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.

Individual Differences, Parasites, and the Costs of Reproduction for Bighorn Ewes (Ovis canadensis)

Marco Festa-Bianchet
Journal of Animal Ecology
Vol. 58, No. 3 (Oct., 1989), pp. 785-795
DOI: 10.2307/5124
Stable URL: http://www.jstor.org/stable/5124
Page Count: 11
  • 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.
Individual Differences, Parasites, and the Costs of Reproduction for Bighorn Ewes (Ovis canadensis)
Preview not available

Abstract

(1) The consequences of reproduction for subsequent survival and reproductive success of individually marked bighorn ewes (Ovis canadensis) were examined over 8 years in south-western Alberta, Canada. (2) Ewes that raised sons did not experience a decrease in reproductive success the following year, but their faecal output of lungworm (Protostrongylus spp.) larvae increased relative to ewes that raised daughters. (3) Ewes were seldom known to produce sons in consecutive years. Because lamb sex was not determined at birth, this result could be explained by either an alteration of the birth sex ratio, or differential mortality of sons born in the year after their mother had produced a son. (4) Ewes that lactated at 2 years of age appeared to be in better condition, and were more likely to lactate at 3 years of age, than ewes that did not lactate at 2 years. Overall, reproductive success in one year did not aversely affect reproduction the following year. (5) Lactating ewes had greater faecal counts of lungworm larvae than non-lactating ewes. Ewes that had produced a lamb at 2 years of age were more likely to die during a pneumonia epizootic than ewes that had not lambed at 2 years. A decrease in resistance to parasites and pathogens appears to be a consequence of reproduction.

Page Thumbnails

  • Thumbnail: Page 
785
    785
  • Thumbnail: Page 
786
    786
  • Thumbnail: Page 
787
    787
  • Thumbnail: Page 
788
    788
  • Thumbnail: Page 
789
    789
  • Thumbnail: Page 
790
    790
  • Thumbnail: Page 
791
    791
  • Thumbnail: Page 
792
    792
  • Thumbnail: Page 
793
    793
  • Thumbnail: Page 
794
    794
  • Thumbnail: Page 
795
    795