Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

The Measurement of Overall Body Size in Birds

James D. Rising and Keith M. Somers
The Auk
Vol. 106, No. 4 (Oct., 1989), pp. 666-674
Stable URL: http://www.jstor.org/stable/4087673
Page Count: 9
  • Read Online (Free)
  • Download ($12.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
The Measurement of Overall Body Size in Birds
Preview not available

Abstract

We compared a number of univariate and multivariate measures of body size used commonly in ornithological research, including eight multivariate measures (from principal components analyses), plus skull length, ulna length, tibiotarsus length, wing length, and weight. Analyses are based on 26 measurements on three randomly selected male and three randomly selected female Savannah Sparrows (Passerculus sandwichensis) from each of 53 different geographic localities throughout the species' range. Six of the eight principal components analyses provided essentially the same information about body size. Analyses based on the variance-covariance matrix of raw or log-transformed data provided first axes that varied most from the other multivariate estimates of size. Among the univariate measures, ulna length, wing length, and body weight contributed information that diverged from the multivariate measures of overall size. Weight better represents general size (i.e. PC I) than wing length, but because of variation in reproductive condition, weight is a far better measure in males than in females. Wing length is not a representative measure of body size. Inasmuch as each principal components analysis provides information about body size on PC I, we encourage researchers to choose among the various approaches according to analytical objectives rather than methodological simplicity or general utility.

Page Thumbnails

  • Thumbnail: Page 
666
    666
  • Thumbnail: Page 
667
    667
  • Thumbnail: Page 
668
    668
  • Thumbnail: Page 
669
    669
  • Thumbnail: Page 
670
    670
  • Thumbnail: Page 
671
    671
  • Thumbnail: Page 
672
    672
  • Thumbnail: Page 
673
    673
  • Thumbnail: Page 
674
    674