Several days ago Leonard and I had another first-time avian visitor on our property (Modoc County CA), one of several uncommon sightings this spring. We are in the summer range of loggerhead shrikes (Lanius ludovicianus), but until now our pastures have not proved attractive to this only endemic North American shrike.
On first glance the loggerhead shrike looks similar to its cousin, the northern shrike (Lanius excubitor). Both birds have medium grey upper parts, grey-white underparts, black wings with a white patch at the base of the primaries and a black tail edged in white. The black bills have a hook at the end. Although the northern shrike is larger and paler, those characteristics are not much help in the field to a novice such as me unless the two species are beside each other. The difference I rely upon to distinguish the northern from loggerhead shrike is their black mask – the mask of the loggerhead shrike extends across the forehead while that of the northern shrike does not.
Loggerhead shrikes can be found in open areas throughout in North and Central America as far as southern Canada, with northernmost birds migrating south after the breeding season. The northern shrike breeds in the taiga and tundra of North America and moves into southern Canada and northern United States for the winter. Generally where Leonard and I live, we think of northern shrikes as winter visitors and expect to see loggerhead shrikes in the summer.
The loggerhead shrike is classified as a passerine (perching songbirds) but in many ways resembles a carnivore – with broad wings and a long tail for speed and maneuverability and large jaws and a powerful hooked bill to break the neck of prey and carry it off in its mouth. Unlike most raptors the loggerhead shrike does not have strong talons, but rather its feet are weak and not of much use in catching and carrying prey. Loggerhead shrikes prefer large insects and also capture rodents, small birds, snakes and lizards.
Shrikes have a habit of impaling their prey on barbed wire fences, thorns or other sharp objects. For this reason loggerhead shrikes are often commonly called butcher birds or thorn birds. Why do they impale their prey? The answer is unknown but perhaps impaling holds the food to make it easier to tear apart and eat, it may be a way to “store” food for later consumption or perhaps it is a way of marking territory.
“Loggerhead” refers to the large size of this shrike’s head compared to its body size.