Microhabitat Factors Associated with Use of Habitat Edges and Woodlots by Northern Bobwhites during Winter in Southwest Ohio

Mark Wiley, MS Candidate
Advisor: Robert Gates

Many factors have contributed to the decline of northern bobwhite (Colinus virginianus) populations during the 20th century. The primary cause is habitat alteration at site and landscape levels. Ohio bobwhite populations declined 76% during 1984-2004. Concurrent with the decline, Ohio bobwhite range contracted and is now restricted to the southwestern portion of the state. Although landscape composition in the region is favorable to bobwhite, a patchy distribution of populations remains in the region. This distribution suggests that site-level characteristics are important to consider when evaluating bobwhite habitat quality. Ohio bobwhites have relatively high winter mortality, a characteristic of populations in the northern extent of their range. Survival during this period has been shown to differentially influence population growth rates. Availability and quality of habitat decrease during winter after leaf-fall and the senescence of herbaceous vegetation. This investigation aims to address uncertainties regarding availability of suitable winter habitat at the site level in southwestern Ohio. I will use radio telemetry data to identify and compare used and unused locations by bobwhite coveys during 1 December-28 February on 4 unique sites. I will quantify microhabitat characteristics of both used and unused points within 3 habitat strata. Results from this research will help to identify the characteristics of suitable winter habitat for northern bobwhites within a modern agricultural landscape and determine whether suitable habitat is limiting within these sites. These results will help to inform site level management decisions focused on improving winter habitat within landscapes still suitable for bobwhites in their northern range.