Southeastern American Kestrels Respond to an Increase in the Availability of Nest Cavities in North-Central Florida

Abstract

Abstract We conducted a nest-box study from 1989–93 in north-central Florida, in an effort to increase the population of the threatened Southeastern American Kestrel (Falco sparverius paulus) and to evaluate the effect of providing artificial nest sites on the local population. A total of 388 nest boxes were erected in the experimental area. Over 75% of these nest boxes were placed >250 m away from roadside transects we established. This enabled us to measure changes in population density without the potential bias associated with the concentration of kestrels at specific nest-box sites. Annual censuses were conducted along 20 16-km transects to quantify population density in the control (no nest boxes) and treatment zones. Breeding attempts in nest boxes increased during each year of the study. Kestrel densities along the experimental transects increased from 5.0 birds/100 km2 to levels equivalent to the control zone within 3 yr of nest box placement (32.3 vs. 34.9 birds/100 km2). Kestrels preferred nest...