Associated Species: Other species that may use habitat in a similar way and/or respond similarly to threats, management, and conservation activities include Ash-throated Flycatcher, Gray Flycatcher, and Gray Vireo.

Distribution: Cassin's Kingbirds breed in the Great Plains from southeastern Montana southward, and in the Southwest from central California, southern Utah and Colorado, southward to southern Mexico. They are uncommon to fairly common summer residents locally in southeastern Colorado, and rare to uncommon in western Colorado.

Habitat Requirements: Cassin's Kingbirds choose pinyon-juniper woodlands more often than other types. Sagebrush and rimrock are common habitat features. The percentage of sagebrush park area may exceed that of juniper or pinyon-juniper cover. In southeastern Colorado, cholla (candlestick) cactus is a component of their territory. While they nest in deciduous riparian and agriculture areas, Western Kingbirds exclude them from extensive use of these habitats.

Ecology: In comparison with Western Kingbirds, Cassin's prefer denser vegetation. They prefer pinyon-juniper habitat, and they appear to be less attracted to man-made structures. Both are migrants, but Cassin's Kingbirds usually stay longer and most individuals winter north of the Neotropics (Andrews and Righter 1992). Cassin's Kingbirds arrive in Colorado in mid to late April. Apparently they begin nesting activities later than Western Kingbirds and this may put them at a competitive disadvantage to their cogener. The incubation and nestling period is 26 to 28 days. Their nests are usually on horizontal limbs in the upper third of trees (Kingery 1998). The pugnacious nature of these birds may compensate for the ease with which predators and parasitic cowbirds can find their nests. Their sensitivity to human activity seems to be low.

Management Issues and Conservation Recommendations: Research is needed before many specific recommendations for this species can be offered. As with all kingbirds, promoting good nectar plant species would appear to be a significant practice to benefit this species.

Status and Reasons for Concern: This species has a high conservation need locally and throughout its range. The Colorado Plateau has the highest area responsibility for Cassin's Kingbirds, with more than 40% of their range falling within the physiographic area, and the species has a high overall priority ranking. The BBS results for 1969-1996 in Physiographic Area 87 do not indicate a statistically significant annual rate of change (P = 0.83, n = 45 routes). Cassin's Kingbirds were present on an average of 2.83% (SE = 1.49) of BBS routes run in Physiographic Area 87 in Colorado during 1988-1997, at an average abundance of 0.14 (SE = 0.09) individuals per route. This species is monitored by MCB with tracking transects.

Biological Objective: Maintain the presence of this species in every county in which nesting has been documented. In monitoring terms, it is to maintain the same number or more of pinyon-juniper woodland MCB point count transects on which this species occurs.

Selected References: Andrews and Righter 1992, Kingery 1998.