Reclaimed surface mine site characteristics and nest box placement influence nest box use by American kestrels Falco sparverius in northern West Virginia and southern Pennsylvania, USA

American kestrels Falco sparverius will readily nest in suitably designed nest boxes but placement influences box uptake. In this study, how box placement and reclaimed surface mine characteristics influence box uptake was investigated in northern West Virginia and southern Pennsylvania.

In 1980, 60 nest boxes were erected at 18 mines, and in 1981, 91 were erected at 24 mines. During March to August 1980 and 1981, box use and nesting outcome was monitored. Natural nest cavities were mostly absent. To examine factors that might influence box use, the following were recorded: box location characteristics, vegetation characteristics of each mine, and insect and rodent abundance (i.e. potential kestrel prey items).

Kestrels used 14 of 60 (23%) boxes on 10 of 18 (56%) mines in 1980, and 33 of 91 (36%) boxes on 19 of 24 (79%) mines in 1981. During the 2-year study, 122 young fledged from the boxes. Nesting chronology, clutch sizes and numbers of young fledged were comparable to that reported in published studies of American kestrels on unmined areas.

The distance of a box to a woodland edge was the most important measured variable in predicting kestrel box use in both years. Only 10 of 65 (15%) woodland edge boxes were used compared with 47% of boxes located 50 m or more from a woodland edge. The author recommends therefore, that for best uptake, boxes should be erected on isolated trees that are at least 50 m from a woodland edge. Mines where kestrels used boxes had significantly lower bare ground cover and a deeper litter layer than unused mines.

Note: If using or referring to this thesis, please quote the original citation. A published Thesis abstract can be viewed in Journal of Raptor Research (spring 1983), 17, 30-31