Corvidae
Encyclopedia
Corvidae is a cosmopolitan
family
of oscine passerine
birds that contains the crow
s, raven
s, rook
s, jackdaw
s, jay
s, magpie
s, treepie
s, choughs and nutcrackers
. The common English names used are corvids (more technically) or the crow family (more informally), and there are over 120 species. The genus Corvus, including the jackdaws, crows and ravens, makes up over a third of the entire family.
They are considered the most intelligent of the birds, and among the most intelligent of all animals having demonstrated self-awareness
in mirror tests (European Magpie
s) and tool making ability (Crows, Rooks)—skills until recently regarded as solely the province of humans and a few other higher mammals. Their total brain to body ratio is equal to that of great apes and cetaceans, and only slightly lower than in humans.
They are medium to large in size, with strong feet and bills, rictal bristles and a single moult
each year (most passerines moult twice). Corvids are found worldwide except for the tip of South America and the polar ice caps. The majority of the species are found in tropical South and Central America, southern Asia and Eurasia, with fewer than 10 species each in Africa, Australasia and North America. The genus Corvus has re-entered Australia in relatively recent geological prehistory, with five species and one subspecies there.
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Over the years there has been much disagreement on the exact evolutionary relationships of the corvid family and their relatives. What eventually seemed clear was that corvids are derived from Australasia
n ancestors and from there spread throughout the world. Other lineages derived from these ancestors evolved into ecologically diverse, but often Australasian groups. In the late 1970s and throughout the 1980s Sibley and Ahlquist
united the corvids with other taxa in the Corvida
, based on DNA-DNA hybridization. The presumed corvid relatives included currawong
s, birds of paradise, whipbirds, quail-thrush
es, whistlers
, monarch flycatchers and drongo
s, shrike
s, vireo
s and vanga
s, but current research favors the theory that this grouping is partly artificial. The corvids constitute the core group of the Corvoidea, together with their closest relatives (the birds of paradise, Australian mud-nesters and shrikes). They are also the core group of the Corvida, which includes the related groups, such as oriole
s and vireos.
Clarification of the interrelationships of the corvids has been achieved based on cladistic analysis of several DNA sequence
s. The jays and magpies do not constitute monophyletic lineages, but rather seem to split up into an American
and Old World
lineage, and an Holarctic
and Oriental lineage, respectively. These are not closely related among each other. The position of the Azure-winged Magpie
, which has always been a major enigma, is even less clear than before.
FAMILY CORVIDAE
The Crested Jay
(Platylophus galericulatus) is traditionally included in the Corvidae, but might not be a true member of this family, possibly being closer to the helmet-shrikes
(Malaconotidae) or shrike
s (Laniidae); it is best considered Corvidae incertae sedis
for the time being. Likewise, the Hume's Ground "Jay"
(Pseudopodoces humilis) is in fact a member of the tit family Paridae.
s date to the mid-Miocene
, about 17 million years ago; Miocorvus and Miopica may be ancestral to crows and some of the magpie lineage, respectively, or similar to the living forms due to convergent evolution
. The known prehistoric corvid genera appear to be mainly of the New World and Old World jay and Holarctic magpie lineages:
In addition, there are numerous fossil species of extant genera since the Mio
–Pliocene
, mainly European Corvus.
s with a robust build, strong legs and all species except the Pinyon Jay
have nostril
s covered by bristle-like feathers. Many corvids of temperate zones have mainly black or blue coloured plumage
; however, some are pied black and white, some have a blue-purple iridescence and many tropical species are brightly coloured. The sexes are very similar in color and size. Corvids have strong, stout bills and large wingspans. The family includes the largest members of the passerine
order.
The smallest corvid is the Dwarf Jay
(Aphelocoma nana), at 40 g (1.4 oz) and 21.5 cm (8.5 inches). The largest corvids are the Common Raven
(Corvus corax) and the Thick-billed Raven
(Corvus crassirostris), both of which regularly exceed 1400 grams (3 lbs) and 65 cm (26 inches).
Species can be identified based on size, shape, and geography; however, some, especially the Australian crows, are best identified by their raucous calls.
significantly. However, during a shortage of food, eruptive migration can occur. When species are migratory, they will form large flocks in the fall (around August in the northern hemisphere
) and travel south.
One reason for the success of crows, compared to ravens, is their ability to overlap breeding territory. During breeding season, crows were shown to overlap breeding territory six times as much as ravens. This invasion of breeding ranges allowed a related increase in local population density.
The natural diet of many corvid species is omnivorous, consisting of invertebrate
s, nestlings, small mammals, berries, fruits, seeds, and carrion
. However, some corvids, especially the crows, have adapted well to human conditions and have come to rely on anthropogenic foods. In a US study of American Crow
s, Common Raven
s and Steller's Jay
s around campgrounds and human settlements, the crows appeared to have the most diverse diet of all, taking anthropogenic foods such as bread, spaghetti, fried potatoes, dog food, sandwiches, and livestock feed. The increase in available anthropogenic food sources is contributing to population increase in some corvid species.
Some corvids are predators of other birds. During the wintering months, corvids typically form foraging flocks. However, some crows also eat many agricultural pests including cutworms, wireworms, grasshoppers, and harmful weeds Some corvids will eat carrion, and since they lack a specialized beak for tearing into flesh, they must wait until animals are opened, whether by other predators or as roadkill.
Since crows do not seem to mind human development, it was suggested that the crow population increase would cause increased rates of nest predation. However, Steller's Jays, which are successful independently of human development, are more efficient in plundering small birds' nests than American Crow
s and Common Raven
s. Therefore, the human relationship with crows and ravens did not significantly increase nest predation, compared to other factors such as habitat destruction
.
Many species of corvid are territorial
, protecting territories throughout the year or simply during the breeding season. In some cases territories may only be guarded during the day, with the pair joining off-territory roosts at night. Some corvids are well known communal roosters. Some groups of roosting corvids can be very large, with a roost of 65,000 Rooks
counted in Scotland. Some, including the Rook and the Jackdaw
, are also communal nesters.
The partner bond in corvids is extremely strong and even lifelong in some species. This monogamous lifestyle, however, can still contain extra-pair copulations. Males and females build large nests together in trees or on ledges. The male will also feed the female during incubation. The nests are constructed of a mass of bulky twigs lined with grass and bark. Corvids can lay between 3 and 10 eggs, typically ranging between 4 and 7. The eggs are usually greenish in colour with brown blotches. Once hatched, the young remain in the nests for up to 6–10 weeks depending on the species. Corvids provide biparental care.
Jackdaws can breed in buildings or in rabbit warrens. White-throated Magpie-jay
s are cooperatively breeding corvids where the helpers are mostly female. Cooperative breeding
takes place when additional adults help raise the nestlings. Such helpers at the nest
in most cooperatively breeding birds are males, while females join other groups.
Young corvids have been known to play and take part in elaborate social game
s. Documented group games follow a "king of the mountain"- and "follow the leader"-type pattern. Other play
involves the manipulation, passing, and balancing of sticks. Corvids also take part in other activities, such as sliding down smooth surfaces. These games are understood to play a large role in the adaptive and survival ability of the birds.
Mate selection is quite complex and accompanied with much social play in the Corvidae. Youngsters of social corvid species undergo a series of tests, including aerobatic feats, before being accepted as a mate by the opposite sex.
Some corvids can be aggressive. Blue Jay
s, for example, are well known to attack anything that threatens their nest. Crows have been known to attack dogs, cats, ravens, and birds of prey. Most of the time these assaults take place as a distraction long enough to allow an opportunity for stealing food.
When compared to dogs and cats in an experiment testing the ability to seek out food according to three-dimensional clues, corvids out-performed the mammals. A metaanalysis testing how often birds invented new ways to acquire food in the wild found corvids the most innovative birds. A 2004 review suggests that their cognitive abilities are on par with those of great apes. Despite structural differences, the brains of corvids and great apes both evolved the ability to make geometrical measurements.
Corvid ingenuity is represented through their feeding skills, memorization abilities, use of tools, and group behaviour. Living in large social groups has long been connected with high cognitive ability. To live in a large group, a member must be able to recognize individuals and track the social position and foraging of other members over time. Members must also be able to distinguish between sex, age, reproductive status, and dominance, and to update this information constantly. It might be that social complexity corresponds to their high cognition.
The European Magpie
is one of the few non-mammal species known to be able to recognize itself in a mirror test
.
There are also specific examples of corvid cleverness. One Carrion Crow
was documented to crack nuts by placing them on a crosswalk, letting the passing cars crack the shell, waiting for the light to turn red, and then safely retrieving the contents. A group of crows in England took turns lifting garbage bin lids while their companions collected food.
Members of the corvid family have been known to watch other birds, remember where they hide their food, then return once the owner leaves. Corvids also move their food around between hiding places to avoid thievery, but only if they have previously been thieves themselves i.e., they remember previous relevant social contexts, use their own experience of having been a thief to predict the behavior of a pilferer, and can determine the safest course to protect their caches from being pilfered. Studies to assess similar cognitive abilities in apes have been inconclusive.
The ability to hide food requires highly accurate spatial memories. Corvids have been recorded to recall their food's hiding place up to nine months later. It is suggested that vertical landmarks (like trees) are used to remember locations. There has also been evidence that Western Scrub-Jays, which store perishable foods, not only remember where they stored their food, but for how long. This has been compared to episodic memory, previously thought unique to humans.
New Caledonian Crow
s (Corvus moneduloides) are notable for their highly developed tool fabrication. They make angling tools of twigs and leaves trimmed into hooks, then use the hooks to pull insect larvae from tree holes. Tools are engineered according to task and apparently also to learned preference. Recent studies revealed abilities to solve complicated problems, which suggests high level of innovation of a complex nature. Other corvids that have been observed using tools include the American Crow
, Blue Jay
and Green Jay
. Diversity in tool design among corvids suggests cultural variation. Again, great apes are the only other animals known to use tools in such a fashion.
Clark's Nutcracker
s and Jackdaw
s were compared in a 2002 study based on geometric rule learning. The corvids, along with a domestic pigeon
, had to locate a target between two landmarks, while distances and landmarks were altered. The nutcrackers were more accurate in their searches than the jackdaws and pigeons.
The scarecrow
is an archetypal scare tactic in the agricultural business. However, due to corvids' quick wit, scarecrows are soon ignored and used as perches. Despite farmers' efforts to rid themselves of corvid pests, their attempts have only expanded corvid territories and strengthened their numbers.
Current systematics
places corvids, based on physical characteristics other than their brains (the most developed of birds), in the lower middle of the passerines, contrary to earlier teleological classifications as "highest" songbirds due to their intelligence. As per one observer:
The other major group of highly intelligent birds of the order Psittaciformes (which includes 'true' parrots, cockatoo
s and New Zealand parrots) is not closely related to corvids.
in the USA. They are infected by mosquitoes (the vectors), primarily of the Culex
species. Crow
s and Raven
s are quickly killed by this disease, so their deaths are an early-warning system when West Nile Virus arrives in an area (as are horse and other bird species deaths). One of the first signs that West Nile Virus first arrived in the USA in 1999 was the death of crows in New York.
s, have occasionally served as pets
, although they are not able to speak as readily as parrot
s and do not like being caged.
