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.

Nest Predation and Its Relationship to Habitat and Nest Density in Dickcissels

John L. Zimmerman
The Condor
Vol. 86, No. 1 (Feb., 1984), pp. 68-72
DOI: 10.2307/1367348
Stable URL: http://www.jstor.org/stable/1367348
Page Count: 5
  • 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.
Nest Predation and Its Relationship to Habitat and Nest Density in Dickcissels
Preview not available

Abstract

Analysis of the histories of over 500 Dickcissel (Spiza americana) nests found in eastern Kansas showed that those in old-field habitats suffered more predation than those in prairies. Predation rates on the prairie, were not correlated with the weeks of the nesting season, but those in old-fields varied significantly with time. Although both predation rates and nest densities increased concurrently to a peak during the middle of the nesting season in old-fields, an analysis of the relationship between nest densities per week and both daily predation rates and the percent of nests lost to predators each week indicated that predation was not density-dependent. Predation rates are higher in old-fields than in prairies, not because of greater nest densities, but perhaps because predators are more abundant in old-fields. Snakes are the most probable nest predator, and their method of hunting, by chance encounters rather than by directed search, is suited to the absence of a density-dependent effect of predation on Dickcissel nests.

Page Thumbnails

  • Thumbnail: Page 
68
    68
  • Thumbnail: Page 
69
    69
  • Thumbnail: Page 
70
    70
  • Thumbnail: Page 
71
    71
  • Thumbnail: Page 
72
    72