Extensive conversion of Midwestern riparian areas for agricultural production has had many consequences including reduced habitat for nesting birds. However, more than 120,000 ha of riparian habitat have been restored in this region through USDA conservation programs. In 2001 and 2002, we assessed songbird responses to burning and disking for management of conservation easements in east-central Iowa. We randomly assigned herbaceous riparian fields to burning and disking treatments and collected data on density and species richness of songbirds in these habitats. Total density of grassland and wetland species and red-winged blackbirds (Agelaius phoeniceus) were reduced by burning in the first and second breeding seasons after burning; common yellowthroat (Geothlypis trichas) density decreased with burning only in the first season. Disking led to increased density of grassland and wetland birds and greater overall avian conservation value on treated relative to untreated fields in the year after treatment. Changes associated with burning and disking treatments were likely related to changes in both vegetation structure and abundance of arthropod food resources. Despite decreased bird densities with burning, fire is a necessary management tool to control woody vegetation. Overall, both burning and disking appear to be effective management practices for maintaining herbaceous riparian habitats for grassland birds.
Available at: http://works.bepress.com/stephen_dinsmore/70/