The Loggerhead Shrike ( Lanius ludovicianus) is a songbird with the habits of a raptor, a denizen of grasslands and other open habitats throughout much of North America. This masked black, white, and gray predator hunts from utility poles, fence posts and other conspicuous perches, preying on insects, birds, lizards, and small mammals. Lacking a raptor's talons, Loggerhead Shrikes skewer their kills on thorns or barbed wire or wedge them into tight places for easy eating. Their numbers have dropped sharply in the last half-century.
Identifying the Loggerhead Shrike
In the South, Loggerhead Shrikes are quite common and you can quite easily find them by scanning fence posts, power poles and lines, and other obvious perches in open country. The species has become quite rare in the Northeast and upper Midwest and finding it there is much more problematic. However, your best bets involve searching areas of rough grassland with scattered shrubs and trees for the bird or for their caches of prey. In the West, Loggerhead Shrikes can be fairly common in similar open habitats.
The loggerhead shrike is a songbird slightly smaller than a robin. Its striking appearance includes a broad black mask through the eyes, gray back and breast, a white spot on black wings, and white edges on a black tail. Despite its small robin-like stature, the habits of a shrike reflect those of a raptor.
Habitat and Distribution
Loggerhead Shrikes are found in grasslands, shrublands, grazed pastures and agricultural areas. In Indiana, shrikes are most frequently found on traditional farms with livestock pasture and smaller fields with a variety of crops bordered by shrubby hedgerows and fence lines.
Throughout most of the southern part of its range, the Loggerhead Shrike is resident; northern populations are migratory. Where resident, this species usually lives in pairs on permanent territories. The Loggerhead Shrike is the only one of the world's thirty species of true shrikes that occurs exclusively in North America. Like other shrikes, it inhabits ecotones, grasslands, and other open habitats and feeds on a variety of invertebrate and vertebrate prey.
Read also: What Loggerheads Eat
Nickname
Referred to as the “butcher bird” this species may be the most macabre and disturbing passerine of all - the loggerhead shrike.
Food Habits: The Diet of a "Butcher Bird"
Loggerhead shrikes have strong, hooked bills that allow them to take prey items large for their size. Even though they lack the strong talons of a raptor to hold down and manipulate prey, they compensate by anchoring their prey from thorns or barbed wire to tear prey into bite-sized pieces. Prey hung up in this way can also be conveniently stored for later. This behavior has earned them the nickname of “butcher bird.”
Loggerhead shrikes are predatory songbirds. Insects make up to 68% of their diet, but they also hunt small vertebrates including amphibians, reptiles, mammals and birds.
Shrikes have a diverse diet that includes beetles, grasshoppers, wasps, spiders, mice, voles, house sparrows, snakes and frogs. Diet in summer is mainly insects, especially grasshoppers and crickets, also beetles, wasps, and others. Eats mice and other rodents at all seasons, especially in winter, and eats small birds. Also sometimes included in diet are spiders, snails, frogs, lizards, snakes, crayfish, small fish, and other items.
Hunting Techniques: A Raptor in Songbird's Clothing
The shrike's hunting strategy is often compared to that of raptors like eagles, hawks, and falcons: They’ll sit on an elevated perch, scan the ground below, and pounce on any spotted prey. They often hunt from perches, scanning the ground from a utility wire, post, fence or plant stalk, and pouncing on prey spied below.
Read also: The Hoxsey Diet
Shrikes kill their vertebrate prey by attacking the nape of the neck. Like raptors, shrikes have a sharp triangular tomial tooth on their upper break, which they use to quickly sever the spinal cord of their prey. However, they don’t have heavy talons to hold their prey. They solve this problem by impaling their prey on thorns, barbed wire or sharp twigs. This unique habitat has earned them the nickname “butcher birds.”
Famous for impaling their victims, these songbirds first use a special maneuver to break the necks of small rodents. A new analysis of high-speed video footage finally reveals the answer: They grasp mice by the neck with their pointed beak, pinch the spinal cord to induce paralysis, and then vigorously shake their prey with enough force to break its neck.