Various Germanic peoples
highly revered the raven. The major deity Odin
was so associated with ravens throughout history that he gained the kenning
"raven god" and the raven banner
was the flag of various Viking Age
Scandinavian chieftains. He was also attended by Hugin and Munin
, two ravens
who whispered news into his ears. The Valravn
sometimes appears in modern Scandinavian folklore.
The 6th century BC Greek
scribe Aesop
featured corvids as intelligent antagonists in many fables. Later, in western literature, popularized by American poet Edgar Allan Poe
's work "The Raven
", the Common Raven
becomes a symbol of the main character's descent into madness.
Unlike many other bird families
, corvid fitness
and reproduction, especially with many crows, has increased due to human development. The survival and reproductive success of certain crows and ravens is assisted by their close relationship with humans.
Human development provides additional resources by clearing land, creating shrublands rich in berries and insects. When the cleared land naturally replenishes, jays and crows use the young dense trees for nesting sites. Ravens typically use larger trees in denser forests.
Despite the fact that most corvids are not threatened (many even increasing due to human activity) a few species are in danger. For example, the destruction of the Southeast Asian rainforests is endangering mixed-species feeding flock
s with members from the family Corvidae. Also, since its semiarid scrubland habitat
is an endangered ecosystem
, the Florida Scrub-jay has a small and declining population. A number of island species, which are more vulnerable to introduced species
and habitat loss, have been driven to extinction, such as the New Zealand Raven
, or are threatened, like the Mariana Crow
.
The American Crow
population of the United States has grown over the years. It is possible that the American Crow, due to humans increasing suitable habitat, will drive out Northwestern
and Fish Crow
s.
36: 222-234. PDF fulltext (2003) Ornithology (2nd edition). W.H. Freeman and Company, New York. ISBN 0-7167-2415-4 (1986) Crows of the world. (2nd edition). British Museum of Natural History. ISBN 0-565-00979-6 (2003): Pseudopodoces humilis, a misclassified terrestrial tit (Aves: Paridae) of the Tibetan Plateau: evolutionary consequences of shifting adaptive zones. Ibis
145(2): 185–202. PDF fulltext (2002): A Comparative Study of Geometric Rule Learning by Nutcrackers (Nucifraga columbiana), Pigeons (Columba livia), and Jackdaws (Corvus monedula). Journal of Comparative Psychology 116(4): 350-356. HTML abstract PDF fulltext (2006): A phylogenetic supertree of oscine passerine birds (Aves: Passeri). Zool. Scripta
35(2): 149–186. (HTML abstract) (1979): [Ability of birds of the Corvidae family to operate by the empirical dimensions of figures]. Zhurnal vysshe nervno deiatelnosti imeni IP Pavlova 29(3): 590-597. [Article in Russian] PMID 112801 (HTML abstract) (2000): High frequency of extrapair fertilization in a plural breeding bird, the Mexican jay, revealed by DNA microsatellites. Animal Behaviour 60(6): 867-877 (2005): Effects of habitat disturbance on mixed species bird flocks in a tropical sub-montane rainforest. Biological Conservation 122(2): 193-204. (HTML abstract) (1993): Crows and Jays. Helm. ISBN 1-873403-18-6 (2005): In the Company of Crows and Ravens. Yale University Press, New Haven, Connecticut. ISBN 0-300-10076-0 (2006): Corvid response to human settlements and campgrounds: Causes, consequences, and challenges for conservation. Biological Conservation 130(2): 301-314. (HTML abstract) (1971): Ecological studies of the Rook Corvus frugilegus L. in northeast Scotland. Dispersion. J. Appl. Ecol. 8: 815-833.: The New Encyclopedia of Birds Oxford University Press: Oxford ISBN 0-19-852506-0 (2000): Bird Families of the World: Corvidae. Created 2000-JAN-30. Retrieved 2007-NOV-10. ([1991]): Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale University Press, New Haven, Connecticut. ISBN 0-300-04085-7 (2004): Why fight? Socially dominant jackdaws, Corvus monedula, have low fitness. Animal Behaviour 68: 777-783. (HTML abstract) (1937): The Eared Grebe and other Birds from the Pliocene of Kansas. Condor
39(1): 40. PDF fulltext DjVu fulltext
Cosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
of oscine passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
birds that contains the crow
Crow
Crows form the genus Corvus in the family Corvidae. Ranging in size from the relatively small pigeon-size jackdaws to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents and several...
s, raven
Raven
Raven is the common name given to several larger-bodied members of the genus Corvus—but in Europe and North America the Common Raven is normally implied...
s, rook
Rook (bird)
The Rook is a member of the Corvidae family in the passerine order of birds. Named by Carl Linnaeus in 1758, the species name frugilegus is Latin for "food-gathering"....
s, jackdaw
Jackdaw
The Jackdaw , sometimes known as the Eurasian Jackdaw, European Jackdaw or Western Jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa, it is mostly sedentary, although northern and eastern populations migrate south in winter. Four subspecies are...
s, jay
Jay
The jays are several species of medium-sized, usually colorful and noisy, passerine birds in the crow family Corvidae. The names jay and magpie are somewhat interchangeable, and the evolutionary relationships are rather complex...
s, magpie
Magpie
Magpies are passerine birds of the crow family, Corvidae.In Europe, "magpie" is often used by English speakers as a synonym for the European Magpie, as there are no other magpies in Europe outside Iberia...
s, treepie
Treepie
The treepies comprise four closely related genera of long-tailed passerine birds in the family Corvidae...
s, choughs and nutcrackers
Nutcracker (bird)
The nutcrackers are a genus of two species of passerine bird, in the family Corvidae, related to the jays and crows. One, the Spotted Nutcracker , occurs in Europe and Asia, the other, Clark's Nutcracker , in western North America.The most important food resources for both these species are the...
. The common English names used are corvids (more technically) or the crow family (more informally), and there are over 120 species. The genus Corvus, including the jackdaws, crows and ravens, makes up over a third of the entire family.
They are considered the most intelligent of the birds, and among the most intelligent of all animals having demonstrated self-awareness
Self-awareness
Self-awareness is the capacity for introspection and the ability to reconcile oneself as an individual separate from the environment and other individuals...
in mirror tests (European Magpie
European Magpie
The European Magpie, Eurasian Magpie, or Common Magpie, , is a resident breeding bird throughout Europe, much of Asia and northwest Africa. It is one of several birds in the crow family named as magpies, and belongs to the Holarctic radiation of "monochrome" magpies...
s) and tool making ability (Crows, Rooks)—skills until recently regarded as solely the province of humans and a few other higher mammals. Their total brain to body ratio is equal to that of great apes and cetaceans, and only slightly lower than in humans.
They are medium to large in size, with strong feet and bills, rictal bristles and a single moult
Moult
In biology, moulting or molting , also known as sloughing, shedding, or for some species, ecdysis, is the manner in which an animal routinely casts off a part of its body , either at specific times of year, or at specific points in its life cycle.Moulting can involve the epidermis , pelage...
each year (most passerines moult twice). Corvids are found worldwide except for the tip of South America and the polar ice caps. The majority of the species are found in tropical South and Central America, southern Asia and Eurasia, with fewer than 10 species each in Africa, Australasia and North America. The genus Corvus has re-entered Australia in relatively recent geological prehistory, with five species and one subspecies there.
Systematics, taxonomy and evolution
Australasia
Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...
n ancestors and from there spread throughout the world. Other lineages derived from these ancestors evolved into ecologically diverse, but often Australasian groups. In the late 1970s and throughout the 1980s Sibley and Ahlquist
Sibley-Ahlquist taxonomy
The Sibley-Ahlquist taxonomy is a bird taxonomy proposed by Charles Sibley and Jon Edward Ahlquist. It is based on DNA-DNA hybridization studies conducted in the late 1970s and throughout the 1980s....
united the corvids with other taxa in the Corvida
Corvida
The "Corvida" were one of two "parvorders" contained within the suborder Passeri, as proposed in the Sibley-Ahlquist taxonomy. Standard taxonomic practice would place them at the rank of infraorder....
, based on DNA-DNA hybridization. The presumed corvid relatives included currawong
Currawong
Currawongs are three species of medium-sized passerine birds belonging to the genus Strepera in the family Artamidae native to Australasia. These are the Grey Currawong , Pied Currawong , and Black Currawong . The common name comes from the call of the familiar Pied Currawong of eastern Australia...
s, birds of paradise, whipbirds, quail-thrush
Quail-thrush
Quail-thrush is the term applied to any member of the genus Cinclosoma, which contains five species of birds who are related to neither quails nor thrushes though have characteristics of both. The genus is found in Australia and New Guinea in a variety of habitats ranging from rainforest to deserts...
es, whistlers
Pachycephalidae
The family Pachycephalidae, collectively the whistlers, includes the whistlers, shrike-thrushes, shrike-tits, pitohuis and Crested Bellbird, and is part of the ancient Australo-Papuan radiation of songbirds. Its members range from small to medium in size, and occupy most of Australasia...
, monarch flycatchers and drongo
Drongo
The drongos are a family of small passerine birds of the Old World tropics, the Dicruridae. This family was sometimes much enlarged to include a number of largely Australasian groups, such as the Australasian fantails, monarchs and paradise flycatchers...
s, shrike
Shrike
Shrikes are passerine birds of the family Laniidae. The family is composed of thirty-one species in three genera. The family name, and that of the largest genus, Lanius, is derived from the Latin word for "butcher", and some shrikes were also known as "butcher birds" because of their feeding habits...
s, vireo
Vireo
The vireos are a group of small to medium-sized passerine birds restricted to the New World. They are typically dull-plumaged and greenish in color, the smaller species resembling wood warblers apart from their heavier bills...
s and vanga
Vanga
The vangas are a group of little-known small to medium-sized passerine birds restricted to Madagascar and the Comoros. They are usually classified as the family Vangidae. There are about 22 species, depending on taxonomy...
s, but current research favors the theory that this grouping is partly artificial. The corvids constitute the core group of the Corvoidea, together with their closest relatives (the birds of paradise, Australian mud-nesters and shrikes). They are also the core group of the Corvida, which includes the related groups, such as oriole
Oriole
Orioles are colourful Old World passerine birds in the genus Oriolus, the namesake of the corvoidean family Oriolidae. They are not related to the New World orioles, which are icterids and, belonging to the superfamily Passeroidea songbirds, are quite unrelated to the true orioles.The orioles are...
s and vireos.
Clarification of the interrelationships of the corvids has been achieved based on cladistic analysis of several DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
s. The jays and magpies do not constitute monophyletic lineages, but rather seem to split up into an American
Americas
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...
and Old World
Old World
The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
lineage, and an Holarctic
Holarctic
The Holarctic ecozone refers to the habitats found throughout the northern continents of the world as a whole. This region is divided into the Palearctic, consisting of Northern Africa and all of Eurasia, with the exception of Southeast Asia and the Indian subcontinent, and the Nearctic,...
and Oriental lineage, respectively. These are not closely related among each other. The position of the Azure-winged Magpie
Azure-winged Magpie
The Azure-winged Magpie is a bird in the crow family. It is 31–35 cm long and similar in overall shape to the European Magpie but is more slender with proportionately smaller legs and bill. It belongs to the monotypical genus Cyanopica.It has a glossy black top to the head and a white throat...
, which has always been a major enigma, is even less clear than before.
