Corvidae is a

cosmopolitan Cosmopolitan may refer to: Food and drink * Cosmopolitan (cocktail), also known as a "Cosmo" History * Rootless cosmopolitan, a Soviet derogatory epithet during Joseph Stalin's anti-Semitic campaign of 1949–1953 Hotels and resorts * Cosmopoli ...

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

oscine A songbird is a bird belonging to the suborder Passeri of the perching birds (Passeriformes). Another name that is sometimes seen as the scientific or vernacular name is Oscines, from Latin ''oscen'', "songbird". The Passeriformes contains 5000 ...

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s that contains the

crow A crow is a bird of the genus '' Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifica ...

raven A raven is any of several larger-bodied bird species of the genus '' Corvus''. These species do not form a single taxonomic group within the genus. There is no consistent distinction between " crows" and "ravens", common names which are assigne ...

s, rooks,

jackdaw Jackdaws are two species of bird in the genus ''Coloeus'' closely related to, but generally smaller than, the crows and ravens (''Corvus''). ''Coloeus'' is sometimes treated as a subgenus of ''Corvus'', including by the IUCN.Madge & Burn (1994) ...

s, jays,

magpie Magpies are birds of the Corvidae family. Like other members of their family, they are widely considered to be intelligent creatures. The Eurasian magpie, for instance, is thought to rank among the world's most intelligent creatures, and is on ...

s, treepies,

chough There are two species of passerine birds commonly called chough ( ) that constitute the genus ''Pyrrhocorax'' of the Corvidae (crow) family of birds. These are the red-billed chough (''Pyrrhocorax pyrrhocorax''), and the Alpine chough (or yello ...

s, and nutcrackers. In

colloquial Colloquialism (), also called colloquial language, everyday language or general parlance, is the linguistic style used for casual (informal) communication. It is the most common functional style of speech, the idiom normally employed in conve ...

English, they are known as the crow family or corvids. Currently, 133 species are included in this family. The genus ''

Corvus ''Corvus'' is a widely distributed genus of medium-sized to large birds in the family Corvidae. It includes species commonly known as crows, ravens and rooks. The species commonly encountered in Europe are the carrion crow, the hooded crow ...

'', including the crows, rooks, and ravens, makes up over a third of the entire family. Corvids ( ravens) are the largest passerines. Corvids display remarkable

intelligence Intelligence has been defined in many ways: the capacity for abstraction, logic, understanding, self-awareness, learning, emotional knowledge, reasoning, planning, creativity, critical thinking, and problem-solving. More generally, it can ...

for animals of their size, and are among the most intelligent birds thus far studied. Specifically, members of the family have demonstrated

self-awareness In philosophy of self, self-awareness is the experience of one's own personality or individuality. It is not to be confused with consciousness in the sense of qualia. While consciousness is being aware of one's environment and body and lifest ...

mirror test The mirror test—sometimes called the mark test, mirror self-recognition (MSR) test, red spot technique, or rouge test—is a behavioral technique developed in 1970 by American psychologist Gordon Gallup Jr. as an attempt to determine whether an ...

s (

European magpie The Eurasian magpie or common magpie (''Pica pica'') is a resident breeding bird throughout the northern part of the Eurasian continent. It is one of several birds in the crow family (corvids) designated magpies, and belongs to the Holarctic r ...

s) and tool-making ability (e.g. crows and rooks), skills which until recently were thought to be possessed only by humans and a few other higher

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...

s. Their total brain-to-body mass ratio is equal to that of non-human

great ape The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); ''Gorilla'' (the ...

s and

cetacean Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel th ...

s, and only slightly lower than that of humans.Birding in India and South Asia
Corvidae
Retrieved 2007-NOV-10 They are medium to large in size, with strong feet and bills, rictal bristles, and a single

moult In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer ...

each year (most passerines moult twice). Corvids are found worldwide, except for the southern tip of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

and the polar

ice caps In glaciology, an ice cap is a mass of ice that covers less than of land area (usually covering a highland area). Larger ice masses covering more than are termed ice sheets. Description Ice caps are not constrained by topographical features ...

. The majority of the species are found in tropical South and

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

and in southern Asia, with fewer than 10 species each in Africa and

Australasia Australasia is a region that comprises Australia, New Zealand and some neighbouring islands in the Pacific Ocean. The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologic ...

