The vast expanse of North American prairie has been reduced by at least 90% of its original area. As a result, the populations of many grassland birds are in serious decline. This study investigated Loggerhead Shrike (Lanius ludovicianus) population trends in Kansas by comparing two Breeding Bird Survey (BBS) routes (16 and 17) in north-central Kansas showing more stable shrike populations, with two BBS routes (06 and 07) in southern Kansas showing more dramatic declines during the last 30 years. With the exception of large increases in pesticide use, there have been few land-use changes the last 30 years along the two northern routes. Along the southern routes, land-use changes include large decreases in pasture, urbanization, loss of tree rows, and large increases in pesticide use.

Our land-use survey showed more pasture, woodland, scattered trees and shrubs, and barbed-wire fences in the north, and more wheat, residential areas, and tree rows in the south, indicating significant differences between study areas in key habitat requirements for breeding Loggerhead Shrikes. Our two-year census of the four BBS routes showed a higher density of shrikes in the north (3.0/census) than the south (1.9/census). The habitat associated with shrikes in the north showed a greater amount of pasture and significantly more scattered trees and shrubs compared to the south, where shrike habitats were more heterogeneous and usually associated with tree rows. The nesting success in both areas was relatively low for Loggerhead Shrikes.