FAMILY CORVIDAE
- ChoughChoughThe Red-billed Chough or Chough , Pyrrhocorax pyrrhocorax, is a bird in the crow family; it is one of only two species in the genus Pyrrhocorax...
s- Genus Pyrrhocorax
- Alpine ChoughAlpine ChoughThe Alpine Chough , or Yellow-billed Chough, is a bird in the crow family, one of only two species in the genus Pyrrhocorax. Its two subspecies breed in high mountains from Spain east through southern Europe and North Africa to Central Asia, India and China, and it may nest at a higher altitude...
, Pyrrhocorax graculus - Red-billed ChoughRed-billed ChoughThe Red-billed Chough or Chough , Pyrrhocorax pyrrhocorax, is a bird in the crow family; it is one of only two species in the genus Pyrrhocorax...
, Pyrrhocorax pyrrhocorax
- Alpine Chough
- Genus Pyrrhocorax
- TreepieTreepieThe treepies comprise four closely related genera of long-tailed passerine birds in the family Corvidae...
s- Genus CrypsirinaCrypsirinaCrypsirina is a small genus of long-tailed passerine birds in the crow and jay family Corvidae. The two species are highly arboreal and rarely come to the ground to feed.They are* Black Racket-tailed Treepie, Crypsirina temia...
- Hooded TreepieHooded TreepieThe Hooded Treepie is a species of bird in the Corvidae family.It is endemic to Burma.Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical dry shrubland....
, Crypsirina cucullata - Black Racket-tailed TreepieBlack Racket-tailed TreepieThe Black Racket-tailed Treepie is an Asian treepie, a member of the Corvidae family.It has a velvety-black forehead of short, plush black feathers with the rest of the bird being an oily green colour, though appearing black in dim light...
, Crypsirina temia
- Hooded Treepie
- Genus DendrocittaDendrocittaDendrocitta is a genus of long-tailed passerine birds in the crow and jay family Corvidae. They are resident in tropical South and Southeast Asia....
- Andaman TreepieAndaman TreepieThe Andaman Treepie is a species of bird in the Corvidae family.It is endemic to the Andaman Islands of India.Its natural habitat is subtropical or tropical moist lowland forests.It is threatened by habitat loss....
, Dendrocitta bayleyi - Bornean TreepieBornean TreepieThe Bornean Treepie is a passerine bird belonging to the Dendrocitta genus of treepies in the crow family, Corvidae. It is endemic to the island of Borneo in South-east Asia. It is sometimes treated as a subspecies of the Sumatran Treepie The Bornean Treepie (Dendrocitta cinerascens) is a...
, Dendrocitta cinerascens - Grey TreepieGrey TreepieThe Grey Treepie, also known as the Himalayan Treepie, is an Asian treepie, a medium sized and long-tailed member of the crow family. They are widely distributed along the foothills of the Himalayas in South Asia and extending into Southeast Asia...
, Dendrocitta formosae - Black-faced Treepie (Collared Treepie)Black-faced TreepieThe Black-faced or Black-browed Treepie is an Asian treepie, a small perching bird of the Corvidae family....
, Dendrocitta frontalis - White-bellied TreepieWhite-bellied TreepieThe White-bellied Treepie is a bird of the crow family endemic to the forests of southern India. They overlap in distribution in some areas with the Rufous Treepie but are easily to tell apart both from appearance and call....
, Dendrocitta leucogastra - Sumatran Treepie, Dendrocitta occipitalis
- Rufous TreepieRufous TreepieThe Rufous Treepie is an Asian treepie, a member of the Corvidae family. It is long tailed and has loud musical calls making it very conspicuous. It is found commonly in open scrub, agricultural areas, forests as well as urban gardens...
, Dendrocitta vagabunda
- Andaman Treepie
- Genus Platysmurus
- Black MagpieBlack MagpieThe Black Magpie is a species of bird in the Corvidae family.Despite its name, it is neither a magpie nor, as was long believed, a jay, but a treepie. Treepies are a distinct group of corvids externally similar to magpies. It is monotypic within the genus Platysmurus...
, Platysmurus leucopterus
- Black Magpie
- Genus Temnurus
- Ratchet-tailed TreepieRatchet-tailed TreepieThe Ratchet-tailed Treepie is a species of bird in the Corvidae family. It is monotypic within the genus Temnurus.It is found in Cambodia, China, Laos, Thailand, and Vietnam....
, Temnurus temnurus
- Ratchet-tailed Treepie
- Genus Crypsirina
- Oriental magpieMagpieMagpies are passerine birds of the crow family, Corvidae.In Europe, "magpie" is often used by English speakers as a synonym for the European Magpie, as there are no other magpies in Europe outside Iberia...
s- Genus Cissa
- Green MagpieGreen MagpieThe Green Magpie is a member of the Crow family, roughly about the size of the Eurasian Jay or slightly smaller. It is a vivid green in colour , slightly lighter on the underside and has a thick black stripe from the bill to the nape...
, Cissa chinensis - Yellow-breasted MagpieYellow-breasted MagpieThe Indochinese Green Magpie or Yellow-breasted Magpie is a passerine bird of crow family, Corvidae. It is native to China and south east Asia....
, Cissa hypoleuca - Short-tailed MagpieShort-tailed MagpieThe Short-tailed Green Magpie , also known as the Short-tailed Magpie, is a passerine bird in the crow family, Corvidae. It is endemic to montane forests on the southeast Asian islands of Borneo and Java. It dwells in thick vegetation in the mid and upper storeys of forests, and makes only short...
, Cissa thalassina
- Green Magpie
- Genus UrocissaUrocissaUrocissa is a genus of birds in the family Corvidae, which resides in the huge Passerine order. It consists of mainly brightly coloured magpies in Asia.Species in the genus Urocissa:* Formosan Blue Magpie, Urocissa caerulea...
- Formosan Blue MagpieFormosan Blue MagpieThe Taiwan Blue Magpie , also called the Taiwan Magpie or Formosan Blue Magpie or the "long-tailed mountain lady" , is a member of the Crow family...
, Urocissa caerulea - Red-billed Blue MagpieRed-billed Blue MagpieThe Red-billed Blue Magpie, Urocissa erythrorhyncha is a species of bird in the crow family Corvidae. It is about the same size as the European Magpie but has a much longer tail, the longest tail of any corvid. It is 65-68 cm long and weighs 196-232 grams .-Description:The head, neck and breast...
, Urocissa erythrorhyncha - Gold-billed MagpieGold-billed MagpieThe Yellow-billed Blue Magpie or Gold-billed Magpie is a passerine bird in the crow and jay family, Corvidae. It forms a superspecies with the Taiwan Blue Magpie and the Red-billed Blue Magpie...
, Urocissa flavirostris - Sri Lanka Blue MagpieSri Lanka Blue MagpieThe Sri Lanka Blue Magpie or Ceylon Magpie is a member of the crow family living in the hill forests of Sri Lanka, where it is endemic....
, Urocissa ornata - White-winged MagpieWhite-winged MagpieThe White-winged Magpie is a passerine bird of the crow family, Corvidae. It is unusual among the members of its genus in that it is black and white, lacking the blue plumage other Urocissa magpies have. Thus, it is sometimes placed in its own monotypic genus, Cissopica, though it appears to have...
, Urocissa whiteheadi
- Formosan Blue Magpie
- Genus Cissa
- Old World jayJayThe jays are several species of medium-sized, usually colorful and noisy, passerine birds in the crow family Corvidae. The names jay and magpie are somewhat interchangeable, and the evolutionary relationships are rather complex...
s- Genus GarrulusGarrulusThe genus Garrulus contains the Old World jays, passerine birds of the family Corvidae, and numbers three species.* Eurasian Jay * Lanceolated Jay * Lidth's Jay...
- Eurasian JayEurasian JayThe Eurasian Jay is a species of bird occurring over a vast region from Western Europe and north-west Africa to the Indian Subcontinent and further to the eastern seaboard of Asia and down into south-east Asia...
, Garrulus glandarius - Lanceolated JayLanceolated JayThe Lanceolated Jay or Black-headed Jay is roughly the same size as its close relative the Eurasian Jay, but a little more slender overall except for the bill which is slightly shorter and thicker...
, Garrulus lanceolatus - Lidth's JayLidth's JayThe Lidth's Jay is a passerine bird in the family Corvidae, native to Japan. It is slightly larger than its close relative the Eurasian Jay, with a proportionately stouter bill and also a longer tail...
, Garrulus lidthi
- Eurasian Jay
- Genus Podoces - ground jays
- Biddulph's Ground Jay, Podoces biddulphi
- Henderson's Ground Jay, Podoces hendersoni
- Grey Ground Jay, Podoces panderi
- Persian Ground Jay, Podoces pleskei
- Genus Ptilostomus
- PiapiacPiapiacThe Piapiac is a member of the crow family, and is the only member of the genus Ptilostomus. According to recent findings, it is most closely related to the Central Asian ground jays .-Description:...
, Ptilostomus afer
- Piapiac
- Genus Garrulus
- Stresemann's Bush CrowStresemann's Bush CrowThe Stresemann's Bushcrow , also known as Abyssinian Pie, Bush Crow, Ethiopian Bushcrow, or by its generic name Zavattariornis, is a rather starling-like bird, which is currently thought to be member of the crow family, Corvidae, though this is uncertain...
- Genus Zavattariornis
- Stresemann's Bush CrowStresemann's Bush CrowThe Stresemann's Bushcrow , also known as Abyssinian Pie, Bush Crow, Ethiopian Bushcrow, or by its generic name Zavattariornis, is a rather starling-like bird, which is currently thought to be member of the crow family, Corvidae, though this is uncertain...
, Zavattariornis stresemanni
- Stresemann's Bush Crow
- Genus Zavattariornis
- NutcrackersNutcracker (bird)The nutcrackers are a genus of two species of passerine bird, in the family Corvidae, related to the jays and crows. One, the Spotted Nutcracker , occurs in Europe and Asia, the other, Clark's Nutcracker , in western North America.The most important food resources for both these species are the...
- Genus Nucifraga
- Spotted NutcrackerSpotted NutcrackerThe Spotted Nutcracker, Eurasian Nutcracker, or just Nutcracker, is a passerine bird slightly larger than the Eurasian Jay. It has a much larger bill and a slimmer looking head without any crest. The feathering over its body is predominantly a chocolate brown with distinct white spots and streaks...
, Nucifraga caryocatactes - Clark's NutcrackerClark's NutcrackerClark's Nutcracker , sometimes referred to as Clark's Crow or Woodpecker Crow, is a passerine bird in the family Corvidae. It is slightly smaller than its Eurasian relative the Spotted Nutcracker . It is ashy-grey all over except for the black-and-white wings and central tail feathers...
, Nucifraga columbiana
- Spotted Nutcracker
- Genus Nucifraga
- Holarctic magpieMagpieMagpies are passerine birds of the crow family, Corvidae.In Europe, "magpie" is often used by English speakers as a synonym for the European Magpie, as there are no other magpies in Europe outside Iberia...
s- Genus PicaPica (genus)Pica is the genus of two to four species of birds in the family Corvidae in both the New World and the old. They have long tails and have predominantly black and white markings. One species ranges widely from Europe through Asia, one occurs all over North America and the third is restricted to...
- Black-billed MagpieBlack-billed MagpieThe Black-billed Magpie is a bird in the crow family that inhabits the western half of North America. It is notable for its domed nests, and for being one of only four North American songbirds whose tail makes up half or more of the total body length The Black-billed Magpie (Pica hudsonia) is a...
