Montana Field Guide

Slightly smaller than American robin (Turdus migratorius); total length averages 23 cm. Stout, hooked, all-dark bill; bluish-gray head and back; white or grayish-white underparts, very faintly barred in adults; broad black mask extending above eye and thinly across top of bill; gray to whitish rump; black tail with white tip; large white patches in the black wings; juveniles are paler and barred overall, with brownish-gray upperparts and buffy wing patches; males and females are similar in appearance (Miller 1931, NGS 1983, Fraser and Luukkonen 1986). Most nests are made of coarse twigs with a lining of plant material and animal hair (Fraser and Luukkonen 1986).

Loggerhead Shrikes differ from Northern Shrikes (Lanius excubitor) by having the base of the lower mandible black instead of pale, unbarred or barely barred underparts (adults), a shorter and less hooked bill, a darker head and back, and a more extensive black mask. They differ from the Northern Mockingbird (Mimus polyglottos) by having a black mask and a shorter, less curved bill.

In the Bozeman area, normal migration periods are April 20 to May 15 and August 10 to September 10.

In Idaho, nests are found in sagebrush (65%), bitterbush, and greasewood, and are equally successful in all three (Woods and Cade 1996).

Loggerhead Shrikes nest from mid-June to mid-July (Davis 1961).