. The genus ''Corvus'' has re-entered Australia in relatively recent geological prehistory, with five species and one subspecies there. Several species of raven have reached oceanic islands, and some of these species are now highly threatened with

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the Endling, last individual of the species, although the Functional ext ...

, or have already become extinct.

Systematics, taxonomy, and evolution

The name Corvidae for the

was introduced by the English zoologist

William Elford Leach William Elford Leach FRS (2 February 1791 – 25 August 1836) was an English zoologist and marine biologist. Life and work Elford Leach was born at Hoe Gate, Plymouth, the son of an attorney. At the age of twelve he began a medical appre ...

in a guide to the contents of the

British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It docum ...

published in 1820. Over the years, much disagreement has arisen on the exact evolutionary relationships of the corvid family and their relatives. What eventually seemed clear was that corvids are derived from

n ancestors, and spread throughout the world from there. 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 Currawongs are three species of medium-sized passerine birds belonging to the genus ''Strepera'' in the family Artamidae native to Australia. These are the grey currawong (''Strepera versicolor''), pied currawong (''S. graculina''), and black ...

birds of paradise The birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes. The majority of species are found in eastern Indonesia, Papua New Guinea and eastern Australia. The family has 44 species in 17 genera. The members of ...

, whipbirds, quail-thrushes, whistlers, monarch flycatchers and drongos,

shrike Shrikes () are passerine birds of the family Laniidae. The family is composed of 34 species in four genera. The family name, and that of the largest genus, '' Lanius'', is derived from the Latin word for "butcher", and some shrikes are also know ...

s, vireos, and vangas, 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 Old World orioles and vireos. Haubenhäher1

Clarification of the interrelationships of the corvids has been achieved based on

cladistic Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived char ...

analysis of several

DNA sequence DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. T ...

s. The jays and magpies do not constitute

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...

lineages, but rather seem to split up into an

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

and

Old World The "Old World" is a term for Afro-Eurasia that originated in Europe , after Europeans became aware of the existence of the Americas. It is used to contrast the continents of Africa, Europe, and Asia, which were previously thought of by thei ...

lineage, and an

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...

and Oriental lineage, respectively. These are not closely related among each other. The position of the azure-winged magpie, which has always been of undistinguished lineage, is less clear than previously thought. The crested jayshrike (''Platylophus galericulatus'') is traditionally included in the Corvidae, but is not a true member of this family, being closer to the helmetshrikes ( Malaconotidae) or

s ( Laniidae). Likewise, the Hume's ground "jay" (''Pseudopodoces humilis'') is, in fact, a member of the tit family,

Paridae The tits, chickadees, and titmice constitute the Paridae, a large family of small passerine birds which occur mainly in the Northern Hemisphere and Africa. Most were formerly classified in the genus ''Parus''. Members of this family are common ...

. The following tree represents current insights in the

phylogeny A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological s ...

of the Crow family, according to J. Boyd:

Fossil record

The earliest corvid

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s date to mid-

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

Europe, 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 is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...

. The known prehistoric corvid genera appear to be mainly of the New World and Old World jay and Holarctic magpie lineages: * '' Miocorvus'' (

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million ...

of Sansan, Gers in southwestern

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

) * '' Miopica'' (Middle Miocene of SW Ukraine) * '' Miocitta'' (Pawnee Creek Late Miocene of Logan County, US) * Corvidae gen. et sp. indet. (Edson

Early Pliocene Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * ...

of Sherman County, Kansas, USA) * '' Protocitta'' (Early Pleistocene of Reddick, US) * Corvidae gen. et sp. indet. (Early/Middle Pleistocene of Sicily) - probably belongs in an extant genus * '' Henocitta'' (Arredondo Clay Middle Pleistocene of Williston, US) In addition, there are numerous fossil species of extant genera since the

Mio Mio or MIO may refer to: shortened form of Mioritic Shepherd dog or Mioritic sheepdog; a Romanian mountain dog. Places * Mio, Michigan, a town in the US Music * ''Mío'', 2011 album by David Bustamante * " Mío", 1992 song by Paulina Rubio Bra ...

–

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 Corvids are large to very large

s with a robust build and strong legs; all species, except the pinyon jay, have

nostril A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...

s covered by bristle-like feathers. Many corvids of temperate zones have mainly black or blue coloured

plumage Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...