, Pica hudsonia - Yellow-billed MagpieYellow-billed MagpieThe Yellow-billed Magpie, Pica nuttalli, is a large bird in the crow family found only in California. It inhabits the Central Valley and the adjacent chaparral foothills and mountains...
, Pica nuttalli - European MagpieEuropean MagpieThe European Magpie, Eurasian Magpie, or Common Magpie, , is a resident breeding bird throughout Europe, much of Asia and northwest Africa. It is one of several birds in the crow family named as magpies, and belongs to the Holarctic radiation of "monochrome" magpies...
, Pica pica - Korean MagpieKorean MagpieThe Korean Magpie Pica sericea, known as "ggachee" in Korean, is generally treated as an East Asian subspecies, of the European Magpie , but it may be a distinct species. It is a common symbol of the Korean identity, and has been adopted as the "official bird" of numerous South Korean cities,...
, Pica (pica) sericea
- Black-billed Magpie
- Genus Pica
- True crows (crowCrowCrows form the genus Corvus in the family Corvidae. Ranging in size from the relatively small pigeon-size jackdaws to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents and several...
s, ravenRavenRaven is the common name given to several larger-bodied members of the genus Corvus—but in Europe and North America the Common Raven is normally implied...
s, jackdawJackdawThe Jackdaw , sometimes known as the Eurasian Jackdaw, European Jackdaw or Western Jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa, it is mostly sedentary, although northern and eastern populations migrate south in winter. Four subspecies are...
s and rooksRook (bird)The Rook is a member of the Corvidae family in the passerine order of birds. Named by Carl Linnaeus in 1758, the species name frugilegus is Latin for "food-gathering"....
)- Genus Corvus
- Australian and Melanesian species
- Little Crow, Corvus bennetti
- Australian RavenAustralian RavenThe Australian Raven is the largest Australian member of the genus Corvus and one of three Australian species commonly known as ravens. It is a more slender bird than the Common Raven of the Northern Hemisphere but is otherwise similar...
, Corvus coronoides - Bismarck CrowBismarck CrowThe Bismarck Crow is a species of crow genus found on New Britain and nearby islands. Until 2009, it was considered a subspecies of the Torresian Crow , when it was classified as a species in the May 2009 IOC birdlist....
, Corvus insularis - Brown-headed CrowBrown-headed CrowThe Brown-headed Crow is a species of bird in the Corvidae family.It is endemic to Indonesia.Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical mangrove forests....
, Corvus fuscicapillus - Bougainville CrowBougainville CrowThe Bougainville Crow is a species of bird in the crow family Corvidae.It is found in on the island of Bougainville in Papua New Guinea and the neighbouring Shortland Islands in the Solomon Islands...
, Corvus meeki - Little RavenLittle RavenThe Little Raven is a species of the crow and raven family Corvidae, that is endemic to Australia. It has all-black plumage, beak and legs with a white iris, as do the other Corvus members in Australia and some species from the islands to the north.-Taxonomy:Although the Little Raven was first...
, Corvus mellori - New Caledonian CrowNew Caledonian CrowThe New Caledonian Crow is a tool-using species of crow endemic to New Caledonia and the Loyalty Islands. These crows are some of the only non-primate animals known to invent new tools by modifying existing ones, and then passing these innovations on to other individuals in the cultural group...
, Corvus moneduloides - Torresian CrowTorresian CrowThe Torresian Crow , also occasionally called the Australian Crow or Papuan Crow in those respective countries, is an Australasian member of the crow genus...
, Corvus orru - Forest RavenForest RavenThe Forest Raven is a large species of the crow genus native to south-eastern Australia and Tasmania.-Description:The Forest Raven is 50–52 cm in length with glossy black plumage and a white iris. It has a proportionately larger bill and shorter tail than the other mainland corvid species and...
, Corvus tasmanicus- Relict Raven, Corvus (tasmanicus) boreus
- Grey CrowGrey CrowThe Grey Crow , formerly known as the Bare-faced Crow, is about the same size as the Eurasian Carrion Crow but has somewhat different proportions and quite atypical feather pigmentation during the juvenile phase for a member of this genus.The tail feathers are relatively long and graduated and...
, Corvus tristis - Long-billed CrowLong-billed CrowThe Long-billed Crow, Corvus validus, is a crow that ranges in the Northern Moluccas. It has a long bill and white iris. This crow is large with glossy plumage, and is of Least Concern....
, Corvus validus - White-billed CrowWhite-billed CrowThe White-billed crow is a member of the Crow family found on the Solomon Islands.It is a short and stocky forest bird with a short, squared-off tail and a relatively large head with a very distinctive deep and curved pale ivory-coloured bill with a darker tip...
, Corvus woodfordi
- Pacific island species
- [[ʻAlala|Alalā (Hawaiian Crow)]], Corvus hawaiiensis (formerly Corvus tropicus) (extinct in the wildExtinct in the WildExtinct in the Wild is a conservation status assigned to species or lower taxa, the only known living members of which are being kept in captivity or as a naturalized population outside its historic range.-Examples:...
) - Mariana CrowMariana CrowThe Mariana Crow is a species of the crow family from the north Pacific. It is an endangered species which has steadily declined in numbers since the 1960s.-Description:...
, Corvus kubaryi
- [[ʻAlala|Alalā (Hawaiian Crow)]], Corvus hawaiiensis (formerly Corvus tropicus) (extinct in the wild
- Tropical Asian species
- Daurian JackdawDaurian JackdawThe Daurian Jackdaw is a member of the Corvidae or crow family of birds. It is closely related to the Eurasian Jackdaw. The name derives from the Dauria region of eastern Russia....
, Corvus dauuricus - Slender-billed CrowSlender-billed CrowThe Slender-billed Crow is a species of bird in the Corvidae family. Its eastern populations are called Violaceous Crow and sometimes separated as Corvus violaceus....
, Corvus enca - Flores CrowFlores CrowThe Flores Crow is a species of bird in the Corvidae family.It is endemic to Indonesia.Its natural habitats are subtropical or tropical dry forests and subtropical or tropical moist lowland forests....
, Corvus florensis - Large-billed Crow, Corvus macrorhynchos
- Jungle CrowJungle CrowThe Jungle Crow , is a widespread Asian species of crow. They are very adaptable and are able to survive on a wide range of food sources making them capable of colonizing new areas due to which they are often considered a nuisance, especially on islands...
, Corvus (macrorhynchos) levaillantii
- Jungle Crow
- House CrowHouse Crowthumb|300px|Bangalore, IndiaThe House Crow , also known as the Colombo Crow is a common bird of the Crow family that is of Asian origin but now found in many parts of the world, where they arrived assisted by shipping. It is between the Jackdaw and the Carrion Crow in size but is relatively...
, Corvus splendens - Collared CrowCollared CrowThe Collared Crow , also known as the Ring-necked Crow or White-collared Crow, is a member of the Corvidae family native to China.-Description:...
, Corvus torquatus - Piping CrowPiping CrowThe Piping Crow is a species of bird in the Corvidae family. It is endemic to Indonesia.Its natural habitat is subtropical or tropical moist lowland forests.-References:...
, Corvus typicus - Banggai CrowBanggai CrowThe Banggai Crow, Corvus unicolor, is a member of the crow family from Banggai in Indonesia. It is listed as critically endangered by IUCN and was even feared extinct, but was finally rediscovered during surveys on Peleng Island by Indonesian ornithologist Mochamad Indrawan in 2007 and 2008.It was...
, Corvus unicolor
- Daurian Jackdaw
- Eurasian and North African species
- Hooded CrowHooded CrowThe Hooded Crow is a Eurasian bird species in the crow genus. Widely distributed, it is also known locally as Scotch Crow, Danish Crow, and Corbie or Grey Crow in Ireland, which is what its Welsh name, Brân Lwyd, translates as...
, Corvus cornix- Mesopotamian CrowMesopotamian CrowThe Mesopotamian Crow , also known as the Iraq Pied Crow, is a bird species of the crow genus. The crow is native to the region of Mesopotamia, in southern Iraq and southwest Iran, between the Tigris and Euphrates rivers....
, Corvus (cornix) capellanus
- Mesopotamian Crow
- Carrion Crow (Western Carrion Crow)Carrion CrowThe Carrion Crow is a member of the passerine order of birds and the crow family which is native to western Europe and eastern Asia.-Taxonomy:...
, Corvus corone- Eastern Carrion Crow, Corvus (corone) orientalis
- RookRook (bird)The Rook is a member of the Corvidae family in the passerine order of birds. Named by Carl Linnaeus in 1758, the species name frugilegus is Latin for "food-gathering"....
, Corvus frugilegus - JackdawJackdawThe Jackdaw , sometimes known as the Eurasian Jackdaw, European Jackdaw or Western Jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa, it is mostly sedentary, although northern and eastern populations migrate south in winter. Four subspecies are...
, Corvus monedula - Fan-tailed RavenFan-tailed RavenThe Fan-tailed Raven is a passerine bird of the crow family native to Eastern Africa and the Arabian Peninsula. Like the Chihuahuan Raven it is one of the smaller species , in fact it is about the same size as a Carrion Crow but with a much thicker bill, shorter tail and much larger...
, Corvus rhipidurus - Brown-necked RavenBrown-necked RavenThe 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...
, Corvus ruficollis
- Hooded Crow
- Holarctic species
- Common RavenCommon RavenThe Common Raven , also known as the Northern Raven, is a large, all-black passerine bird. Found across the northern hemisphere, it is the most widely distributed of all corvids...
, Corvus corax (see also next section)- Pied RavenPied RavenThe Pied Raven was a colour morph of the North Atlantic subspecies of the Common Raven which was only found on the Faroe Islands and has disappeared since the mid twentieth century. It had large areas of white feathering, most frequently on the head, the wings and the belly, and its beak was light...
, Corvus corax varius morpha leucophaeus (an extinct color variant)
- Pied Raven
- Common Raven
- North and Central American species
- American CrowAmerican CrowThe American Crow is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America...
, Corvus brachyrhynchos - Northwestern CrowNorthwestern CrowThe Northwestern Crow is an all-black passerine bird of the crow genus native to the northwest of North America. It is very similar to the more western forms of the widespread American Crow , but it averages slightly smaller with proportionately smaller feet and a slightly more slender bill...
, Corvus caurinus - Chihuahuan RavenChihuahuan RavenThe Chihuahuan Raven , is a species of bird in the family Corvidae that is native to the United States and Mexico. It was formerly known as the American White-necked Raven, and has the proportions of a Common Raven with a heavy bill, but is about the same size as a Carrion Crow, or slightly larger...
, Corvus cryptoleucus - Tamaulipas CrowTamaulipas CrowThe Tamaulipas Crow a crow found in northeastern Mexico and some of southern Texas.- Description :It is a relatively small and sleek looking crow, in length. It has very glossy dark, bluish plumage, which appears soft and silky. The bill is quite slender and black, as are the legs and feet...
, Corvus imparatus - Jamaican CrowJamaican CrowThe Jamaican Crow, Corvus jamaicensis is a comparatively small crow species . It shares several key morphological features with two further West Indian species, the Cuban Crow, Corvus nasicus and the White-necked Crow, Corvus leucognaphalus of Hispaniola which are almost certainly very closely...
