Butcherbird
The Loggerhead shrike (Lanius ludovicianus) is a medium-sized songbird endemic to North America. It is nicknamed the butcherbird after its carnivorous tendencies, as it consumes prey such as amphibians, small birds, and even small mammals, and some prey ends up displayed and stored at a site, for example in a tree. Due to its small size and weak talons, this predatory bird relies on impaling its prey upon thorns or barbed wire for easier consumption.
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DiurnalDiurnal animals are active during the daytime, with a period of sleeping or other inactivity at night. The timing of activity by an animal depends ...
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CarnivoreA carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of a...
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InsectivoresAn insectivore is a carnivorous plant or animal that eats insects. An alternative term is entomophage, which also refers to the human practice of e...
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ArborealArboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some anima...
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Ambush predatorAmbush predators are carnivorous animals that capture or trap prey by stealth, luring, or by (typically instinctive) strategies utilizing an elemen...
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AltricialAltricial animals are those species whose newly hatched or born young are relatively immobile. They lack hair or down, are not able to obtain food ...
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TerrestrialTerrestrial animals are animals that live predominantly or entirely on land (e.g., cats, ants, snails), as compared with aquatic animals, which liv...
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OviparousOviparous animals are female animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive...
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TerritorialA territory is a sociographical area that which an animal consistently defends against the conspecific competition (or, occasionally, against anima...
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MonogamyMonogamy is a form of relationship in which both the male and the female has only one partner. This pair may cohabitate in an area or territory for...
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Generally solitaryGenerally solitary animals are those animals that spend their time separately but will gather at foraging areas or sleep in the same location or sh...
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Partial MigrantPartial migration is when within a migratory species or even within a single population, some individuals migrate while others do not.
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starts withThe adult plumage of the Loggerhead shrike is grey above with a white to pale grey breast and black tarsi and feet. The bird possesses a black mask that extends across the eyes to its bill. The wings are black with a distinct white patch on the primaries. The tail is black-edged with white and the irises are brown. The beak is short, black, and hooked, and contains a tomial tooth to help tear into prey. It is difficult to sex an adult loggerhead shrike in the field as they are sexually monochromatic. However, several studies have reported sexual dimorphism in plumage and size traits. Juveniles possess a paler gray plumage that is subtly vermiculated.
Loggerhead shrikes are found across southern Canada, much of the USA, and Mexico. Northern populations are migratory while birds from the southern part of their range are sedentary. Loggerhead shrikes require an open habitat with an area to forage, elevated perches, and nesting sites. They are often found in open pastures or grasslands and prefer red cedar and hawthorn trees for nesting. The hawthorn's thorns and the cedar's pin-like needles protect and conceal these birds from predators. They may also nest in fence rows or hedge rows near open pastures and require elevated perches as lookout points for hunting.
Loggerhead shrikes are diurnal birds that are usually seen alone. They establish feeding territories and defend them with advertising calls. Loggerhead shrikes are not true birds of prey, as they lack the large, strong talons used to catch and kill prey. Instead, they are sit-and-wait hunters that stalk prey by hawking and diving from elevated perches. By scanning their vicinity from a perch instead of flying, the shrike does not exhaust its energy during the search. Due to their small size in proportion to the size of their prey, shrikes must rely on specialized adaptations to facilitate their hunting. The powerful, hooked beak allows them to sever the neck of a small vertebrate. Larger prey are subjected to impaling, in which they are pushed down into a sharp projection, such as a thorn or barbed wire. Shrikes can then tear off flesh by using the projection as an anchor. They may also use the thorn to fasten and store their food to return to at a later time. Loggerhead shrikes communicate with the help of various calls which have been described as harsh and jarring. These include squeaky whistles, shrill trills, and guttural warbles. When alarmed, shrikes will produce a “schgra-a-a” shriek while spreading out their tail feathers. Nestlings will make “tcheek” and “tsp” sounds shortly after hatching. During courtship feedings, females may ask for food with “mak” begging notes; conversely, males emit “wuut” or “shack” sounds to offer food. Males emit a territorial, harsh shriek, while females' song is pitched lower and softer than the males'. Generally, males are far more vocal than females.
Loggerhead shrikes are carnivores (insectivores). They feed on insects but also consume arachnids, reptiles, amphibians, rodents, bats, and small birds.
Loggerhead shrikes form monogamous pairs and begin breeding during their first spring. During this time, the male performs a courtship ritual that occurs in flight. He dances erratically in the air, flying rapidly up and down and occasionally chasing the female. He presents himself to his potential mate by fanning out his tail and fluttering his wings. Females may respond to the fluttering display with begging notes, similar to those of juveniles begging for food; this encourages the male to feed her. Loggerhead shrikes nest in dense trees and shrubs. The female lays 4 to 8 eggs in a bulky cup made of twigs and grass. Incubation, on average, lasts 16 days. Once hatched, nestlings are fed by both the male and female parents. The average fledging period is about 19 days. Young may then remain nearby and depend on adults for 3 to 4 weeks. After that, they begin to forage independently.
Loggerhead shrike populations have been decreasing in North America since the 1960s. The reasons behind the decline remain unclear, although suggestions include habitat loss, pesticide contamination, climate change, pollution, and human disturbance.
According to the IUCN Red List, the total population size of the Loggerhead shrike is 7,000,000 mature individuals. Overall, currently, Loggerhead shrikes are classified as Near Threatened (NT) on the IUCN Red List, and their numbers today are decreasing.
