Red-breasted Nuthatch | |
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Female | |
Conservation status | |
Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Family: | Sittidae |
Genus: | Sitta |
Species: | S. canadensis |
Binomial name | |
Sitta canadensis Linnaeus, 1766 |
The Red-breasted Nuthatch, Sitta canadensis, is a small songbird. The adult has blue-grey upperparts with cinnamon underparts, a white throat and face with a black stripe through the eyes, a straight grey bill and a black crown. Its call, which has been likened to a tin trumpet, is high-pitched and nasal. It breeds in coniferous forests across Canada, Alaska and the northeastern and western United States. Though often a permanent resident, it regularly irrupts further south if its food supply fails. There are records of vagrants occurring as far south as the Gulf Coast and northern Mexico. It forages on the trunks and large branches of trees, often descending head first, sometimes catching insects in flight. Its eat mainly insects and seeds, especially from conifers. It excavates a nest in dead wood, often close to the ground, smearing the entrance to their nest with pitch.
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Like all nuthatches, the Red-breasted Nuthatch is assigned to the genus Sitta (Linnaeus, 1758),[2] a name derived from sittē (σιττη), the Ancient Greek word for the Eurasian Nuthatch. The specific epithet canadensis is New Latin for "belonging to Canada".[3] The species was given its scientific name by Carl Linnaeus in 1766, based on a specimen collected in Canada.[4] "Nuthatch" is a linguistic corruption of "nuthack", referring to the bird's habit of wedging nuts into cracks in tree bark and hacking at them until they break open.[5] "Red-breasted" is a reference to the rusty colour of the male's underparts.[3]
In the past, the Red-breasted Nuthatch and four other species — the Corsican Nuthatch, the Chinese Nuthatch, the Algerian Nuthatch and the Krüper's Nuthatch — were thought to be a single species.[6] These five make up a well-defined species group known as the "Sitta canadensis group", and are sometimes considered to be a superspecies.[4] Within the species group, DNA studies have shown that the Red-breasted Nuthatch, the Corsican Nuthatch and the Chinese Nuthatch make up one clade and the Algerian Nuthatch and Krüper's Nuthatch make up a sister clade.[7] The Red-breasted Nuthatch is monotypic across its extensive range.[4]
The Red-breasted Nuthatch is a small passerine, measuring 4.5 in (11 cm) in length,[nb 1][9] with a wingspan of 8.5 in (22 cm)and a weight of 0.35 oz (10 g).[10] Its back and uppertail are bluish, and its underparts rust-colored. It has a black cap and eye line and a white supercilium (eyebrow). Sexes are similarly plumaged, though females and youngsters have duller heads and paler underparts.[9]
The Red-breasted Nuthatch's call is high-pitched, nasal and weak. Transcribed as yenk or ink,[10] they have been likened to a toy tin horn[9] or a child's noisemaker.[11] Its song is a slowly repeated series of clear, nasal, rising notes, transcribed as eeen eeen eeen.[10]
Though it is primarily a fulltime resident of northern and subalpine conifer forests, the Red-breasted Nuthatch regularly migrates irruptively, with both the number migrating and the wintering locations varying from year to year.[9] They sometimes reach northern Mexico, where they are rare winter visitors to Nuevo Leon, Baja California Norte and south along the Pacific slope as far as Sinaloa.[12] In the eastern United States, its range is expanding southwards.[9] Though formerly resident on Isla Guadalupe, an island off the western coast of Mexico, it appears to have been extirpated there, with the last known record of the species on the island dating from 1971. There is a single vagrant record for Mexico's Isla Socorro.[12] It is an extremely rare vagrant to Europe, with two records in the western Palearctic; one bird successfully overwintered in eastern England.[13]
Like all nuthatches, the Red-breasted Nuthatch is an acrobatic species, hitching itself up and down tree trunks and branches.[9] Unlike woodpeckers and creepers, it does not use its tail as a prop while climbing.[14] It tends to be found singly or in pairs, and forages from low to high on tree trunks and branches.[12]
The Red-breasted Nuthatch's diet changes depending on the season. In the summer, it eats mostly insects, occasionally even flycatching, while in the winter, it switches to conifer seeds.[15]
The Red-breasted Nuthatch, like all nuthatches, is monogamous. It excavates its own cavity nest, taking one to eight weeks to do so[16] and smears sap around the entrance hole, presumably to help deter predators.[14] The female lays 2–8 eggs, which are white, creamy or pinkish, and covered with reddish-brown speckles; the eggs measure 0.6–0.7 in (1.5–1.8 cm) long by 0.4–0.5 in (1.0–1.3 cm) wide, and are incubated for 12–13 days.[17]
Because of its large global range and its increasing population, the Red-breasted Nuthatch is rated as a species of Least Concern by the International Union for Conservation of Nature.[1] In the Americas, it is protected by the Migratory Bird Treaty Act of 1918.[18]