Oecologia

, Volume 183, Issue 1, pp 291–301

Seasonal fecundity is not related to geographic position across a species’ global range despite a central peak in abundance

  • Katharine J. Ruskin
  • Matthew A. Etterson
  • Thomas P. Hodgman
  • Alyssa C. Borowske
  • Jonathan B. Cohen
  • Chris S. Elphick
  • Christopher R. Field
  • Rebecca A. Kern
  • Erin King
  • Alison R. Kocek
  • Adrienne I. Kovach
  • Kathleen M. O’Brien
  • Nancy Pau
  • W. Gregory Shriver
  • Jennifer Walsh
  • Brian J. Olsen
Global change ecology – original research

DOI: 10.1007/s00442-016-3745-8

Cite this article as:
Ruskin, K.J., Etterson, M.A., Hodgman, T.P. et al. Oecologia (2017) 183: 291. doi:10.1007/s00442-016-3745-8

Abstract

The range of a species is determined by the balance of its demographic rates across space. Population growth rates are widely hypothesized to be greatest at the geographic center of the species range, but indirect empirical support for this pattern using abundance as a proxy has been mixed, and demographic rates are rarely quantified on a large spatial scale. Therefore, the texture of how demographic rates of a species vary over its range remains an open question. We quantified seasonal fecundity of populations spanning the majority of the global range of a single species, the saltmarsh sparrow (Ammodramus caudacutus), which demonstrates a peak of abundance at the geographic center of its range. We used a novel, population projection method to estimate seasonal fecundity inclusive of seasonal and spatial variation in life history traits that contribute to seasonal fecundity. We replicated our study over 3 years, and compared seasonal fecundity to latitude and distance among plots. We observed large-scale patterns in some life history traits that contribute to seasonal fecundity, such as an increase in clutch size with latitude. However, we observed no relationship between latitude and seasonal fecundity. Instead, fecundity varied greatly among plots separated by as little as 1 km. Our results do not support the hypothesis that demographic rates are highest at the geographic and abundance center of a species range, but rather they suggest that local drivers strongly influence saltmarsh sparrow fecundity across their global range.

Keywords

Latitudinal gradients Fecundity Species range Biogeography Ammodramus caudacutus 

Supplementary material

442_2016_3745_MOESM1_ESM.docx (714 kb)
Supplementary material 1 (DOCX 713 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • Katharine J. Ruskin
    • 1
  • Matthew A. Etterson
    • 2
  • Thomas P. Hodgman
    • 3
  • Alyssa C. Borowske
    • 4
  • Jonathan B. Cohen
    • 5
  • Chris S. Elphick
    • 4
  • Christopher R. Field
    • 4
  • Rebecca A. Kern
    • 6
    • 7
  • Erin King
    • 8
  • Alison R. Kocek
    • 5
  • Adrienne I. Kovach
    • 9
  • Kathleen M. O’Brien
    • 10
  • Nancy Pau
    • 11
  • W. Gregory Shriver
    • 6
  • Jennifer Walsh
    • 9
  • Brian J. Olsen
    • 1
  1. 1.School of Biology and Ecology, Climate Change InstituteUniversity of MaineOronoUSA
  2. 2.Mid-Continent Ecology DivisionU. S. Environmental Protection AgencyDuluthUSA
  3. 3.Maine Department of Inland Fisheries and Wildlife, Bird GroupBangorUSA
  4. 4.Department of Ecology and Evolutionary Biology, Center for Conservation and BiodiversityUniversity of ConnecticutStorrsUSA
  5. 5.Department of Environmental and Forest BiologyState University of New York College of Environmental Science and ForestrySyracuseUSA
  6. 6.Department of Entomology and Wildlife EcologyUniversity of DelawareNewarkUSA
  7. 7.U. S. Fish and Wildlife ServiceEdwin B. Forsythe NWRGallowayUSA
  8. 8.U. S. Fish and Wildlife Service, Region 5 Division of Natural ResourcesStewart B. McKinney NWRWestbrookUSA
  9. 9.Department of Natural Resources and the EnvironmentUniversity of New HampshireDurhamUSA
  10. 10.U. S. Fish and Wildlife ServiceRachel Carson National Wildlife RefugeWellsUSA
  11. 11.U. S. Fish and Wildlife ServiceParker River National Wildlife RefugeNewburyportUSA

Personalised recommendations