; 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

order. The smallest corvid is the dwarf jay (''Aphelocoma nana''), at and . The largest corvids are the

common raven The common raven (''Corvus corax'') is a large all-black passerine bird. It is the most widely distributed of all corvids, found across the Northern Hemisphere. It is a raven known by many names at the subspecies level; there are at least ...

(''Corvus corax'') and the thick-billed raven (''Corvus crassirostris''), both of which regularly exceed and . 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 migrate significantly. However, during a shortage of food, irruptive 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. Since crows and magpies have benefited and even increased in numbers due to human development, it was suggested that this might cause increased rates of nest predation of smaller bird species, leading to declines. Several studies have shown this concern to be unfounded. One study examined

American crow The American crow (''Corvus brachyrhynchos'') is a large passerine bird species of the family Corvidae. It is a common bird found throughout much of North America. American crows are the New World counterpart to the carrion crow of Europe an ...

s, which had increased in numbers, were a suspect in nest predation of threatened marbled murrelets. However,

Steller's jay Steller's jay (''Cyanocitta stelleri'') is a bird native to western North America and the mountains of Central America, closely related to the blue jay found in eastern North America. It is also known as the long-crested jay, mountain jay, and p ...

s, which are successful independently of human development, are more efficient in plundering small birds' nests than

s and

s. Therefore, the human relationship with crows and ravens did not significantly increase nest predation when compared to other factors, such as

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

. Similarly, a study examining the decline of British songbirds found no link between

Eurasian magpie The Eurasian magpie or common magpie (''Pica pica'') is a resident breeding bird throughout the northern part of the Eurasian continent. It is one of several birds in the crow family (corvids) designated magpies, and belongs to the Holarctic ...

numbers and population changes of 23 songbird species.

Behaviour

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 A game is a structured form of play, usually undertaken for entertainment or fun, and sometimes used as an educational tool. Many games are also considered to be work (such as professional players of spectator sports or games) or art (suc ...

s. Documented group games follow "king of the mountain" or "follow the leader" patterns. 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 The blue jay (''Cyanocitta cristata'') is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations are ...

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.

Food and feeding

The natural diet of many corvid species is omnivorous, consisting of

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...

s, nestlings, small mammals, berries, fruits, seeds, and

carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...

. However, some corvids, especially the crows, have adapted well to human conditions, and have come to rely on human food sources. In a US study of

s, and

s around campgrounds and human settlements, the crows appeared to have the most diverse diet of all, taking

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows: * Human i ...

foods, such as: bread, spaghetti, fried potatoes, dog food, sandwiches, and livestock feed. The increase in available human food sources is contributing to population rises 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 Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grasshoppe ...

, and harmful weeds.Shades of Night
The Aviary
. Version of 2004-JUL-21. Retrieved 2007-NOV-10. Some corvids will eat

, 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.

Reproduction

Many species of corvid are

territorial A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or an ...

, 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 (''Corvus frugilegus'') is a bird of the corvid family. Rook or rooks may also refer to: Games *Rook (chess), a piece in chess *Rook (card game), a trick-taking card game Military *Sukhoi Su-25 The Sukhoi Su-25 ''Grach'' (russian: � ...

counted in

Scotland Scotland (, ) is a country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to ...

. Some, including the rook and the

, 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; jackdaws are known to breed in buildings and in rabbit warrens. 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 use several different forms of parental care, including bi-parental care and

cooperative breeding Cooperative breeding is a social system characterized by alloparental care: offspring receive care not only from their parents, but also from additional group members, often called helpers. Cooperative breeding encompasses a wide variety of group s ...

Cooperative breeding Cooperative breeding is a social system characterized by alloparental care: offspring receive care not only from their parents, but also from additional group members, often called helpers. Cooperative breeding encompasses a wide variety of group s ...

takes place when parents are helped in raising their offspring, usually by relatives, but also sometimes by non-related adults. Such

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 the ...

in most cooperatively-breeding birds are males, while females join other groups. White-throated magpie-jays are cooperatively-breeding corvids where the helpers are mostly female.

Intelligence

Jerison (1973) has suggested that the degree of brain

encephalization Encephalization quotient (EQ), encephalization level (EL), or just encephalization is a relative brain size measure that is defined as the ratio between observed to predicted brain mass for an animal of a given size, based on nonlinear regress ...

