Components of phenotypic variation in the morphometrics of shearwater (Puffinus) species

  • Bull L
  • Haywood J
  • Pledger S
  • 37


    Mendeley users who have this article in their library.
  • 12


    Citations of this article.


Coefficients of variation were used to examine the variability of bill, wing and foot measurements of 11 sexually size dimorphic and seven monomorphic shearwater ( Puffinus ) species, and to investigate the selective regimes that may be acting on these traits. The effects of phylogeny can lead to a lack of statistical independence among interspecies data, so randomization tests were performed in addition to standard statistical approaches, which assume independence. However, the results obtained from the two approaches always agreed. Among the 18 species, bill measurements were significantly more variable than those of the wing or foot; furthermore, bill depth dimensions exhibited the greatest amount of phenotypic variation. Both sexually monomorphic and sexually dimorphic species exhibited the same patterns of phenotypic variation. In the sexually dimorphic species, patterns of trait variation did not differ significantly between sexes. The findings suggest that variation in the bill of dimorphic Puffinus species is not due to sexual selection. More probably, variability among the traits is due to differences in the strength of natural selection, with those traits under strong stabilizing selection (e.g. wing, tarsus and mid-toe) exhibiting reduced variability, as optimum physical dimensions are being selected for.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • Leigh S. Bull

  • John Haywood

  • Shirley Pledger

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free