| Chihuahuan raven | |
|---|---|
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| Chihuahuan raven in Arizona | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Passeriformes |
| Family: | Corvidae |
| Genus: | Corvus |
| Species: | C. cryptoleucus |
| Binomial name | |
| Corvus cryptoleucus Couch, 1854 | |
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| Distribution map | |
The Chihuahuan raven (Corvus cryptoleucus) is a species of crow in the family Corvidae that is native to the United States and Mexico.
The proportions resemble the common raven with a heavy bill, but is about the same size as a carrion crow, or slightly larger than the American crow (44–51 cm (17–20 in) long). The plumage is all-black with a rich purple-blue gloss in good light. Like the forest raven, little raven, fan-tailed raven and Australian raven, it is one of the smaller raven species. The larger species of raven are the common raven, thick-billed raven, white-necked raven and brown-necked raven, with the common and thick-billed ravens being the world's largest raven species and the little and fan-tailed ravens being the smallest. The Chihuahuan raven is similar in appearance to the Australian raven, although with dark brown irises and whiter feather bases. The nasal bristles extend farther down the top of the bill than in any other Corvus species to about two-thirds the length. In addition, the Chihuahuan raven is similar in appearance to the white-necked raven of east Africa because the base of the neck has feathers that are white-ish (seen only when ruffled in strong wind). The bill, legs and feet are black.
The Chihuahuan raven occurs in the Southwestern and Midwestern United States and northern Mexico, including southeastern Arizona, southern New Mexico, southeastern Colorado, western Kansas, western Oklahoma, and southern and western Texas. [3]
It feeds on cultivated cereal grains, insects and many other invertebrates, small reptiles, carrion, cactus fruits, eggs and nestlings.
The nest is built in either trees, large shrubs or sometimes even in old buildings. There are usually 5–7 eggs laid relatively late in the year during May so as to take advantage of the insect food for their young in their more arid environment. Both the males and females incubate the eggs, feed the young, and remain territorial in protecting the nesting area. In rare cases, outsiders may be allowed into the territory to communally defend against potential predators.
The voice is similar to that of the common raven with "pruk-pruk" sounds and other croaks at slightly higher pitches. Like all corvids, the Chihuahuan raven is capable of vocal mimicry, however this behavior is mostly recorded in captivity and rarely in the wild.
A 2005 molecular study reviewed segments of DNA of the common raven and found that Chihuahuan raven are genetically nested within common ravens based on mitochondrial DNA. That is, common ravens from the California clade are more similar in mtDNA to Chihuahuan ravens than they are to common ravens in the Holarctic Clade. [4] [5]
A raven is any of several larger-bodied passerine bird species in the genus Corvus. These species do not form a single taxonomic group within the genus. There is no consistent distinction between crows and ravens. Names are assigned to different species chiefly based on their size.
Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, magpies, jackdaws, jays, treepies, choughs, and nutcrackers. In colloquial English, they are known as the crow family or corvids. Currently, 135 species are included in this family. The genus Corvus containing 47 species makes up over a third of the entire family. Corvids (ravens) are the largest passerines.
The carrion crow is a passerine bird of the family Corvidae and the genus Corvus which is native to western Europe and the eastern Palearctic.
The Australian raven is a passerine corvid bird native to Australia. Measuring 46–53 centimetres (18–21 in) in length, it has an all-black plumage, beak and mouth, as well as strong, greyish-black legs and feet. The upperparts of its body are glossy, with a purple-blue, greenish sheen; its black feathers have grey bases. The Australian raven is distinguished from the Australian crow, and other related corvids, by its long chest feathers, or throat hackles, which are prominent in mature birds. Older individuals and subadults have white irises, while the younger birds' eyes display blue inner rims; hatchlings and young birds have brown, dark irises until about fifteen months of age, at which point their irises become hazel-coloured, with an inner blue rim around each pupil, this lasting until they are roughly 2.5 to 3 years of age. Nicholas Aylward Vigors and Thomas Horsfield described the Australian raven in 1827, its species name coronoides highlighting its similarity with the carrion crow. Two subspecies are recognised, which differ slightly in their vocalisations, and are quite divergent, genetically.
The Torresian crow, also called the Australian crow or Papuan crow, is a passerine bird in the crow family native to the north and west of Australia and nearby islands in Indonesia and Papua New Guinea. The species has a black plumage, beak and mouth with white irises. The base of the feathers on the head and neck are white. The Torresian crow is slightly larger with a more robust bill than the morphologically similar little crow.
The forest raven, also commonly known as the Tasmanian raven, is a passerine bird in the family Corvidae native to Tasmania and parts of southern Victoria, such as Wilsons Promontory and Portland. Populations are also found in parts of New South Wales, including Dorrigo and Armidale. Measuring 50–53 cm (20–21 in) in length, it has all-black plumage, beak and legs. As with the other two species of raven in Australia, its black feathers have grey bases. Adults have white irises; younger birds have dark brown and then hazel irises with an inner blue rim. New South Wales populations are recognised as a separate subspecies C. tasmanicus boreus, but appear to be nested within the Tasmanian subspecies genetically.