(the ratio of brain size to body size, EQ) may correlate with an animal's intelligence and cognitive skills. Corvids and psittacids have higher EQ than other bird families, similar to that of the apes. Among the Corvidae, ravens possess the largest brain to body size ratio. In addition to the high EQ, the Corvid's intelligence is boosted by their living environment. Firstly, Corvids are found in some of the harshest environments on Earth, where surviving requires higher intelligence and better adaptations. Secondly, most of the Corvids are omnivorous, suggesting that they are exposed to more different stimuli and environments. Furthermore, many corvid species live in a large family group, and demonstrate high social complexities. 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. 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

meta-analysis A meta-analysis is a statistical analysis that combines the results of multiple scientific studies. Meta-analyses can be performed when there are multiple scientific studies addressing the same question, with each individual study reporting m ...

testing how often birds invented new ways to acquire food in the wild found corvids to be the most innovative birds. A 2004 review suggested that their cognitive abilities are on par with those of non-human

great apes The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic family of primates that includes eight extant species in four genera: '' Pongo'' (the Bornean, Sumatran and Tapanuli orangutan); ''Gorilla'' (the ...

. Despite structural differences, the brains of corvids and great apes both evolved the ability to make geometrical measurements.

Empathy-consolation

Ravens are found to show bystander affiliation, and solicited bystander affiliation after aggressive conflicts. Most of the time, bystanders already sharing a valuable relationship with the victim are more likely to affiliate with the victim to alleviate the victim's distress ("consolation") as a representation of

empathy Empathy is the capacity to understand or feel what another person is experiencing from within their frame of reference, that is, the capacity to place oneself in another's position. Definitions of empathy encompass a broad range of social, co ...

. Ravens are believed to be able to be sensitive to other's emotions.

Empathy-emotional contagion

Emotion Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definitio ...

contagion refers to the

emotional state Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definition. ...

matching between individuals. Adriaense et al. (2018) used a

bias Bias is a disproportionate weight ''in favor of'' or ''against'' an idea or thing, usually in a way that is closed-minded, prejudicial, or unfair. Biases can be innate or learned. People may develop biases for or against an individual, a group ...

paradigm to quantify

emotional valence Valence, or hedonic tone, is the affective quality referring to the intrinsic attractiveness/"good"-ness (positive valence) or averseness/"bad"-ness (negative valence) of an event, object, or situation. The term also characterizes and categor ...

, which along with emotional arousal, define emotions. They manipulated the positive and negative affective states in the demonstrator ravens, which showed significantly different responses to the two states: behaving pessimism to the negative states, and optimism to the positive states. Then, the researchers trained another observer raven to first observe the demonstrator's responses. The observer raven was then presented with ambiguous stimuli. The experiment results confirmed the existence of negative emotional contagions in ravens, while the positive emotional contagion remained unclear. Therefore, ravens are capable of both discerning the negative emotions in their conspecifics and showing signs of empathy.

Interspecific communications

Interspecific communications are evolutionarily beneficial for species living in the same environment. Facial expressions are the most widely used method to express emotions by humans. Tate et al. (2006) explored the issue of non-human mammals processing the visual cues from faces to achieve interspecific communication with humans. Researchers also examined the avian species' capabilities to interpret this non-verbal communication, and their extent of sensitivity to human emotions. Based on the experimental subject of American Crows' behavioral changes to varying human gazes and facial expressions, Clucas et al. (2013) identified that crows are able to change their behaviors to human emotions. They further suggested that the high intelligence of the crows enables them to adapt well to human-dominated environments.

Personality conformity

It is considered difficult to study emotions in animals when humans could not communicate with them. One way to identify animal

personality Personality is the characteristic sets of behaviors, cognitions, and emotional patterns that are formed from biological and environmental factors, and which change over time. While there is no generally agreed-upon definition of personality, ...

traits is to observe the consistency of the individual's behavior over time and circumstances. For group-living species, there are two opposing hypotheses regarding the assortment of personalities within a group: the social niche specialization hypothesis, and the conformity hypothesis. To test these two hypotheses, McCune et al. (2018) performed an experiment on the boldness of two species in Corvidae: the

Mexican Jay The Mexican jay (''Aphelocoma wollweberi'') Etymology: ''Aphelocoma'', from Latinized Ancient Greek ''apheles-'' (from ἀφελής-) "simple" + Latin ''coma'' (from Greek ''kome'' κόμη) "hair", in reference to the lack of striped or banded ...

and California Scrub-Jay. Their results confirmed the conformity hypothesis, supported by the significant differences in the group effects.

