  12. 12.Maui Nui Seabird Recovery Project, University of Hawaii, Pacific Cooperative Studies UnitHaikuUSA
  13. 13.US Fish and Wildlife ServiceHonoluluUSA

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