The little raven is a species of the family Corvidae that is native to southeastern Australia. An adult individual is about 48–50 cm (19–19.5 in) in length, with completely black plumage, beak, and legs; as with all Australian species of Corvus, the black feathers have a grey base, and the iris of the adult bird is white . Although the little raven was first named by Gregory Mathews in 1912, it was only in 1967 that there was consensus to separate it from the Australian raven as a distinct species.
The thick-billed raven, a corvid from the Horn of Africa, shares with the common raven the distinction of being the largest bird in the corvid family, and indeed the largest of the passerines. The thick-billed raven averages 64 cm (25 in) in length, with a range of 60 to 70 cm and weighs approximately 1.15 kg (2.5 lb) in females and 1.5 kg (3.3 lb) in males on average. Its size is about the same as the largest subspecies of common raven but some common raven subspecies are rather smaller and, going on average weights, the thick-billed raven is likely the heaviest extant passerine. The thick-billed raven is about 25% heavier on average than the Australasian superb lyrebird, which is sometimes erroneously titled the largest passerine.
The pied crow is a widely distributed African bird species in the crow genus of the family Corvidae.
The American crow is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America. American crows are the New World counterpart to the carrion crow and the hooded crow of Eurasia; they all occupy the same ecological niche. Although the American crow and the hooded crow are very similar in size, structure and behavior, their calls and visual appearance are different.
The white-necked raven is a species of raven native to eastern and southern Africa. It is somewhat smaller than the common raven or its nearest relative, the thick-billed raven C. crassirostris.
The Daurian jackdaw is a bird in the crow family, Corvidae, native to eastern Asia. It is closely related to the western jackdaw. The name derives from the Dauria region of eastern Russia.
The Tamaulipas crow is a crow found in northeastern Mexico and southern Texas.
The fan-tailed raven is a passerine bird of the crow family native to Eastern Africa and the Arabian Peninsula.
The brown-necked raven is a larger bird than the carrion crow though not as large as the common raven. It has similar proportions to the common raven but the bill is not so large or deep and the wings tend to be a little more pointed in profile. The head and throat are a distinct brownish-black giving the bird its English name, while the rest of the plumage is black glossed with purple, blue or purplish-blue. Like the common raven, thick-billed raven and white-necked raven, it is one of the larger raven species. The feathers of this species often fade quite quickly to a brownish black and the bird can look distinctly brown by the time it moults. The feet, legs and bill are black. The dwarf raven was formerly considered a subspecies but this bird now appears to be closer to the pied crow than this species.
The large-billed crow, formerly referred to widely as the jungle crow, is a widespread Asian species of crow. It is very adaptable and is able to survive on a wide range of food sources, making it capable of colonizing new areas, due to which it is often considered a nuisance, especially on islands. It has a large bill, which is the source of its scientific name macrorhynchos and it is sometimes known by the common name thick-billed crow. It can also be mistaken for a common raven. Johann Georg Wagler first described the species from a holotype obtained from Java in the year 1827. The eastern jungle crow and Indian jungle crow were once considered conspecific and together called the jungle crow.
The common raven is a large all-black passerine bird. It is the most widely distributed of all corvids, found across the Northern Hemisphere. It is a raven known by many names at the subspecies level; there are at least eight subspecies with little variation in appearance, although recent research has demonstrated significant genetic differences among populations from various regions. It is one of the two largest corvids, alongside the thick-billed raven, and is possibly the heaviest passerine bird; at maturity, the common raven averages 63 centimetres in length and 1.47 kilograms in mass. Although their typical lifespan is considerably shorter, common ravens can live more than 23 years in the wild. Young birds may travel in flocks but later mate for life, with each mated pair defending a territory.
The Indian jungle crow is a species of crow found across the Indian Subcontinent south of the Himalayas. It is very common and readily distinguished from the house crow, which has a grey neck. In the past the species was treated as a subspecies of another crow species, but vocalizations and evidence from ectoparasite co-evolution and phylogenetic evidence have led to it being considered as a distinct species in modern taxonomic treatments. It differs in its voice from the large-billed crow found in the higher elevations of the Himalayas and the eastern jungle crow overlaps in the eastern part of its range. In appearance, it can be difficult to distinguish from either of these species although the plumage tends to be more uniformly glossed in purple and has a longer bill with a fine tip and a less arched culmen. The Himalayan species has a slightly wedge-shaped tail, unlike the rounded tail of the Indian jungle crow and tends to glide a lot.
The Somali crow, or dwarf raven, is approximately the size of the carrion crow, Corvus corone but with a longer bill and a somewhat more brownish cast to the feathers, especially when worn.
