American Kestrels (Falco sparverius) are widely distributed throughout North America. In Kentucky, these falcons are permanent residents and are most abundant in rural farmland where they hunt over fields and pastures (Palmer-Ball 1996). Although primarily sit-and-wait predators, hunting from elevated perches and scanning the surrounding areas for prey, kestrels also hunt while hovering (Balgooyen 1976). Kellner (1985) reported that nearly 20% of all attacks observed in central Kentucky were made while kestrels were hovering. Habitats used by hunting kestrels in central Kentucky include mowed and unmowed fields, cropland, pastures, and plowed fields (Kellner 1985).
Several investigators have suggested that male and female American Kestrels may exhibit differences in habitat use during the non-breeding period, with males typically found in areas with greater numbers of trees, such as wooded pastures, and females in open fields and pastures (Stinson et al. 1981, Bohall-Wood and Collopy 1986). However, Smallwood (1988) suggested that, when available, male and female kestrels in southcentral Florida established winter territories in the same type of habitat. Differential habitat use occurred only because migratory female kestrels usually arrived on wintering areas before males and, therefore, were more likely to establish territories in the better quality, more open habitats before males arrived (Smallwood 1988).
In central Kentucky, many American Kestrels are residents. As a result, male and female kestrels would likely have equal opportunity to establish winter territories in the higher quality, open habitats. If so, habitat segregation should be less apparent in central Kentucky than in areas further south where wintering populations of kestrels are largely migratory. In addition, territory quality should be correlated with individual quality because higher quality resident kestrels should be able to defend higher quality territories.
The objectives of my proposed study of American Kestrels will be to examine possible relationships among and between hunting behavior, territory quality, and individual quality in male and female American Kestrels. The results of this study will provide important information about habitat and perch selection by American Kestrels in central Kentucky in addition to the possible role of individual quality on hunting behavior and habitat use.