Habitat

Breeding Habitat

Typical Loggerhead Shrike habitat at the northern edge of the breeding range in Ontario, Canada

Typical Loggerhead Shrike habitat at the northern edge of the breeding range in Ontario, Canada

Barbed wire fencing creates many potential impaling sites that can be used by shrikes, like  the fledglings pictured here

Barbed wire fencing creates many potential impaling sites that can be used by shrikes, like  the fledglings pictured here

During the breeding season, shrikes use a variety of shrub and grassland habitats that vary from shrub-steppe in the western United States to pasturelands in northeast Canada. Despite apparent differences in habitat, all areas include open grassy foraging areas with scattered hunting perches and small trees or shrubs that are used as nest sites. 

Specific habitats for Loggerhead Shrikes have changed over time. Many shrikes now occupy “artificial” habitat that has been created or extensively altered by human activities. The fact that they have been able to adapt to these changes, combined with the varying habitat conditions across the broad range of the species, makes characterizing “typical” habitat difficult.

It can include:

  • pastures
  • old fields and orchards
  • mowed roadsides
  • cemeteries, suburban parks and golf courses
  • short and tall grass prairies and savannas
  • sagebrush and shrub-steppe, desert scrub and pinyon-juniper woodlands

All habitats include four common features:

  1. nesting sites - usually in thorny or prickly trees and shrubs that vary from region to region
  2. perches for hunting, singing, and calling
  3. foraging areas, usually with short or sparse grass
  4. impaling sites, which can include thorny shrubs, barbed wire fences or sharp twigs

 

Wintering Habitat

Relatively little is known about habitat use and population dynamics among migrating shrikes in the non-breeding season because there is no way to visually distinguish them from non-migrating shrikes. Recently, however, researchers have begun to use markers such as stable isotopes and specific genetic sequences to understand where migrant shrikes go in the winter, the habitat that they use and how they interact with non-migratory shrikes that reside in the area year-round. The limited work to date suggests that the wintering and breeding habitat of migrating shrikes are similar, but that migrating shrikes are using slightly different types of habitat than non-migrating shrikes.

Loggerhead shrike population declines have been the most drastic in areas that support migratory shrikes. This suggests that the declines are linked to threats faced during migration or on the wintering grounds — particularly habitat loss and degradation. If these areas have experienced habitat loss and degradation, migratory shrikes are forced to compete with residents for good habitat — and because the migratory birds aren’t there year-round, they likely get pushed to lower-quality habitat.