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.

Sperm Competition: Mating System, Not Breeding Season, Affects Testes Size of Primates

A. H. Harcourt, A. Purvis and L. Liles
Functional Ecology
Vol. 9, No. 3 (Jun., 1995), pp. 468-476
DOI: 10.2307/2390011
Stable URL: http://www.jstor.org/stable/2390011
Page Count: 9
  • Read Online (Free)
  • Download ($18.00)
  • 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.
Sperm Competition: Mating System, Not Breeding Season, Affects Testes Size of Primates
Preview not available

Abstract

1. In taxa in which several males mate with a fertile female, males have larger testes relative to their body size than do males of taxa where only one male normally mates. However, breeding seasonality could confound the association: some species with breeding seasons have unusually large testes; seasonal breeding could concentrate fertile females in time, so making them difficult to defend and thus promoting multi-male groups. 2. Using data from 58 species of primates, and carefully accounting for phylogeny, we investigate the potential for breeding seasonality to confound the relation between testes size and mating system. 3. No confounding effect exists. Multi-male taxa have very significantly larger testes for their body size than do single-male taxa, independently of seasonality of breeding. Seasonality has no effect whatsoever in our sample, although few primates have very short breeding seasons. 4. While multi-male genera are equally likely to be seasonal as non-seasonal breeders, the single-male taxa of our sample are rarely seasonal, apparently supporting the difficulty of defence hypothesis but the sample by no means allows a firm conclusion.

Page Thumbnails

  • Thumbnail: Page 
468
    468
  • Thumbnail: Page 
469
    469
  • Thumbnail: Page 
470
    470
  • Thumbnail: Page 
471
    471
  • Thumbnail: Page 
472
    472
  • Thumbnail: Page 
473
    473
  • Thumbnail: Page 
474
    474
  • Thumbnail: Page 
475
    475
  • Thumbnail: Page 
476
    476