, Corvus jamaicensis - White-necked CrowWhite-necked CrowThe White-necked Crow is the largest of the four Caribbean crow species. Two other species, the Cuban Crow and the Jamaican Crow , appear to be very closely related to it sharing several key morphological features...
, Corvus leucognaphalus - Cuban CrowCuban CrowThe Cuban Crow is one of four species of crow that occur on a few key islands in the Caribbean. It is closely related to the White-necked Crow and Jamaican Crow , with which it shares similar features. The fourth Caribbean crow, the Palm Crow The Cuban Crow (Corvus nasicus) is one of four species...
, Corvus nasicus - Fish CrowFish CrowThe Fish Crow is a species of crow that is associated with wetland habitats in the eastern and southeastern United States.-Taxonomy:The Fish Crow was first described by Alexander Wilson in 1812...
, Corvus ossifragus - Palm CrowPalm CrowThe Palm Crow is a relatively small black bird in the crow family that occurs mostly on the large Caribbean island of Hispaniola, itself divided into the two countries of Dominican Republic and Haiti. It was formerly quite frequent on Cuba but has become severely reduced in number and may be...
, Corvus palmarum - Sinaloan CrowSinaloan CrowThe Sinaloa Crow is a crow native to western Mexico. Visually, it is nearly identical to and the same length as the Tamaulipas Crow . It has the same purple-glossed, silky, black plumage with a black bill, legs, and feet...
, Corvus sinaloae - Western Raven, Corvus (corax) sinuatus
- American Crow
- Tropical African species
- White-necked RavenWhite-necked RavenThe White-necked Raven, Corvus albicollis, is somewhat smaller than the Common Raven or indeed its nearest relative, the Thick-billed Raven C. crassirostris.-Description:...
, Corvus albicollis - Pied CrowPied CrowThe Pied Crow is a widely distributed African bird species in the crow genus.Structurally, the Pied Crow is better thought of as a small crow-sized Raven, especially as it can hybridise with the Somali Crow where their ranges meet in the Horn of Africa...
, Corvus albus - Cape CrowCape CrowThe Cape Crow or Black Crow is slightly larger than the Carrion Crow and is completely black with a slight gloss of purple in the feathers. It has proportionately longer legs, wings and tail too and has a much longer, slimmer bill that seems to be designed for probing into the ground for...
, Corvus capensis - Thick-billed RavenThick-billed RavenThe Thick-billed Raven , a Corvid from the Horn of Africa, shares with the Common Raven the distinction of being the largest in the Corvid family, and indeed the largest of the bird order Passeriformes . They measure 60-64 cm in length and weigh 1.5 kg...
, Corvus crassirostris - Somali Crow (Dwarf Raven)Somali CrowThe Somali Crow or Dwarf Raven, Corvus edithae is approximately the size of the Carrion Crow, Corvus corone but with longer bill and somewhat more brownish cast to the feathers especially when worn....
, Corvus edithae
- White-necked Raven
- Australian and Melanesian species
- Genus Corvus
- Azure-winged MagpieAzure-winged MagpieThe Azure-winged Magpie is a bird in the crow family. It is 31–35 cm long and similar in overall shape to the European Magpie but is more slender with proportionately smaller legs and bill. It belongs to the monotypical genus Cyanopica.It has a glossy black top to the head and a white throat...
- Genus Cyanopica
- Azure-winged MagpieAzure-winged MagpieThe Azure-winged Magpie is a bird in the crow family. It is 31–35 cm long and similar in overall shape to the European Magpie but is more slender with proportionately smaller legs and bill. It belongs to the monotypical genus Cyanopica.It has a glossy black top to the head and a white throat...
, Cyanopica cyana
- Azure-winged Magpie
- Genus Cyanopica
- Grey jayJayThe jays are several species of medium-sized, usually colorful and noisy, passerine birds in the crow family Corvidae. The names jay and magpie are somewhat interchangeable, and the evolutionary relationships are rather complex...
s- Genus PerisoreusPerisoreusThe genus Perisoreus is a very small genus of Jays from the Boreal regions of North America and Eurasia from Scandinavia to the Asian seaboard. An isolated species also occurs in north-western Szechuan province of China...
- Gray Jay (Canada Jay, Whiskeyjack)Gray JayThe Gray Jay , also Grey Jay, Canada Jay, or Whiskey Jack, is a member of the crow and jay family found in the boreal forests across North America north to the tree-line and in subalpine forests of the Rocky Mountains south to New Mexico and Arizona...
, Perisoreus canadensis - Siberian JaySiberian JayThe Siberian Jay Perisoreus infaustus, is a jay found in north Eurasia. The species has a wide range and a large global population . It is one of three members of the genus Perisoreus, the others being the Sichuan Jay, P...
, Perisoreus infaustus - Sichuan JaySichuan JayThe Sichuan Jay is a species of bird in the Corvidae family. It is endemic to China. It is one of three members of the genus Perisoreus, the others being the Siberian Jay, P. infaustus, found from Norway to eastern Russia and the Gray Jay, P. canadensis, restricted to the boreal forest and...
, Perisoreus internigrans
- Gray Jay (Canada Jay, Whiskeyjack)
- Genus Perisoreus
- New World jayJayThe jays are several species of medium-sized, usually colorful and noisy, passerine birds in the crow family Corvidae. The names jay and magpie are somewhat interchangeable, and the evolutionary relationships are rather complex...
s- Genus AphelocomaAphelocomaThe passerine birds of the genus Aphelocomainclude the scrub-jays and relatives. They are New World jays found in Mexico, western Central America and the western United States, with an outlying population in Florida...
- scrub-jays- Western Scrub JayWestern Scrub JayThe Western Scrub-Jay , is a species of scrub-jay native to western North America. It ranges from southern Washington to central Texas and central Mexico. It comprises three distinct subspecies groups, all of which may be separate species...
, Aphelocoma californica - Florida Scrub JayFlorida Scrub JayThe Florida Scrub-Jay is one of the species of scrub-jay native to North America. It is the only species of bird endemic to the U.S. state of Florida. Because of this, it is heavily sought by birders who travel from across the country to observe this unique species...
, Aphelocoma coerulescens - Island Scrub JayIsland Scrub JayThe Island Scrub-Jay or Island Jay is one of the species of Aphelocoma native to North America and is endemic to Santa Cruz Island off the coast of Southern California...
, Aphelocoma insularis - Mexican JayMexican JayThe Mexican Jay, Aphelocoma wollweberi, formerly known as the Gray-breasted Jay, is a New World jay native to the Sierra Madre Oriental, Sierra Madre Occidental, and Central Plateau of Mexico. It reaches north to eastern Arizona, western New Mexico and western Texas in the United States...
, Aphelocoma wollweberi - Transvolcanic JayTransvolcanic JayThe Transvolcanic Jay is a medium-large passerine similar in size to most other jays, with a blue head, blue-gray mantle, blue wings and tail, gray breast and underparts. The sexes are morphologically similar, and juveniles differ only in having less blue coloration. The iris is brown and legs...
, Aphelocoma ultramarina - Unicolored JayUnicolored JayThe Unicolored Jay is an Aphelocoma jay native to cloud forests of northwestern Central America and southern and southeastern Mexico, from central Honduras west to central Guerrero, southern Veracruz and extreme southern San Luis Potosi...
, Aphelocoma unicolor
- Western Scrub Jay
- Genus CalocittaCalocittaThe magpie-jays are a genus, Calocitta, of the family Corvidae native to the southern part of North America. The two known species are known to form hybrids.- Species :* Black-throated Magpie-Jay, Calocitta colliei...
- magpie-jays- Black-throated Magpie-JayBlack-throated Magpie-jayThe Black-throated Magpie-Jay is a strikingly long-tailed jay of northwestern Mexico.-Description:This species is 58.5 to 76.5 cm long, more than half of which is the tail, and weight is 225-251 grams...
, Calocitta colliei - White-throated Magpie-JayWhite-throated Magpie-jayThe White-throated Magpie-Jay, Calocitta formosa, is a large Central American jay species. It ranges in Pacific-slope thornforest from Jalisco, Mexico to Guanacaste, Costa Rica. Magpie-jays are noisy, gregarious birds, often traveling in easy-to-find flocks, mobbing their...
, Calocitta formosa
- Black-throated Magpie-Jay
- Genus CyanocittaCyanocittaThe genus Cyanocitta is a New World genus of jays, passerine birds of the family Corvidae. Cyanocitta includes only two of the New World jays; they are blue, crested birds that differ in the colour of the head. Their ranges generally do not overlap....
- Blue JayBlue JayThe Blue Jay is a passerine bird in the family Corvidae, native to North America. It is resident through most of eastern and central United States and southern Canada, although western populations may be migratory. It breeds in both deciduous and coniferous forests, and is common near and in...
, Cyanocitta cristata - Steller's JaySteller's JayThe Steller's Jay is a jay native to western North America, closely related to the Blue Jay found in the rest of the continent, but with a black head and upper body. It is also known as the Long-crested Jay, Mountain Jay, and Pine Jay...
, Cyanocitta stelleri
- Blue Jay
- Genus CyanocoraxCyanocoraxCyanocorax is a genus of New World jays, passerine birds in the crow family, Corvidae. The generic name is derived from the Greek words κυανος , meaning "dark blue," and κοραξ , meaning "raven"....
- Black-chested JayBlack-chested JayThe Black-chested Jay is a species of bird in the Corvidae family.It is found in Colombia, Costa Rica, Panama, and Venezuela....
, Cyanocorax affinis - Purplish-backed JayPurplish-backed JayThe Purplish-backed Jay, Cyanocorax beecheii, is a bird of the crow family Corvidae, with purple feathers on its back and black feathers everywhere else. It is endemic to Mexico.-External links:* on the Internet Bird Collection...
, Cyanocorax beecheii - Azure JayAzure JayThe Azure Jay is a passeriform bird of the crow family Corvidae. It is found in the Atlantic Forest, especially with Araucaria angustifolia, in south-eastern Brazil , far eastern Paraguay and far north-eastern Argentina...
, Cyanocorax caeruleus - Cayenne JayCayenne JayThe Cayenne Jay is a species of bird in the Corvidae family.It is found in Brazil, French Guiana, Guyana, Suriname, and Venezuela....
, Cyanocorax cayanus - Plush-crested JayPlush-crested JayThe Plush-crested Jay is a jay of the Corvidae family, which includes the crows and their many allies. It is found in central-southern South America in southwestern Brazil, Bolivia, Paraguay, Uruguay, and northeastern Argentina, including southern regions of the Amazon Basin river systems,...
, Cyanocorax chrysops - Curl-crested JayCurl-crested JayThe Curl-crested Jay is a jay from South America.This New World or "blue" jay is a beautiful and large bird with predominantly dark blue back, an almost black head and neck, and snow-white chest and underparts...
, Cyanocorax cristatellus - Purplish JayPurplish JayThe Purplish Jay is a species of bird in the Corvidae family.It is found in Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay....
, Cyanocorax cyanomelas - White-naped JayWhite-naped JayThe White-naped Jay is a species of bird in the Corvidae family.It is endemic to Brazil - where it's known as the Gralha Cancã or the Cancão ....
, Cyanocorax cyanopogon - Tufted JayTufted JayThe Tufted Jay is a species of bird in the Corvidae family. It is endemic to a small area of the Sierra Madre Occidental of Sinaloa and Durango in Mexico....