Social construction

The individual personality is both determined by genetics and shaped by social contexts. Miller et al. (2016) examined the role of the developmental and social environment in personality formation in common ravens and carrion crows, which are highly social corvids. The researchers highlighted the correlation between social contexts and an individual's consistent behavior over time (personality), by showing that conspecific presence promoted the behavioral similarities between individuals. Therefore, the researchers demonstrated that social contexts had a significant impact on the development of the raven's and crow's personalities.

Social complexity

The social complexity hypothesis suggests that living in a social group enhances the cognitive abilities of animals. Corvid ingenuity is represented through their feeding skills,

memorization Memorization is the process of committing something to memory. It is a mental process undertaken in order to store in memory for later recall visual, auditory, or tactical information. The scientific study of memory is part of cognitive neuros ...

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, as well as contributing to the spread of information between members of the group.

Consciousness, culture-rudiments, and neurology

The

is the only non-mammal species known to be able to recognize itself in a

, although later research could not replicate this finding. Studies using very similar setups could not find such behaviour in other corvids (e.g., Carrion crows). Magpies have been observed taking part in elaborate grieving rituals, which have been likened to human

funeral A funeral is a ceremony connected with the final disposition of a corpse, such as a burial or cremation, with the attendant observances. Funerary customs comprise the complex of beliefs and practices used by a culture to remember and respect ...

s, including laying grass wreaths.Animal emotions, wild justice and why they matter: Grieving magpies, a pissy baboon, and empathic elephants
Emotion, Space and Society xxx (2009) 1–4, Marc Bekoff Marc Bekoff, at the

University of Colorado The University of Colorado (CU) is a system of public universities in Colorado. It consists of four institutions: University of Colorado Boulder, University of Colorado Colorado Springs, University of Colorado Denver, and the University o ...

, argues that it shows that they are capable of feeling complex emotions, including

grief Grief is the response to loss, particularly to the loss of someone or some living thing that has died, to which a bond or affection was formed. Although conventionally focused on the emotional response to loss, grief also has physical, cogniti ...

. Furthermore,

carrion crow The carrion crow (''Corvus corone'') is a passerine bird of the family Corvidae and the genus ''Corvus'' which is native to western Europe and the eastern Palearctic. Taxonomy and systematics The carrion crow was one of the many species or ...

s show a neuronal response that correlates with their

perception Perception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous syste ...

of a stimulus, which some scientists have argued to be an empirical marker of ( avian/corvid) sensory consciousness—the conscious perception of sensory input—in the crows which do not have a

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting o ...

. A related study shows that the birds' pallium's neuroarchitecture is reminiscent of the mammalian cortex.

Tool use, memory, and complex rational thought

There are also specific examples of corvid cleverness. One

was documented cracking 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 (that is, 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 places up to nine months later. It is suggested that vertical landmarks (like trees) are used to remember locations. There has also been evidence that

California scrub jay The California scrub jay (''Aphelocoma californica'') is a species of scrub jay native to western North America. It ranges from southern British Columbia throughout California and western Nevada near Reno to west of the Sierra Nevada. The Calif ...

s, which store perishable foods, not only remember where they stored their food, but for how long. This has been compared to

episodic memory Episodic memory is the memory of everyday events (such as times, location geography, associated emotions, and other contextual information) that can be explicitly stated or conjured. It is the collection of past personal experiences that occurred ...

, previously thought unique to humans.

New Caledonian crow The New Caledonian crow (''Corvus moneduloides'') is a medium-sized member of the family Corvidae, native to New Caledonia. The bird is often referred to as the 'qua-qua' due to its distinctive call. It eats a wide range of food, including man ...

s (''Corvus moneduloides'') are notable for their highly developed tool fabrication. They make angling tools of twigs and leaves trimmed into hooks, and then subsequently use the hooks to pull insect larvae from tree holes. Tools are engineered according to task, and apparently, also to learned preferences. Recent studies revealed abilities to solve complicated problems, which suggested high levels of innovation of a complex nature. Other corvids that have been observed using tools include: the

blue jay The blue jay (''Cyanocitta cristata'') is a passerine bird in the family Corvidae, native to eastern North America. It lives in most of the eastern and central United States; some eastern populations may be migratory. Resident populations are ...

