Wildlife Use of Experimental Intercropping Systems

Project Overview

Project Type: Research and Education
Funds awarded in 1991: $0.00
Projected End Date: 12/31/1993
Matching Non-Federal Funds: $50,500.00
ACE Funds: $39,100.00
Region: North Central
State: Iowa
Project Coordinator:
Louis Best
Iowa State University

Annual Reports


  • Agronomic: corn, oats, soybeans
  • Animals: poultry


  • Animal Production: general animal production
  • Crop Production: intercropping, strip tillage
  • Natural Resources/Environment: wildlife
  • Production Systems: agroecosystems


    Agricultural cropland constitutes most of the habitat available to wildlife in the Midwest. Some of these habitats have proven to be "ecological traps" for birds where productivity is well below levels necessary to sustain populations. Strip intercropping systems may improve habitat conditions for wildlife in agroecosystems. We evaluated bird use of experimental strip intercropping systems in 1992 and 1993 by observing bird behavior from tower blinds, censusing along transects, and searching for nests. Small-mammals were evaluated by using Sherman live-traps. Thirty-five bird species were observed with brown-headed cowbirds and vesper sparrows most abundant. Foraging was the most common bird behavior observed, and soybean and corn strips were preferred for use by birds. Four species of birds nested in strip intercropping systems, although only vesper sparrows nested in 1992. Only 2.4% of vesper sparrow nests successfully fledged young. Remaining nests were destroyed by cultivation or planting activities (39.0%), predators (29.3%), brown-headed cowbird parasitism (12.0%), weather (4.9%), desertion (4.9%), or observer error (2.4%). Two nests had unknown outcomes. Six small-mammal species were captured, although 94.3 % of all animals captured were deer mice. Deer mice prefer oat strips before oat harvest and soybean or corn strips after oat harvest. Bird species diversity and abundance is high in strip intercropping systems suggesting better foraging habitat than conventional row crop fields. These systems, however, provide ecological traps for birds by attracting them to nest in a poor production area. Small-mammal diversity in strip intercropping systems is low, although greater structural diversity in these systems might provide attractive small-mammal habitat for a greater period of the growing season than in conventional row crop fields.

    Project objectives:

    1. Document bird and small-mammal abundance and species composition in an experimental strip intercropping system.

    2. Determine preferential use of various crop strips by birds and small-mammals.

    3. Assess avian nesting success and productivity in the strip intercropping system.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.