, Cyanocorax dickeyi - Azure-naped JayAzure-naped JayThe Azure-naped Jay is a species of bird in the Corvidae family.It is found in Brazil, Colombia, and Venezuela.Its natural habitats are subtropical or tropical moist lowland forests and subtropical or tropical dry shrubland....
, Cyanocorax heilprini - Bushy-crested JayBushy-crested JayThe Bushy-crested Jay is a species of bird in the Corvidae family. It is found in El Salvador, Guatemala, Honduras, and Nicaragua. Its natural habitats are subtropical or tropical moist montanes and heavily degraded former forest.-References:* BirdLife International 2004. . Downloaded on 25...
, Cyanocorax melanocyaneus - Brown JayBrown JayThe Brown Jay is a large American Jay which has the habitus of a magpie, but is slightly smaller and with a shorter tail, though the bill is larger.It occurs from Mexico south into Central America on the Gulf slope...
, Cyanocorax morio - White-tailed JayWhite-tailed JayThe White-tailed Jay is a species of bird in the Corvidae family.It is found in Ecuador and Peru.Its natural habitats are subtropical or tropical dry forests and subtropical or tropical moist lowland forests.-References:...
, Cyanocorax mystacalis - San Blas JaySan Blas JayThe San Blas Jay is a species of bird in the Corvidae family.It is endemic to Mexico.Its natural habitat is subtropical or tropical dry forests.-References:...
, Cyanocorax sanblasianus - Violaceous JayViolaceous JayThe Violaceous Jay is a species of bird in the Corvidae family, the crows and their allies.It is found in Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela. Its natural habitats are subtropical or tropical moist lowland forests and heavily degraded former forest...
, Cyanocorax violaceus - Green JayGreen JayThe Green Jay is a bird species of the New World jays, which exhibits distinct regional variations within its large but discontinuous range...
, Cyanocorax ynca - Yucatan JayYucatan JayThe Yucatán Jay is a species of bird in the Corvidae family, the crows and their allies.It is found in Belize, Guatemala, and southern Mexico....
, Cyanocorax yucatanicus
- Black-chested Jay
- Genus CyanolycaCyanolycaCyanolyca is a genus of small jays found in humid highland forests in southern Mexico, Central America and the Andes in South America. All are largely blue and have a black mask. They also possess black bills and legs and are skulking birds...
- Silvery-throated JaySilvery-throated JayThe Silvery-throated Jay is a species of bird in the Corvidae family.It is found in Costa Rica and Panama.Its natural habitat is subtropical or tropical moist montanes.-References:...
, Cyanolyca argentigula - Black-collared JayBlack-collared JayThe Black-collared Jay is a jay found in Andean forests in Ecuador, Colombia and Venezuela. It was formerly considered conspecific with the White-collared Jay....
, Cyanolyca armillata - Azure-hooded JayAzure-hooded JayThe Azure-hooded Jay, Cyanolyca cucullata, is a species of bird in the Corvidae family. It is found in Middle America. Its natural habitat is subtropical or tropical moist montane forest. This species is known to have four subspecies. It is in length and is dark blue with a black head and upper...
, Cyanolyca cucullata - White-throated JayWhite-throated JayThe White-throated Jay is a species of bird in the Corvidae family.It is endemic to Mexico.Its natural habitat is subtropical or tropical moist montanes.It is threatened by habitat loss.- Identification :...
, Cyanolyca mirabilis - Dwarf JayDwarf JayThe Dwarf Jay is a species of bird in the Corvidae family.It is endemic to Mexico.Its natural habitat is subtropical or tropical moist montanes.It is threatened by habitat loss.-References:...
, Cyanolyca nana - Beautiful JayBeautiful JayThe Beautiful Jay is a species of bird in the Corvidae family. It is found in Colombia and Ecuador.Its natural habitat is subtropical or tropical moist montane forests. It is becoming rare due to habitat loss.-References:...
, Cyanolyca pulchra - Black-throated JayBlack-throated JayThe Black-throated Jay is a species of bird in the Corvidae family.It is found in El Salvador, Guatemala, Honduras, and Mexico.Its natural habitat is subtropical or tropical moist montanes.-References:...
, Cyanolyca pumilo - Turquoise JayTurquoise JayThe Turquoise Jay is a species of bird in the Corvidae family.The Turquoise Jay is a vibrant blue jay with a black face mask and collar. It is found exclusively in South America throughout southern Colombia, Ecuador, and northern Peru...
, Cyanolyca turcosa - White-collared JayWhite-collared JayThe White-collared Jay is a species of bird in the Corvidae family. It is found in Andean forests in Peru and Bolivia. It was formerly considered conspecific with the Black-collared Jay.-References:...
, Cyanolyca viridicyana
- Silvery-throated Jay
- Genus Gymnorhinus
- Pinyon JayPinyon JayThe Pinyon Jay is a jay between the North American Blue Jay and the Eurasian Jay in size. It is the only member of the genus Gymnorhinus, . Its overall proportions are very Nutcracker-like and indeed this can be seen as convergent evolution as both birds fill similar ecological niches...
, Gymnorhinus cyanocephalus
- Pinyon Jay
- Genus Aphelocoma
The Crested Jay
Crested Jay
The Crested Jay is a species of bird in the Corvidae family. It is monotypic within the genus Platylophus.It is found in Brunei, Indonesia, Malaysia, Myanmar, and Thailand....
(Platylophus galericulatus) is traditionally included in the Corvidae, but might not be a true member of this family, possibly being closer to the helmet-shrikes
Prionops
The typical helmetshrikes, Prionops, form a bird genus in the helmetshrike family Prionopidae. They were for long usually included in the Malaconotidae.They contains the following species:* Yellow-crested Helmet-shrike...
(Malaconotidae) or shrike
Shrike
Shrikes are passerine birds of the family Laniidae. The family is composed of thirty-one species in three genera. The family name, and that of the largest genus, Lanius, is derived from the Latin word for "butcher", and some shrikes were also known as "butcher birds" because of their feeding habits...
s (Laniidae); it is best considered Corvidae incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
for the time being. Likewise, the Hume's Ground "Jay"
Hume's Ground Tit
The Tibetan Ground-tit or Hume's Ground-tit is a lark-like bird which lives to the north of the Himalayas. It is also known simply as Ground Tit or simply as Hume's Groundpecker. It was formerly thought to belong to the family Corvidae which includes the crows and jays and was called as the Hume's...
(Pseudopodoces humilis) is in fact a member of the tit family Paridae.
Fossil record
The earliest corvid fossilFossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s date to the mid-Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
, about 17 million years ago; Miocorvus and Miopica may be ancestral to crows and some of the magpie lineage, respectively, or similar to the living forms due to convergent evolution
Convergent evolution
Convergent evolution describes the acquisition of the same biological trait in unrelated lineages.The wing is a classic example of convergent evolution in action. Although their last common ancestor did not have wings, both birds and bats do, and are capable of powered flight. The wings are...
. The known prehistoric corvid genera appear to be mainly of the New World and Old World jay and Holarctic magpie lineages:
- Miocorvus (Middle Miocene of Sansan, France)
- Miopica (Middle Miocene of SW Ukraine)
- Miocitta (Pawnee Creek Late Miocene of Logan County, USA)
- Corvidae gen. et sp. indet. (Edson Early Pliocene of Sherman County, USA)
- Protocitta (Early Pleistocene of Reddick, USA)
- Corvidae gen. et sp. indet. (Early/Middle Pleistocene of Sicily) - probably belongs in an extant genus
- Henocitta (Arredondo Clay Middle Pleistocene of Williston, USA)
In addition, there are numerous fossil species of extant genera since the Mio
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
–Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
, mainly European Corvus.
Morphology
Corvids are large to very large passerinePasserine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
s with a robust build, strong legs and all species except the Pinyon Jay
Pinyon Jay
The Pinyon Jay is a jay between the North American Blue Jay and the Eurasian Jay in size. It is the only member of the genus Gymnorhinus, . Its overall proportions are very Nutcracker-like and indeed this can be seen as convergent evolution as both birds fill similar ecological niches...
have nostril
Nostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s covered by bristle-like feathers. Many corvids of temperate zones have mainly black or blue coloured plumage
Plumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
; however, some are pied black and white, some have a blue-purple iridescence and many tropical species are brightly coloured. The sexes are very similar in color and size. Corvids have strong, stout bills and large wingspans. The family includes the largest members of the passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
order.
The smallest corvid is the Dwarf Jay
Dwarf Jay
The Dwarf Jay is a species of bird in the Corvidae family.It is endemic to Mexico.Its natural habitat is subtropical or tropical moist montanes.It is threatened by habitat loss.-References:...
(Aphelocoma nana), at 40 g (1.4 oz) and 21.5 cm (8.5 inches). The largest corvids are the Common Raven
Common Raven
The Common Raven , also known as the Northern Raven, is a large, all-black passerine bird. Found across the northern hemisphere, it is the most widely distributed of all corvids...
(Corvus corax) and the Thick-billed Raven
Thick-billed Raven
The Thick-billed Raven , a Corvid from the Horn of Africa, shares with the Common Raven the distinction of being the largest in the Corvid family, and indeed the largest of the bird order Passeriformes . They measure 60-64 cm in length and weigh 1.5 kg...
(Corvus crassirostris), both of which regularly exceed 1400 grams (3 lbs) and 65 cm (26 inches).
Species can be identified based on size, shape, and geography; however, some, especially the Australian crows, are best identified by their raucous calls.
Ecology
Corvids occur in most climatic zones. Most are sedentary and do not migrateBird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
significantly. However, during a shortage of food, eruptive migration can occur. When species are migratory, they will form large flocks in the fall (around August in the northern hemisphere
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
) and travel south.
One reason for the success of crows, compared to ravens, is their ability to overlap breeding territory. During breeding season, crows were shown to overlap breeding territory six times as much as ravens. This invasion of breeding ranges allowed a related increase in local population density.
Food and feeding
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s, nestlings, small mammals, berries, fruits, seeds, and carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
. However, some corvids, especially the crows, have adapted well to human conditions and have come to rely on anthropogenic foods. In a US study of American Crow
American Crow
The American Crow is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America...
s, Common Raven
Common Raven
The Common Raven , also known as the Northern Raven, is a large, all-black passerine bird. Found across the northern hemisphere, it is the most widely distributed of all corvids...
s and Steller's Jay
Steller's Jay
The Steller's Jay is a jay native to western North America, closely related to the Blue Jay found in the rest of the continent, but with a black head and upper body. It is also known as the Long-crested Jay, Mountain Jay, and Pine Jay...
s around campgrounds and human settlements, the crows appeared to have the most diverse diet of all, taking anthropogenic foods such as bread, spaghetti, fried potatoes, dog food, sandwiches, and livestock feed. The increase in available anthropogenic food sources is contributing to population increase in some corvid species.
Some corvids are predators of other birds. During the wintering months, corvids typically form foraging flocks. However, some crows also eat many agricultural pests including cutworms, wireworms, grasshoppers, and harmful weeds Some corvids will eat carrion, and since they lack a specialized beak for tearing into flesh, they must wait until animals are opened, whether by other predators or as roadkill.
