Vaux’s Swift (Chaetura vauxi) is a migrant breeding from the western U.S. to northern Venezuela, wintering from central Mexico to Venezuela (AOU 1983). In 1994, the California Department of Fish and Game designated it as a “species of special concern.” Its breeding biology and habitat requirements are poorly known but are thought to be linked to old-growth forests (Lundquist and Mariani 1991; Bull and Hohmann 1993).
Fragmentation of old-growth forests and its effects on bird distribution in the western U.S. is a major issue (Harris 1984; Thomas et al. 1990). Most research on this topic focuses on the ecology of the Spotted Owl (Strix occidentalis), Marbled Murrelet (Brachyramphus marmoratus), and Pileated Woodpecker (Dryocopus pileatus), while other species like the Vaux’s Swift receive relatively little attention (Carey 1989; Ralph et al. 1991; Huff and Raley 1991).