Eastern Loggerhead Shrike (Lanius ludovicianus ssp.)
Since 2003, Wildlife Preservation Canada has been leading the recovery effort for this critically endangered songbird. A 2015 survey estimated that roughly a dozen wild breeding pairs remain, found in a few isolated spots in Ontario.
Named for its disproportionately large — or “logger” — head, the loggerhead shrike is a medium-sized songbird, slightly smaller than a robin. Like its larger cousin, the northern shrike, loggerhead shrikes use their hooked bills to dispatch mice, frogs, grasshoppers, beetles and other small prey — making these two species the only truly predatory songbirds. Because they lack strong talons for grasping their meals, shrikes impale their dead prey on the thorns of shrubs or barbed wire and then tear off manageable chunks with their beak.
There are twelve distinct subspecies of loggerhead shrike across North America, all virtually identical in appearance. Two of them, including the eastern loggerhead shrike, occur in Canada. The Canadian populations are migratory, although many U.S. populations are not. Where Canada’s eastern loggerhead shrikes spend their winters still remains largely a mystery.
Shrikes prefer flat, open areas of short grassland with scattered trees and shrubs that offer nesting sites and hunting perches. Shrikes can often be found in alvars: unique habitats consisting of shallow soils over limestone bedrock, resulting in naturally short grasslands. Elsewhere, cattle ranching and pastures help to keep the grass short for foraging.
Originally the range of the eastern loggerhead shrike extended from Manitoba to New Brunswick and as far south as northeastern Texas, western North Carolina and Maryland. Today, Canada’s eastern loggerhead shrike populations are restricted to several small isolated pockets in Ontario. This includes the Carden and Napanee limestone plains, where breeding pairs are consistently located. Individuals or breeding pairs are occasionally spotted on the Smiths Falls plain, in the Pembroke and Renfrew areas, in Grey and Bruce Counties on the Bruce Peninsula, and on Manitoulin Island. There is evidence that at least some individuals winter in the southeastern United States, migrating to Ontario in April for the breeding season.
The causes of the persistent decline in eastern loggerhead shrike populations are poorly understood. Historically, the greatest threat has been the loss and fragmentation of the short grassland they depend on. This is due to natural succession and changes in agricultural land use, particularly the conversion of pastures and hayfields to grow crops, which involves removing the hedgerows, shrubs and trees that are essential to the shrike’s lifestyle. Another potentially serious problem is motor vehicles. Shrikes often perch on fences and utility lines near roadways and sometimes collide with passing cars and trucks. The use of pesticides may also be a factor. However, the biggest factor driving shrike declines today seems to lie either on their migration routes or their overwintering grounds, reducing the number of birds that return to breed in Ontario each spring. On wintering grounds, migratory birds likely face the added pressure of competing with non-migratory resident loggerhead shrikes for resources.
Recommended Recovery Actions
The federal Recovery Strategy for eastern loggerhead shrike calls for a number of conservation measures, including habitat stewardship, conservation breeding and release, and research into the shrike’s migration routes and overwintering grounds.
What we are doing
Find out how Wildlife Preservation Canada helps save eastern loggerhead shrike and other Canadian birds, and how you can make a difference.