Since crows do not seem to mind human development, it was suggested that the crow population increase would cause increased rates of nest predation. However, Steller's Jays, which are successful independently of human development, are more efficient in plundering small birds' nests than American Crow
American Crow
The American Crow is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America...
s and Common Raven
Common Raven
The Common Raven , also known as the Northern Raven, is a large, all-black passerine bird. Found across the northern hemisphere, it is the most widely distributed of all corvids...
s. Therefore, the human relationship with crows and ravens did not significantly increase nest predation, compared to other factors such as habitat destruction
Habitat destruction
Habitat destruction is the process in which natural habitat is rendered functionally unable to support the species present. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity mainly for the purpose of...
.
Reproduction
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
, protecting territories throughout the year or simply during the breeding season. In some cases territories may only be guarded during the day, with the pair joining off-territory roosts at night. Some corvids are well known communal roosters. Some groups of roosting corvids can be very large, with a roost of 65,000 Rooks
Rook (bird)
The Rook is a member of the Corvidae family in the passerine order of birds. Named by Carl Linnaeus in 1758, the species name frugilegus is Latin for "food-gathering"....
counted in Scotland. Some, including the Rook and the Jackdaw
Jackdaw
The Jackdaw , sometimes known as the Eurasian Jackdaw, European Jackdaw or Western Jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa, it is mostly sedentary, although northern and eastern populations migrate south in winter. Four subspecies are...
, are also communal nesters.
The partner bond in corvids is extremely strong and even lifelong in some species. This monogamous lifestyle, however, can still contain extra-pair copulations. Males and females build large nests together in trees or on ledges. The male will also feed the female during incubation. The nests are constructed of a mass of bulky twigs lined with grass and bark. Corvids can lay between 3 and 10 eggs, typically ranging between 4 and 7. The eggs are usually greenish in colour with brown blotches. Once hatched, the young remain in the nests for up to 6–10 weeks depending on the species. Corvids provide biparental care.
Jackdaws can breed in buildings or in rabbit warrens. White-throated Magpie-jay
White-throated Magpie-jay
The White-throated Magpie-Jay, Calocitta formosa, is a large Central American jay species. It ranges in Pacific-slope thornforest from Jalisco, Mexico to Guanacaste, Costa Rica. Magpie-jays are noisy, gregarious birds, often traveling in easy-to-find flocks, mobbing their...
s are cooperatively breeding corvids where the helpers are mostly female. Cooperative breeding
Cooperative breeding
Cooperative breeding is a social system in which individuals contribute care to offspring that are not their own at the expense of their own reproduction . When reproduction is monopolized by one or few of the adult group members and most adults do not reproduce, but help rear the breeder’s...
takes place when additional adults help raise the nestlings. Such helpers at the nest
Helpers at the nest
Helpers at the nest is a term used in behavioural ecology and evolutionary biology to describe a social structure in which juveniles and sexually mature adolescents of either one or both sexes, remain in association with their parents and help them raise subsequent broods or litters, instead of...
in most cooperatively breeding birds are males, while females join other groups.
Social life
Some corvids have strong organization and community groups. Jackdaws, for example, have a strong social hierarchy, and are facultatively colonial during breeding. Providing mutual aid has also been recorded within many of the corvid species.Young corvids have been known to play and take part in elaborate social game
Game
A game is structured playing, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements...
s. Documented group games follow a "king of the mountain"- and "follow the leader"-type pattern. Other play
Play (activity)
Play is a term employed in ethology and psychology to describe to a range of voluntary, intrinsically motivated activities normally associated with pleasure and enjoyment...
involves the manipulation, passing, and balancing of sticks. Corvids also take part in other activities, such as sliding down smooth surfaces. These games are understood to play a large role in the adaptive and survival ability of the birds.
Mate selection is quite complex and accompanied with much social play in the Corvidae. Youngsters of social corvid species undergo a series of tests, including aerobatic feats, before being accepted as a mate by the opposite sex.
Some corvids can be aggressive. Blue Jay
Blue Jay
The Blue Jay is a passerine bird in the family Corvidae, native to North America. It is resident through most of eastern and central United States and southern Canada, although western populations may be migratory. It breeds in both deciduous and coniferous forests, and is common near and in...
s, for example, are well known to attack anything that threatens their nest. Crows have been known to attack dogs, cats, ravens, and birds of prey. Most of the time these assaults take place as a distraction long enough to allow an opportunity for stealing food.
Intelligence
The brain-to-body weight ratios of corvid brains are among the largest in birds, equal to that of great apes and cetaceans, and only slightly lower than a human. Their intelligence is boosted by the long growing period of the young. By remaining with the parents, the young have more opportunities to learn necessary skills. Since most corvids are cooperative brooders, their young can learn from different members of the group.When compared to dogs and cats in an experiment testing the ability to seek out food according to three-dimensional clues, corvids out-performed the mammals. A metaanalysis testing how often birds invented new ways to acquire food in the wild found corvids the most innovative birds. A 2004 review suggests that their cognitive abilities are on par with those of great apes. Despite structural differences, the brains of corvids and great apes both evolved the ability to make geometrical measurements.
Corvid ingenuity is represented through their feeding skills, memorization abilities, use of tools, and group behaviour. Living in large social groups has long been connected with high cognitive ability. To live in a large group, a member must be able to recognize individuals and track the social position and foraging of other members over time. Members must also be able to distinguish between sex, age, reproductive status, and dominance, and to update this information constantly. It might be that social complexity corresponds to their high cognition.
The European Magpie
European Magpie
The European Magpie, Eurasian Magpie, or Common Magpie, , is a resident breeding bird throughout Europe, much of Asia and northwest Africa. It is one of several birds in the crow family named as magpies, and belongs to the Holarctic radiation of "monochrome" magpies...
is one of the few non-mammal species known to be able to recognize itself in a mirror test
Mirror test
The mirror test is a measure of self-awareness, as animals either possess or lack the ability to recognize themselves in a mirror.The test was developed by Gordon Gallup Jr. in 1970, based in part on observations made by Charles Darwin. While visiting a zoo, Darwin held a mirror up to an orangutan...
.
There are also specific examples of corvid cleverness. One Carrion Crow
Carrion Crow
The Carrion Crow is a member of the passerine order of birds and the crow family which is native to western Europe and eastern Asia.-Taxonomy:...
was documented to crack nuts by placing them on a crosswalk, letting the passing cars crack the shell, waiting for the light to turn red, and then safely retrieving the contents. A group of crows in England took turns lifting garbage bin lids while their companions collected food.
Members of the corvid family have been known to watch other birds, remember where they hide their food, then return once the owner leaves. Corvids also move their food around between hiding places to avoid thievery, but only if they have previously been thieves themselves i.e., they remember previous relevant social contexts, use their own experience of having been a thief to predict the behavior of a pilferer, and can determine the safest course to protect their caches from being pilfered. Studies to assess similar cognitive abilities in apes have been inconclusive.
The ability to hide food requires highly accurate spatial memories. Corvids have been recorded to recall their food's hiding place up to nine months later. It is suggested that vertical landmarks (like trees) are used to remember locations. There has also been evidence that Western Scrub-Jays, which store perishable foods, not only remember where they stored their food, but for how long. This has been compared to episodic memory, previously thought unique to humans.
New Caledonian Crow
New Caledonian Crow
The New Caledonian Crow is a tool-using species of crow endemic to New Caledonia and the Loyalty Islands. These crows are some of the only non-primate animals known to invent new tools by modifying existing ones, and then passing these innovations on to other individuals in the cultural group...
s (Corvus moneduloides) are notable for their highly developed tool fabrication. They make angling tools of twigs and leaves trimmed into hooks, then use the hooks to pull insect larvae from tree holes. Tools are engineered according to task and apparently also to learned preference. Recent studies revealed abilities to solve complicated problems, which suggests high level of innovation of a complex nature. Other corvids that have been observed using tools include the American Crow
American Crow
The American Crow is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America...
, Blue Jay
Blue Jay
The Blue Jay is a passerine bird in the family Corvidae, native to North America. It is resident through most of eastern and central United States and southern Canada, although western populations may be migratory. It breeds in both deciduous and coniferous forests, and is common near and in...
and Green Jay
Green Jay
The Green Jay is a bird species of the New World jays, which exhibits distinct regional variations within its large but discontinuous range...
. Diversity in tool design among corvids suggests cultural variation. Again, great apes are the only other animals known to use tools in such a fashion.
Clark's Nutcracker
Clark's Nutcracker
Clark's Nutcracker , sometimes referred to as Clark's Crow or Woodpecker Crow, is a passerine bird in the family Corvidae. It is slightly smaller than its Eurasian relative the Spotted Nutcracker . It is ashy-grey all over except for the black-and-white wings and central tail feathers...
s and Jackdaw
Jackdaw
The Jackdaw , sometimes known as the Eurasian Jackdaw, European Jackdaw or Western Jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa, it is mostly sedentary, although northern and eastern populations migrate south in winter. Four subspecies are...
s were compared in a 2002 study based on geometric rule learning. The corvids, along with a domestic pigeon
Domestic Pigeon
The Domestic Pigeon was derived from the Rock Pigeon. The Rock Pigeon is the world's oldest domesticated bird. Mesopotamian cuneiform tablets mention the domestication of pigeons more than 5,000 years ago, as do Egyptian hieroglyphics.Research suggests that domestication of pigeons was as early as...
, had to locate a target between two landmarks, while distances and landmarks were altered. The nutcrackers were more accurate in their searches than the jackdaws and pigeons.
The scarecrow
Scarecrow
A scarecrow is, essentially, a decoy, though traditionally, a human figure dressed in old clothes and placed in fields by farmers to discourage birds such as crows or sparrows from disturbing and feeding on recently cast seed and growing crops.-History:In Kojiki, the oldest surviving book in Japan...
is an archetypal scare tactic in the agricultural business. However, due to corvids' quick wit, scarecrows are soon ignored and used as perches. Despite farmers' efforts to rid themselves of corvid pests, their attempts have only expanded corvid territories and strengthened their numbers.
Current systematics
Systematics
Biological systematics is the study of the diversification of terrestrial life, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees...
places corvids, based on physical characteristics other than their brains (the most developed of birds), in the lower middle of the passerines, contrary to earlier teleological classifications as "highest" songbirds due to their intelligence. As per one observer:
The other major group of highly intelligent birds of the order Psittaciformes (which includes 'true' parrots, cockatoo
Cockatoo
A cockatoo is any of the 21 species belonging to the bird family Cacatuidae. Along with the Psittacidae and the Strigopidae , they make up the parrot order Psittaciformes . Placement of the cockatoos as a separate family is fairly undisputed, although many aspects of the other living lineages of...
s and New Zealand parrots) is not closely related to corvids.
Disease
Corvids are reservoirs (carriers) for the West Nile VirusWest Nile virus
West Nile virus is a virus of the family Flaviviridae. Part of the Japanese encephalitis antigenic complex of viruses, it is found in both tropical and temperate regions. It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, domestic...
in the USA. They are infected by mosquitoes (the vectors), primarily of the Culex
Culex
Culex is a genus of mosquito, and is important in that several species serve as vectors of important diseases, such as West Nile virus, filariasis, Japanese encephalitis, St. Louis encephalitis and avian malaria....
species. Crow
Crow
Crows form the genus Corvus in the family Corvidae. Ranging in size from the relatively small pigeon-size jackdaws to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia, the 40 or so members of this genus occur on all temperate continents and several...
s and Raven
Raven
Raven is the common name given to several larger-bodied members of the genus Corvus—but in Europe and North America the Common Raven is normally implied...
s are quickly killed by this disease, so their deaths are an early-warning system when West Nile Virus arrives in an area (as are horse and other bird species deaths). One of the first signs that West Nile Virus first arrived in the USA in 1999 was the death of crows in New York.
