Cliff-nesting raptor survey of the Sioux District, Custer National Forest : 1994

Abstract

Field surveys of potential cliff nesting-sites for diurnal raptors were conducted in June and early July 1994 in the Chalk Buttes, the Ekalaka Hills and the southern half of the Long Pines of the Sioux District, Custer National Forest, Montana. All surveys were conducted on foot. About 300 separate sites were surveyed, falling into roughly 42 concentrations of cliffs and/or outcrops. Only three active Prairie Falcon nest sites and one probable Merlin nest site were identified. Because of time limitations of the 1994 field survey, it is anticipated that a comprehensive survey of greater duration of both the Montana and South Dakota portions of the Sioux District will identify additional nests not discovered in this preliminary effort. Nevertheless, the few nesting pairs detected are cause for concern, especially when contrasted with historical nesting data, and indicate the need for a more thorough field effort. Published literature and unpublished nest records indicate that significant numbers of Prairie Falcons, Merlins, and Golden Eagles have nested on and near Custer National Forest lands in recent decades. Ferruginous and Swainson's Hawks nest mostly off of the Custer National Forest. The Northern Goshawk is also a potential breeding species in low densities in mature pine stands, and future raptor inventory efforts should include surveys of its potential nesting habitat; one adult was seen in the Long Pines in June during the survey.