Behavioral Ecology and Sociobiology

, Volume 64, Issue 10, pp 1711–1720

Impact of time since collection on avian eggshell color: a comparison of museum and fresh egg specimens

  • Phillip Cassey
  • Golo Maurer
  • Camille Duval
  • John G. Ewen
  • Mark E. Hauber
Methods

DOI: 10.1007/s00265-010-1027-8

Cite this article as:
Cassey, P., Maurer, G., Duval, C. et al. Behav Ecol Sociobiol (2010) 64: 1711. doi:10.1007/s00265-010-1027-8

Abstract

Studies of avian eggshell coloration have been a long-standing research focus in behavioral evolutionary ecology. Museum collections have provided a widely used resource because they allow efficient sampling across broad temporal, geographical, and taxonomic ranges, even for species that are rare and for which sampling in the wild is ethically or practically unwarranted. We used reflectance spectrophotometry across the avian visual spectrum to compare eggshell color of specimens of the song thrush (Turdus philomelos) in two museums (Natural History Museum, UK and Auckland Museum, New Zealand) with each other and with eggshells collected fresh in New Zealand. These data enabled us to test the effects of source and storage in different museums, as well as time since collection, across four metrics of eggshell coloration: blue-green and ultraviolet chroma, overall brightness, and the spectral coefficient of variation. Variation within an egg, within a clutch, and among clutches, was similar between the two museum datasets but different from those of fresh eggs. We found significant differences in all four metrics between the collections, and that fresh eggshells reflected stronger in the blue-green wavelength than in museum eggs. This difference is most likely due to different preservation techniques and storage histories. Furthermore, an effect of time since collection was only apparent in the blue-green chroma and was higher in more recent museum eggshell samples. Our results support the use of historic museum samples in intraspecific studies of shell coloration providing that efforts are made to compare specimens, which were collected during similar periods.

Keywords

BirdsEgg colorFadingReflectance spectrophotometryUltraviolet

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Phillip Cassey
    • 1
  • Golo Maurer
    • 1
  • Camille Duval
    • 1
  • John G. Ewen
    • 2
  • Mark E. Hauber
    • 3
  1. 1.Centre for Ornithology, School of BiosciencesBirmingham UniversityEdgbastonUK
  2. 2.Institute of ZoologyLondonUK
  3. 3.Department of PsychologyHunter College of the City University of New YorkNew YorkUSA