As the new study reveals, once shrikes induce paralysis with a precise bite to the neck, they roll their heads rapidly to vigorously shake their immobilized food. According to the researchers, this back-and-forth whipping motion generates accelerations of up to six g-forces-roughly the same amount of force felt by passengers on high-g rollercoasters, or the whiplash experienced by victims of low-speed, rear-end car crashes.
The Larder: A Grisly Pantry
Unlike the falcon, however, shrike legs are just like those of any other songbird and are too weak to hold onto the carcasses of their kills as they rip the flesh away from the dead body. This is one of the reasons they need to spear their prey with sharp objects. The grisly scene they make is called a “larder.”
They impale the corpse of their prey on something thorny like a honey locust tree, or barbed wire fence when nature’s thorns are scarce. The shrike will then either eat it immediately or store it for later.
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As the term suggests, a shrike’s larder functions as food storage. During the breeding season, the male keeps the larder full nearby the nest so that the incubating/brooding female has a readily available cache of food. In the winter, storing prey in a larder may be an adaptation for periods when food is scarce. Caching may also function in mate attraction.
These larders could be robbed by other birds, especially corvids like blue jays and crows, given how easy it is to spot them, so keeping a big supply in the larder may compensate for some losses that are bound to occur.
It’s a behavior that seems to be deeply ingrained, as even non-food items get impaled. Most songbirds, for example, will dispose the fecal sacs (yes, their poop) of nestlings by dropping them somewhere away from the nest. Shrikes will impale the fecal sacs (I have photos if you’re curious).
Nesting Habits
Nests are substantial structures made of small twigs and grass, lined with horse hair or wool, and placed in a shrub or small tree. Eastern red cedars and rose bushes are favorite nesting sites in Indiana, especially when the bush is isolated within a fencerow. Shrikes will sometimes nest twice in one season, especially if the first nest fails.
In many regions, nesting begins quite early in spring. In courtship, male performs short flight displays; male feeds female. Nest: Placed in a dense (and often thorny) tree or shrub, usually 5-30' above the ground, occasionally higher, in a spot well hidden by foliage. Nest (built by both sexes) is a solidly constructed but bulky cup of twigs, grass, weeds, strips of bark, lined with softer materials such as rootlets, animal hair, feathers, plant down.
Incubation is by female, about 16-17 days. Male feeds female during incubation (sometimes bringing her food he has stored on thorns earlier). Both parents feed nestlings. Young leave nest at about 17-21 days, are tended by parents for another 3-4 weeks.
Conservation Status and Threats
Loggerhead shrikes have been undergoing alarming population declines in the eastern United States and are a state-endangered bird in Indiana and many other states. Reasons for this decline are puzzling and likely include a combination of factors:
- loss of quality breeding habitat
- use of pesticides
- collisions with vehicles
- increasing human development on wintering grounds in the southern United States
Loggerhead shrikes were included on Indiana’s state-endangered list when it was first developed in 1981, and they remain there today. In 1999-2000, the DNR Division of Fish & Wildlife (DFW) biologists did extensive surveying for shrikes and found them in 58 locations. In the years since these studies were done, shrikes have shown a dramatic decline. Since 2010, DFW biologists conducting annual surveys have found three to eight nesting territories each year in the entire state.
There is one endangered species of shrike called the San Clemente Island loggerhead shrike, and is found only on San Clemente island off the coast of California.
Management and Conservation Efforts
Landowners can help shrikes and other wildlife by preserving their fencerows and the shrubs that grow along them. Since shrikes typically build their nests in isolated bushes and trees along a fencerow, allowing several large isolated bushes is a great way to increase nesting habitat for this unique species. If fencerows need to be cleared, it is best to wait until after the nesting season to give baby birds a chance to survive. Nesting season occurs from early March to late August. Besides shrikes, many other native birds choose to build their nests in fencerows, and food and cover is provided for species like dove, rabbits, and bobwhite quail. Farms with healthy fencerows have a greater diversity of native wildlife than those without, and many of these native species are beneficial for insect and pest control.
Wildlife biologists within the DFW monitor the status, distribution, and relative abundance of the loggerhead shrike population through periodic surveys and color banding individual birds. These efforts might help explain some of the factors responsible for the decline.