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.

Tradeoffs Involved in Site Selection and Foraging in a Wolf Spider: Effects of Substrate Structure and Predation Risk

Ann L. Rypstra, Jason M. Schmidt, Brant D. Reif, Jill DeVito and Matthew H. Persons
Oikos
Vol. 116, No. 5 (May, 2007), pp. 853-863
Published by: Wiley on behalf of Nordic Society Oikos
Stable URL: http://www.jstor.org/stable/40235128
Page Count: 11
  • Read Online (Free)
  • 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.
Tradeoffs Involved in Site Selection and Foraging in a Wolf Spider: Effects of Substrate Structure and Predation Risk
Preview not available

Abstract

Understanding how animals weigh habitat features, exposure to predators and access to resources is important to determining their life history and distribution across the landscape. For example, when predators accumulate in structurally complex habitats, they face an environment with different competitive interactions, foraging opportunities and predatory risks. The wolf spider Pardosa milvina inhabits the soil surface of highly disturbed habitats such as agricultural fields throughout eastern North America. Pardosa displays effective antipredator behavior in the presence of chemical cues produced by a larger coexisting wolf spider, Hogna helluo. We used those cues to simulate predation risk in laboratory and field experiments designed to test the effects of habitat substrate and predation risk on site selection and prey consumption of Pardosa. In general, Pardosa preferred more complex substrates over bare dirt but those preferences were eliminated or reversed when cues from Hogna were present. Feeding trials revealed that substrate alone had few effects on Pardosa prey consumption, which we measured by documenting the change in the abdomen width. Although the presence of Hogna cues reduced prey consumption overall in field feeding trials, the negative effect of predation risk on prey consumption was only observed in grass and bare dirt substrates in the laboratory. We also found that prey capture was negatively affected by habitat complexity for both spider species but that same complexity offered Pardosa protection from predation by Hogna. This study provides insight into how two predator species interact to balance site selection and feeding in order to avoid predation. Shifts in foraging and distributional patterns of predators can have profound implications for their role in the food web.

Page Thumbnails

  • Thumbnail: Page 
853
    853
  • Thumbnail: Page 
854
    854
  • Thumbnail: Page 
855
    855
  • Thumbnail: Page 
856
    856
  • Thumbnail: Page 
857
    857
  • Thumbnail: Page 
858
    858
  • Thumbnail: Page 
859
    859
  • Thumbnail: Page 
860
    860
  • Thumbnail: Page 
861
    861
  • Thumbnail: Page 
862
    862
  • Thumbnail: Page 
863
    863