Hooded Warbler
Ecoregional Scale Conservation Planning

Made possible through a partnership with the National Wetlands Research Center

Chuck-will's-widow (Caprimulgus carolinensis )
The chuck-will’s-widow is a Neotropical migrant that breeds in the southeastern United States. The species has experienced significant yet small declines in the WGCP over the last 40 years (1.3 percent per year; Sauer and others 2005). Numbers in the CH have remained relatively stable during this same period Table 005 (Table 005) . Chuck-will’s-widow is as Bird of Conservation Concern and a PIF species in need of management attention in the WGCP (regional combined score = 16). The species has no special conservation status in the CH (regional combined score = 14; Table 001 Table 001) .
Relative abundance of Chuck-will's-widow, derived from Breeding Bird Survey data, 1994 - 2003.
image courtesy of www.whatbird.com

Natural History:

The chuck-will’s-widow, like all nightjars, is nocturnal and most active on moonlit nights. Because of this and its cryptic coloration, chuck-will’s-widows are difficult to study, and few systematic investigations of their habitat, demography, or population status have been conducted. The majority of information on chuck-will’s-widows is anecdotal and coincident to investigations on other species (Straight and Cooper 2000).

Chuck-will’s-widows occur in woodland habitats interspersed by large openings in which birds forage at night. Calling males are equally abundant among suburban, pasture, and forested landscapes (Cooper 1981). Urban habitats are unsuitable (Straight and Cooper 2000). Chuck-will’s-widows prefer more open habitats than whip-poor-wills (Cooper 1981) and are unaffected by forest fragmentation (they may even benefit from it). Drier sites are preferred as well.

Model Description:

The first suitability function combines landform, landcover, and successional age class into a single matrix (SI1) that defines unique combinations of these classes Table 056 (Table 056) . We directly assigned suitability index scores to these combinations based on data from Hamel (1992) on the habitat associations of chuck-will’s-widows in the Southeast.

The realized suitability of the sites identified in SI1 depends largely on their landscape context. Cooper (1981) observed highest chuck-will’s-widow abundance in areas with equal amounts of forest and agriculture. Therefore, we used the proportion of these two habitats in a 500-m radius window (SI2) in our model of chuck-will’s-widow habitat suitability. We assigned the maximum suitability index score (1.000) to landscapes characterized by 50 percent forest and 50 percent agriculture. We reduced these scores as landscapes varied from this optimal configuration towards either a more open or forested composition with a stronger reduction in suitability for increasingly forested landscapes Table 057 (Table 057) .

The overall suitability index score for chuck-will’s-widow is based solely on SI2, which incorporates the results from SI1.

Overall SI = SI2