Relationship with humans
Several different corvids, particularly ravenRaven
Raven is the common name given to several larger-bodied members of the genus Corvus—but in Europe and North America the Common Raven is normally implied...
s, have occasionally served as pets
PETS
PETS may be an acronym for:* Pet Travel Scheme, which allows animals to travel internationally without quarantine* Pets Evacuation and Transportation Standards Act...
, although they are not able to speak as readily as parrot
Parrot
Parrots, also known as psittacines , are birds of the roughly 372 species in 86 genera that make up the order Psittaciformes, found in most tropical and subtropical regions. The order is subdivided into three families: the Psittacidae , the Cacatuidae and the Strigopidae...
s and do not like being caged.
Role in myth and culture
Folklore often represents corvids as clever, and even mystical, animals. Some Native Americans, such as the Haida, believed that a raven created the earth and despite being a trickster spirit, ravens were popular on totems, credited with creating man, and responsible for placing the Sun in the sky.Various Germanic peoples
Germanic peoples
The Germanic peoples are an Indo-European ethno-linguistic group of Northern European origin, identified by their use of the Indo-European Germanic languages which diversified out of Proto-Germanic during the Pre-Roman Iron Age.Originating about 1800 BCE from the Corded Ware Culture on the North...
highly revered the raven. The major deity Odin
Odin
Odin is a major god in Norse mythology and the ruler of Asgard. Homologous with the Anglo-Saxon "Wōden" and the Old High German "Wotan", the name is descended from Proto-Germanic "*Wodanaz" or "*Wōđanaz"....
was so associated with ravens throughout history that he gained the kenning
Kenning
A kenning is a type of literary trope, specifically circumlocution, in the form of a compound that employs figurative language in place of a more concrete single-word noun. Kennings are strongly associated with Old Norse and later Icelandic and Anglo-Saxon poetry...
"raven god" and the raven banner
Raven banner
The raven banner was a flag, possibly totemic in nature, flown by various Viking chieftains and other Scandinavian rulers during the ninth, tenth and eleventh centuries A.D...
was the flag of various Viking Age
Viking Age
Viking Age is the term for the period in European history, especially Northern European and Scandinavian history, spanning the late 8th to 11th centuries. Scandinavian Vikings explored Europe by its oceans and rivers through trade and warfare. The Vikings also reached Iceland, Greenland,...
Scandinavian chieftains. He was also attended by Hugin and Munin
Hugin and Munin
In Norse mythology, Huginn and Muninn are a pair of ravens that fly all over the world, Midgard, and bring the god Odin information...
, two ravens
Common Raven
The Common Raven , also known as the Northern Raven, is a large, all-black passerine bird. Found across the northern hemisphere, it is the most widely distributed of all corvids...
who whispered news into his ears. The Valravn
Valravn
In Danish folklore, a valravn is a supernatural raven. The ravens appear in traditional Danish folksongs, where they are described as originating from ravens who consume the bodies of the dead on the battlefield, as capable of turning into the form of a knight after consuming the heart of a child,...
sometimes appears in modern Scandinavian folklore.
The 6th century BC Greek
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...
scribe Aesop
Aesop
Aesop was a Greek writer credited with a number of popular fables. Older spellings of his name have included Esop and Isope. Although his existence remains uncertain and no writings by him survive, numerous tales credited to him were gathered across the centuries and in many languages in a...
featured corvids as intelligent antagonists in many fables. Later, in western literature, popularized by American poet Edgar Allan Poe
Edgar Allan Poe
Edgar Allan Poe was an American author, poet, editor and literary critic, considered part of the American Romantic Movement. Best known for his tales of mystery and the macabre, Poe was one of the earliest American practitioners of the short story and is considered the inventor of the detective...
's work "The Raven
The Raven
"The Raven" is a narrative poem by American writer Edgar Allan Poe, first published in January 1845. It is often noted for its musicality, stylized language, and supernatural atmosphere. It tells of a talking raven's mysterious visit to a distraught lover, tracing the man's slow descent into madness...
", the Common Raven
Common Raven
The Common Raven , also known as the Northern Raven, is a large, all-black passerine bird. Found across the northern hemisphere, it is the most widely distributed of all corvids...
becomes a symbol of the main character's descent into madness.
Status and conservation
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, corvid fitness
Fitness (biology)
Fitness is a central idea in evolutionary theory. It can be defined either with respect to a genotype or to a phenotype in a given environment...
and reproduction, especially with many crows, has increased due to human development. The survival and reproductive success of certain crows and ravens is assisted by their close relationship with humans.
Human development provides additional resources by clearing land, creating shrublands rich in berries and insects. When the cleared land naturally replenishes, jays and crows use the young dense trees for nesting sites. Ravens typically use larger trees in denser forests.
Despite the fact that most corvids are not threatened (many even increasing due to human activity) a few species are in danger. For example, the destruction of the Southeast Asian rainforests is endangering mixed-species feeding flock
Mixed-species feeding flock
A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species, that join each other and move together while foraging...
s with members from the family Corvidae. Also, since its semiarid scrubland habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
is an endangered ecosystem
Ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....
, the Florida Scrub-jay has a small and declining population. A number of island species, which are more vulnerable to introduced species
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
and habitat loss, have been driven to extinction, such as the New Zealand Raven
New Zealand Raven
The New Zealand Raven was native to the North Island and South Island of New Zealand but is now extinct. There were two subspecies: the North Island Raven and the South Island Raven...
, or are threatened, like the Mariana Crow
Mariana Crow
The Mariana Crow is a species of the crow family from the north Pacific. It is an endangered species which has steadily declined in numbers since the 1960s.-Description:...
.
The American Crow
American Crow
The American Crow is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America...
population of the United States has grown over the years. It is possible that the American Crow, due to humans increasing suitable habitat, will drive out Northwestern
Northwestern Crow
The Northwestern Crow is an all-black passerine bird of the crow genus native to the northwest of North America. It is very similar to the more western forms of the widespread American Crow , but it averages slightly smaller with proportionately smaller feet and a slightly more slender bill...
and Fish Crow
Fish Crow
The Fish Crow is a species of crow that is associated with wetland habitats in the eastern and southeastern United States.-Taxonomy:The Fish Crow was first described by Alexander Wilson in 1812...
s.
Citations
(2005): Parentage and reproductive success in the white-throated magpie-jay, Calocitta formosa, a cooperative breeder with female helpers. Animal Behaviour 70(2): 375-385. (HTML abstract)|year=2004|id=40320|title=Aphelocoma coerulescens|downloaded=11 May 2006}} (2006): Landcover characterizations and Florida scrub-jay (Aphelocoma coerulescens) population dynamics. Biological Conservation 128(2): 169-181. PDF fulltext (2003): Social complexity and transitive inference in corvids. Animal Behaviour 65(3): 479-487. PDF fulltext (2006): Living with the Trickster: Crows, Ravens, and Human Culture. PLoS Biol 4 (1):e14. (2005): Corvid cognition. Current Biology 15(3): R80-R81. PDF fulltext (2004): The Mentality of Crows: Convergent Evolution of Intelligence in Corvids and Apes. Science 306(5703): 1903 - 1907 (2005): Inter-generic relationships of the crows, jays, magpies and allied groups (Aves: Corvidae) based on nucleotide sequence data. J. Avian Biol.Journal of Avian Biology
The Journal of Avian Biology is an international peer-reviewed ornithological journal published bimonthly, currently by Wiley-Blackwell on behalf of the Nordic Society Oikos. The journal is edited by Editor-in-Chief Thomas Alerstam and Deputy Editor-in-Chief Jan-Åke Nilsson.Journal of Avian Biology...
36: 222-234. PDF fulltext (2003) Ornithology (2nd edition). W.H. Freeman and Company, New York. ISBN 0-7167-2415-4 (1986) Crows of the world. (2nd edition). British Museum of Natural History. ISBN 0-565-00979-6 (2003): Pseudopodoces humilis, a misclassified terrestrial tit (Aves: Paridae) of the Tibetan Plateau: evolutionary consequences of shifting adaptive zones. Ibis
Ibis (journal)
Ibis, subtitled the International Journal of Avian Science, is the peer-reviewed scientific journal of the British Ornithologists' Union. Topics covered include ecology, conservation, behaviour, palaeontology, and taxonomy of birds. The editor-in-chief is Paul F. Donald. The journal is published by...
145(2): 185–202. PDF fulltext (2002): A Comparative Study of Geometric Rule Learning by Nutcrackers (Nucifraga columbiana), Pigeons (Columba livia), and Jackdaws (Corvus monedula). Journal of Comparative Psychology 116(4): 350-356. HTML abstract PDF fulltext (2006): A phylogenetic supertree of oscine passerine birds (Aves: Passeri). Zool. Scripta
Zoologica Scripta
Zoologica Scripta is a bi-monthly scientific journal on systematic zoology, published by Blackwell Publishing Limited, on behalf of the Norwegian Academy of Science and Letters and the Royal Swedish Academy of Sciences...
35(2): 149–186. (HTML abstract) (1979): [Ability of birds of the Corvidae family to operate by the empirical dimensions of figures]. Zhurnal vysshe nervno deiatelnosti imeni IP Pavlova 29(3): 590-597. [Article in Russian] PMID 112801 (HTML abstract) (2000): High frequency of extrapair fertilization in a plural breeding bird, the Mexican jay, revealed by DNA microsatellites. Animal Behaviour 60(6): 867-877 (2005): Effects of habitat disturbance on mixed species bird flocks in a tropical sub-montane rainforest. Biological Conservation 122(2): 193-204. (HTML abstract) (1993): Crows and Jays. Helm. ISBN 1-873403-18-6 (2005): In the Company of Crows and Ravens. Yale University Press, New Haven, Connecticut. ISBN 0-300-10076-0 (2006): Corvid response to human settlements and campgrounds: Causes, consequences, and challenges for conservation. Biological Conservation 130(2): 301-314. (HTML abstract) (1971): Ecological studies of the Rook Corvus frugilegus L. in northeast Scotland. Dispersion. J. Appl. Ecol. 8: 815-833.: The New Encyclopedia of Birds Oxford University Press: Oxford ISBN 0-19-852506-0 (2000): Bird Families of the World: Corvidae. Created 2000-JAN-30. Retrieved 2007-NOV-10. ([1991]): Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale University Press, New Haven, Connecticut. ISBN 0-300-04085-7 (2004): Why fight? Socially dominant jackdaws, Corvus monedula, have low fitness. Animal Behaviour 68: 777-783. (HTML abstract) (1937): The Eared Grebe and other Birds from the Pliocene of Kansas. Condor
Condor (journal)
The Condor is a peer-reviewed quarterly scientific journal covering ornithology and published by the Cooper Ornithological Society.-History:...
39(1): 40. PDF fulltext DjVu fulltext
External links
- Corvidae videos on the Internet Bird Collection
- corvids.de - Corvids-Literature-Database
- Corvidae sounds on xeno-canto.org
- Corvid Corner A site about the Corvidae
- AvesNoir A site about corvids in art, culture, and literature.
- Rooks reveal remarkable tool use
- Clever New Caledonian crows can use three tools