Dickcissel Photo courtesy of Missouri Department of Conservation.

Efforts are underway to improve Northern Bobwhite habitat within the Central Hardwoods Bird Conservation Region (CHBCR). Management actions taken for Bobwhite conservation, which include encouraging an interspersion of grassland for nesting and shrubland for cover, are also likely to affect other priority bird species that occupy similar habitats. For example, managing for large meadows of native grasses would provide nesting habitat for Henslow’s Sparrows, a grassland bird, but would exclude Prairie Warblers, a shrubland bird. However, having both habitat types in a local landscape would allow both species to persist.

During the spring and summer of 2008, scientists associated with the University of Tennessee began work to quantify how different management options for Bobwhite conservation will affect other priority bird species that occupy grassland or grass-shrubland habitats, and to assess the current population levels of and habitat usage by these species in the CHBCR. Part of this assessment involves fieldwork to assess the status of grass-shrubland bird populations and their habitat usage in the areas where Bobwhite conservation will be focused. A monitoring protocol was developed for this project that can be used by state agencies and others to provide valid estimates of population sizes, taking into account detection distances. The work was funded through a grant from Region 3 of the U. S. Fish and Wildlife Service.

The focus areas selected for Bobwhite conservation work were used to select counties for this assessment. Counties were used as sampling units because U.S. Department of Agriculture statistics are available at the county level, because Natural Resources Conservation Service and state private lands biologists use counties as management units, and because they are an adequate size for monitoring purposes.

In Summer 2008, bird surveys were conducted in the 25 counties outlined in red in the map. The map background shows the existing land cover types, as defined in the legend below.

Research scientists at the University of Tennessee conducted an analysis of how many acres of different types of grassland and grass-shrubland habitat are required to meet Partners in Flight population goals for the priority bird species associated with these habitat types on the CHBCR, and how those acreages compare with the goals of the Northern Bobwhite Conservation Initiative.

To assess the existing population sizes of grassland and grass-shrubland bird species, a monitoring project was designed; while it was patterned after the Breeding Bird Survey, the sampling protocol was modified to include methods appropriate for estimating densities of birds rather than simply providing an index to abundance. The CHJV provided assistance with spatial sampling, using GIS to select randomly distributed routes in the target counties and providing maps for the field crews. The routes were on secondary roads, outside of urban areas and were limited to "open habitats" (areas with less than 50 percent tree cover). In Summer 2008, field crews conducted bird surveys, stopping every half mile along 121 25-mile routes in twenty-five counties in Tennessee, Kentucky, Indiana and Illinois. Over 7000 individual birds were recorded. A second field season in Summer 2009 will add sites in Missouri and Arkansas.

Eight species were targeted: Bachman's Sparrow, Henslow's Sparrow, Field Sparrow, Dickcissel, Blue-winged Warbler, Prairie Warbler, Loggerhead Shrike and Northern Bobwhite. The occurrence of other species was also noted.

An ongoing project will map the potential historical distribution of grassland and grass-shrubland habitat across the CHBCR. This information will help guide work on natural community restoration, so that it can be targeted to areas that are best suited to support those community types.