Loggerhead shrike
The loggerhead shrike (Lanius ludovicianus), sometimes called a butcherbird, is a small predatory songbird, noted for its practice of impaling its prey on thorns or similar objects to facilitate eating, or as a means of storage or display.
The species is endemic to much of North America and is present in Alabama year-round. It is typically smaller and darker-colored than the related northern shrike, with a larger black face mask and shorter bill. The common name "shrike", in use in English from at least the 16th century, related to the bird's shriek-like call, and the descriptor "loggerhead" is generally equivalent to "blockhead," and likely refers to the bird's proportionally large head, though even in the 16th century the term was commonly used to describe a stupid person.
European shrikes had been collected under the Latin name "Lanius" (butcher) since the 10th edition of Carl Linnaeus' Systema Naturae in 1758. French ornithologist Mathurin-Jacques Brisson collected a specimen in Louisiana, which he described as a "La pie-grièche de la Louisiane" (using the common French term for shrike which translates roughly as "Greek magpie.") He proposed the Latin Lanius ludovicianus (Louis' butcher) in his 1760 6-volume study. Brisson's coinage was adopted by Linnaeus in the 12th edition of his Systema in 1766.
Physical characteristics
Male and female loggerhead shrikes have a dark gray crown and back with a light-colored chin and chest and black marking the ends of their wings and tails, with distinct white patches on their wings. Their heads are large in proportion to their bodies, and are divided by a black mask extending back from the black slightly-hooked beak and around the eyes. The legs and feet are also dark colored. Loggerhead shrikes range from about 8 to 9 inches in length with an 11 to 12.6-inch wingspan. Adult shrikes generally weight in at 45-60 grams (1.6 to 2.1 ounces). Juveniles generally show less striking color contrasts with subtle vermiculation.
Shrike calls are typically loud, high-pitched and jarring, with a variety of whoops, whistles, trills and warbles. Loud calls of alarm are accompanied by displays of spread tail feathers. Gentler vocalizations are employed in close interactions between mates, parents and young.
Range and habitat
Generally, the subspecies Lanius ludovicianus ludovicianus occupies the southeastern United States, with some overlap and intergradation making it difficult to distinguish from the less common "migrant loggerhead shrike" (Lanius ludovicianus migrans), which once migrated between Canada and New England to the mid-Atlantic states, but is now largely confined to the southern portion of its historic range. Five other subspecies are recorded in western North America, Canada and Mexico.
Loggerhead shrikes hunt and forage in open areas with low ground cover and with access to elevated perches and nesting sites with expansive views. They are often found in open pastures or grasslands. In urban areas they may occupy large vacant lots, golf courses or cemeteries. Shrikes take advantage of access to thorny, woody plants or barbed-wire fencing as part of their hunting behavior.
Behavior
Diet
Loggerhead shrikes primarily prey on large insects such as crickets, which they hunt during the day from elevated perches, generally 12-14 feet above ground. Sometimes if they lose sight of prey during flight they will seem to hover briefly, like a kestrel.
Shrikes routinely pursue larger prey, including reptiles, amphibians, rodents, bats and smaller birds, by spearing and immobilizing them with their sharp, hooked beaks and with swift, strong head strikes aimed at the necks of vertebrates. They can carry larger prey to available thorns, sharp twigs or barbed-wire fences to impale them, allowing them to store food over time or to present it to potential mates. In some cases, caching may help the poisons in certain animals to break down before consumption. When opportunities arise, shrikes may also scavenge from carcasses or store food discarded by humans.
Shrikes are known to steal such caches from their peers. Some shrikes never adopt the species' unusual impalement strategy.
Reproduction
Shrikes breed during their first spring and are generally monogamous. The males court female partners with displays of skilled flying, sometimes chasing the females and displaying his wing and tail feathers. Females respond with sounds similar to those made by hungry fledglings, inviting the male to bring her food.
Shrikes construct bulky cup-shaped nests of twigs and grass, lined with softer materials. The female builds the next from materials gathered by both partners. They favor the protection offered by evergreen trees for nesting, but will also nest in hedges or overgrown fence rows, particularly those with briars. Females lay clutches of 4 to 8 eggs which incubate for a little over two weeks and hatch over the course of a few days. Both parents bring food to the hatchlings until they leave the nest, in a little under three weeks. They remain dependent on their parents for 3 to 4 weeks after leaving the nest and mimic their parents' hunting and collecting behaviors.
Conservation status
The migrant loggerhead shrike subspecies has declined greatly from its former range across eastern Canada and the northeastern United States and is considered critically endangered in Canada, where conservationists are endeavoring to reintroduce it to the wild. It is also rarely seen in New England and it is difficult to distinguish migrant loggerhead shrikes from the more southerly resident population in the mid-Atlantic states. They remain common in the Southeast.
Over their entire historic range, loggerhead shrikes have diminished by a little over 3 percent each year between 1966 and 2010. This is attributed primarily to pesticide-laced prey and to habitat loss.
References
- "Loggerhead shrike" (November 7, 2023) Wikipedia - accessed December 28, 2023
- Pillion, Dennis (December 27, 2023) "This bird looks cute, acts like a serial killer and is one of Alabama’s weirdest animals." AL.com
External links
- Loggerhead shrike at allaboutbirds.org
- Loggerhead shrike at audubon.org
- Loggerhead shrike at ecos.fws.gov