CHANGES IN DISTRIBUTION AND ABUNDANCE OF THE LOGGERHEAD SHRIKE

The Loggerhead Shrike (Lanius ludovicianus) was once widely distribute d and common over most of North America, occupying an exclusive breedi ng range with no other shrikes. Although it occurs in a wide variety o f plant associations this shrike is generally found in landscapes char acterized by widely spaced shrubs and low trees interspersed with shor t grasses, forbs, and bare ground habitats which include deserts scrub lands, savannas and some agricultural settings. The Loggerhead Shrike seems to have been always most abundant in the southern and western p ortions of its range with high breeding densities from Florida across the gulf states to Texas and throughout the arid regions of the West. A northeastward expansion in range occurred in the late 1800s in assoc iation with deforestation and agriculture, A similar north central exp ansion occurred in the 1900s with agricultural development of the nort hern Great Plains and aspen parklands. Contraction and decrease in num bers have been noted in parts of its range since the 1940s, concurrent with the regrowth of forests, loss of pasturelands, and intensive row -crop agriculture. More recently, Christmas Bird Count data and Breedi ng Bird Survey data have revealed an overall downward trend across the continent at least since 1966, although numbers are stable or increas ing in some locations. Field studies generally implicate alterations i n habitat structure and loss of habitat as factors responsible for cha nges in bleeding distribution and over-all abundance. Nevertheless, co nsidering its entire distribution in North America and its historical expansions and contractions of range associated with habitat changes, the Loggerhead Shrike does not appear threatened with extinction as a species. We favor a hands-on approach to management of the critically endangered subspecies, L. l. mearnsi and L. l. migrans, however and re commend extensive preservation of the natural scrub desert, shrub-step pe, western oak savanna, and southern savanna vegetation types, which appear to be optimal, core habitats for this species, as well as foste ring land-use practices that favor shrikes es in agricultural and subu rban landscapes.