Associated Species: Other species that may use habitat in a similar way and/or respond similarly to threats, management, and conservation activities include Long-eared Owl and Northern Mockingbird.

Distribution: Loggerhead Shrikes breed from central Washington, the prairie provinces of Canada, and the northeastern United States to southern Mexico. In Colorado, they frequent the eastern plains, the San Luis Valley, and the desert lowlands of the Western Slope.

Habitat requirements: Loggerhead Shrikes require shrubby habitats in open country. On the eastern plains these are usually shelterbelts, abandoned farmsteads, and other small copses. In Physiographic Area 87, they seek tall desert shrubs, especially greasewood, saltbush, and sagebrush. They will also use pinyon-juniper at the edge of open desert country. Shrikes require thorny shrubbery (or barbed wire) upon which they impale their prey.

Ecology: Loggerhead Shrikes are relatively early nesters, arriving on territories in April, incubating and feeding nestlings in May, and fledging young in June. Their bulky nests, built of small twigs and bark strips, are placed in tall shrubs or small trees in open country. Large insects, especially grasshoppers, provide the bulk of their diet during the breeding season, but Loggerhead Shrikes are effective predators and also capture small birds, mice, and lizards.

Management Issues and Conservation Recommendations: Greasewood and robust sagebrush stands compete for preferred livestock forage and thus are targeted for vegetation conversion projects. Discourage conversions of this habitat. (Conversions in greasewood generally do not have a positive cost/benefit ratio. Conversions of other semidesert shrub types for livestock forage are not economical.)

Wildfires are the most significant threat to Loggerhead Shrikes in their semidesert shrubland habitat. Fully suppress wildfires in this habitat. Planting "greenstrips" to stop shrub-killing wildfires has shown promise in southern Idaho and may work as well in Colorado (BLM records).

High cattle traffic poses a direct physical threat to nests. Livestock tend to congregate where greasewood has the potential to support the most birds, on flat floodplains. Urge dispersal of grazing pressure in pastures with tall, dense shrub stands.

In rare years semidesert shrubland experiences a grasshopper or Mormon cricket population explosion. These events inspire insecticide spray programs that need careful planning to prevent the collapse of whole animal communities. Using insecticides across a broad area of non-agricultural semidesert shrubland is not appropriate on public lands and not economically viable on private rangelands, although it may be briefly politically attractive.

Status and Reasons for Concern: This species has a moderately high conservation need throughout its range, a high representation in the physiographic area, and a declining population trend. The Loggerhead Shrike is a species of moderately high global vulnerability. Between 1988 and 1997 Loggerhead Shrikes were detected on an average of 9.52% of the BBS transects run in Physiographic Area 87 (SE = 3.34). The BBS results for 1969-1996 for Physiographic Area 87 indicate an 8.9% annual rate of decline (P < 0.01, n = 44 routes). Continental BBS trends suggest a decline of 3.5% per year, with 63% of the routes reporting drops. This rate of decline will lead to the loss of two-thirds of the population in three decades (Kingery 1998). Loss of tall desert shrub habitat to development, disturbance of this habitat by grazing (especially in desert riparian areas), and heavy use of insecticides to combat grasshopper damage all pose threats to Loggerhead Shrike survival. This species is monitored by MCB with point transects.

Biological Objective: Maintain or increase the species' distribution and abundance, based upon results of the BBS and MCB monitoring programs. Maintain an average of one pair per 15 hectares (one pair per 37 ac) of >1 m (3 ft) tall desert shrub habitat [area equals about a 1.6 km (1 mi) continuous count belt transect 100 m (330 ft) wide]. Maintain nesting success averages greater than or equal to 2.5 on the Western Slope.

Selected References: Andrews and Righter 1992, Kingery 1998, Yosef 1996.