Nesting associations between Buteo hawks and passerines have been reported in the literature for over a century (Sharp 1902, Cameron 1913, Bowles and Decker 1934, Bent 1937, Griffing 1974, McGillivray 1978). Reports involving passerine nesting associations with Swainson’s Hawks (Buteo swainsoni) and Ferruginous Hawks (Buteo regalis) have been anecdotal, and to our knowledge the importance of these associations has not been investigated. In their classification of nest defenses Collias and Collias (1984) recognized birds that use “protective nesting associations with formidable species.” These formidable species may include large birds of prey, colonies of seabirds, or aggressive insects. Konrad and Gilmer (1982) discussed a potentially mutualistic relationship between Western Kingbirds (Tyrannus verticalis) and Swainson’s Hawks, in which kingbirds may benefit from the presence of hawks in the form of protection from predators and additional food from insects attracted to the nest site by the presence of prey remains, dead hawk nestlings, or excrement. The raptors, in turn, may benefit from kingbirds feeding on pest insects and from their vigilance in alarm-calling and early detection of predators. We investigated nest-site selection of Western Kingbirds in sagebrush steppe of Oregon and provide support for the idea that this species prefers to nest in association with Swainson’s and Ferruginous Hawks.