- 7.9–9.1 in
- 11–12.6 in
- 1.2–1.8 oz
- Smaller and more slender than an American Robin; larger and longer-tailed than a Western Bluebird.
- Pie-grièche migratrice (French)
- Alcaudon yanqui, Verdugo Americano (Spanish)
- A Loggerhead Shrike can kill and carry an animal as massive as itself. It transports large prey in its feet and smaller victims in its beak.
- The upper cutting edge (tomium) of the Loggerhead Shrike’s hooked bill features a pair of built-in pointy projections, aptly named “tomial teeth.” Like a falcon, the shrike tackles vertebrate prey with a precise attack to the nape, probably using these tomial “teeth” to paralyze the animal with a jab to the spinal cord.
- Loggerhead Shrikes impale noxious prey such as monarch butterflies and eastern narrow-mouthed toads—then wait for up to three days to eat them, which allows time for the poisons to break down. These shrikes also eat the heads and abdomens of toxic lubber grasshoppers, while discarding the insect’s poisonous thorax.
- Newly fledged Loggerhead Shrikes perform exaggerated, misdirected versions of adult hunting behavior. They peck at inanimate objects, fly about with leaves or sticks in their beaks, practice aerial chases without a target, or chase after their parents. They also perform rudimentary impaling gestures, grasping objects in the tip of their bill and repeatedly touching them to a branch or perch as if trying to get them to stick.
- Loggerhead Shrikes sometimes go hunting on cold mornings, when insect prey are immobilized by low temperatures.
- “Loggerhead,” a synonym for “blockhead,” refers to the unusually large size of this bird’s head in relation to its body.
- The longest-lived Loggerhead Shrike on record—a male—was at least 11 years, 9 months old when it was caught and released in 2010 by researchers in California.
Loggerhead Shrikes inhabit open country with short vegetation and well-spaced shrubs or low trees, particularly those with spines or thorns. They frequent agricultural fields, pastures, old orchards, riparian areas, desert scrublands, savannas, prairies, golf courses, and cemeteries. Loggerhead Shrikes are often seen along mowed roadsides with access to fence lines and utility poles.
Loggerhead Shrikes eat insects and other arthropods, amphibians, reptiles, small mammals, and birds; they also sometimes feed on roadkill and carrion. Their staple foods include agricultural pests such as grasshoppers, beetles and rodents. Insects generally dominate the Loggerhead Shrike’s diet during breeding season, while winter brings a greater reliance on vertebrate prey. These include lizards, snakes, frogs, turtles, sparrows, goldfinches, ground squirrels, voles, mice, and shrews, to name just a few.
- Clutch Size
- 5–6 eggs
- Number of Broods
- 1-2 broods
- Egg Length
- 0.9–1.1 in
- Egg Width
- 0.7–0.8 in
- Incubation Period
- 15–17 days
- Nestling Period
- 16–20 days
- Egg Description
- Eggs are grayish buff, marked with gray to yellowish-brown.
- Condition at Hatching
- Naked, blind, and helpless, with closed eyes.
Both sexes gather material. The female usually constructs the nest on her own, over a period of about 6–11 days. The bulky, well-insulated open cup is neatly woven of rootlets, twigs, forbs, and bark strips and lined inside with soft material such as flowers, lichen, grass, moss, feathers, fur, string, or cloth. The nest is about 6 inches in diameter on the outside, with an interior diameter of about 4 inches; the cup is about 3 inches deep.
Both sexes help find the nest site, inspecting many locations before choosing. Loggerhead Shrikes often build their nests in thorny vegetation, which may help keep predators away. In the absence of trees or shrubs, they sometimes nest in brush piles or tumbleweeds. Average height of nests above the ground ranges from about 2.5–4 feet.
Loggerhead Shrikes hunt by scanning the ground from elevated perches, then diving onto prey. They also hover-hunt. Loggerhead Shrikes sometimes hunt from the ground, flashing their wing patches in a manner similar to the Northern Mockingbird, to startle prey out of hiding. To immobilize large prey items, the Loggerhead Shrike impales them on sharp objects such as thorns and barbed wire, or tucks them into forks between branches. Caches of prey thus lain away, also called “larders” or “pantries,” provide food stores during winter when prey is scarce, or in breeding season when energy demands are high. A well-provisioned larder may also help a male shrike attract a mate. Loggerhead Shrikes maintain territories largely through songs and displays. Males challenge intruders with a wing-fluttering bow, like an intensified version of their prey-stalking display. Displaying rivals usually face away from one another, but may whirl to face each other or stamp the ground. Before nesting, several neighboring shrikes may gather together and call or display for several minutes. This may help establish territories in the neighborhood, promote pair formation, and help new arrivals find territories near already-established birds. Courting males feed and sing to females, perform a ritual dance, and/or perform a flight display. They are mostly monogamous, although females occasionally raise one brood with one male and then take up with another mate for a second brood the same season.
Loggerhead Shrikes are still fairly numerous in some areas (particularly the South and West), but their populations have fallen sharply over the past half-century. According to the North American Breeding Bird Survey, they declined on average by 3.2 percent per year between 1966 and 2010—a cumulative loss of more than 75 percent in that period. Partners in Flight estimates the global breeding population is 5.8 million, with 82 percent living in the U.S., 3 percent breeding in Canada, and 30 percent spending part of the year in Mexico. The 2014 State of the Birds Report listed them as a Common Bird in Steep Decline, and they rate an 11 out of 20 on the Partners in Flight Continental Concern Score. Loggerhead Shrikes have been listed as endangered, threatened, or of special concern in several states and Canada, and have been proposed for federal listing (the subspecies that nests on San Clemente Island, California, is listed as endangered). The species’ decline coincides with the introduction and increased use of chemical pesticides between the 1940s and the 1970s, and may result in part from the birds’ ingestion of pesticide-laced prey from treated fields. Other likely causes of population decline include collision with vehicles, urban development, conversion of hayfields and pastureland, decimation of hedgerows, habitat destruction by surface-coal strip-mining, and altering of prey populations by livestock grazing. Given this bird’s potentially high reproductive rate, and provided that adequate habitat continues to be available, Loggerhead Shrike populations may be able to recover if the causes of the bird’s decline can be identified and eliminated.
- Yosef, R. 1996. Loggerhead Shrike (Lanius ludovicianus). In The Birds of North America, No. 231 (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York.
- Dune, Pete. 2006. Pete Dunne’s Essential Field Guide Companion. Houghton Mifflin Company, Boston.
- Partners in Flight. 2012. Species assessment database.
- Tyler, J.D. 1991. Vertebrate prey of the Loggerhead Shrike in Oklahoma. Proceedings of the Oklahoma Academy of Science 71:17-20.
- USGS Patuxent Wildlife Research Center. 2012. North American Breeding Bird Survey 1966–2010 analysis.
- Wiggins, D.A. 2005. Loggerhead Shrike (Lanius ludovicianus): A Technical Conservation Assessment. Prepared for USDA Forest Service, Rocky Mountain Region, Species Conservation Project.
- The State of the Birds Report 2014
Migratory in the northern portion of its range, generally moving south of 40°N latitude to avoid significant snow cover. Loggerhead Shrikes apparently migrate individually and diurnally, moving short distances at a time and feeding en route.
Find This Bird
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. Loggerhead Shrikes also sometimes hover while hunting, so watch for hovering birds that seem too small to be American Kestrels.