, and green jay. Researchers have discovered that

s don't just use single objects as tools—they can also construct novel compound tools through assemblage of otherwise non-functional elements. 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 (''Nucifraga columbiana''), sometimes referred to as Clark's crow or woodpecker crow, is a passerine bird in the family Corvidae, native to the mountains of western North America. The nutcracker is an omnivore, but subsists mai ...

s and

s were compared in a 2002 study based on geometric rule learning. The corvids, along with a

domestic pigeon The domestic pigeon (''Columba livia domestica'' or ''Columba livia'' ''forma'' ''domestica'') is a pigeon subspecies that was derived from the rock dove (also called the rock pigeon). The rock pigeon is the world's oldest domesticated bird. ...

, 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.

Implications and specific comparisons with other animals

Proportions of correct responses as a function of species

The

scarecrow A scarecrow is a decoy or mannequin, often in the shape of a human. Humanoid scarecrows are usually dressed in old clothes and placed in open fields to discourage birds from disturbing and feeding on recently cast seed and growing crops.Lesle ...

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. Contrary to earlier

teleological Teleology (from and )Partridge, Eric. 1977''Origins: A Short Etymological Dictionary of Modern English'' London: Routledge, p. 4187. or finalityDubray, Charles. 2020 912Teleology" In ''The Catholic Encyclopedia'' 14. New York: Robert Appleton ...

classifications, in which they were seen as "highest" songbirds due to their intelligence, current

systematics Biological systematics is the study of the diversification of living forms, both past and present, and the relationships among living things through time. Relationships are visualized as evolutionary trees (synonyms: cladograms, phylogenetic t ...

might place corvids—based on their total number of physical characteristics, instead of just their brains (which are the most developed of birds)—in the lower middle of the passerine evolutionary tree, dependent on which subgroup is chosen as the most derived. As per one observer: The other major group of highly intelligent birds of the order Psittaciformes (which includes 'true' parrots,

cockatoo A cockatoo is any of the 21 parrot species belonging to the family Cacatuidae, the only family in the superfamily Cacatuoidea. Along with the Psittacoidea (true parrots) and the Strigopoidea (large New Zealand parrots), they make up the orde ...

s, and

New Zealand parrot The New Zealand parrot family, Strigopidae,Nestoridae and Strigopidae are described in the same article, Bonaparte, C.L. (1849) ''Conspectus Systematis Ornithologiae''. Therefore, under rules of the ICZN, the first reviser determines priority, ...

s) is not closely related to corvids. A study found that four-months-old ravens can have physical and social cognitive skills similar to that of adult great apes, and concluded that the “dynamic of the different influences that, during

ontogeny Ontogeny (also ontogenesis) is the origination and development of an organism (both physical and psychological, e.g., moral development), usually from the time of fertilization of the egg to adult. The term can also be used to refer to the s ...

, contributes to adult cognition” is required for the study of cognition. CC-BY icon

Available unde
CC BY 4.0

Disease

Corvids are reservoirs (carriers) for the

West Nile virus West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family '' Flaviviridae'', from the genus '' Flavivirus'', which also contains the Zika virus, dengue virus, and yellow fever virus. The v ...

in the United States. They are infected by mosquitoes (the vectors), primarily of the ''

Culex ''Culex'' is a genus of mosquitoes, several species of which serve as vectors of one or more important diseases of birds, humans, and other animals. The diseases they vector include arbovirus infections such as West Nile virus, Japanese encep ...

'' species.

Crow A crow is a bird of the genus '' Corvus'', or more broadly a synonym for all of ''Corvus''. Crows are generally black in colour. The word "crow" is used as part of the common name of many species. The related term "raven" is not pinned scientifica ...

s and

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 horses and other bird-species deaths). One of the first signs that West Nile virus first arrived in the US in 1999 was the death of crows in

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

Relationship with humans

Several different corvids, particularly

s, have occasionally served as

pets A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive appearances, intelligence ...

, although they are not able to speak as readily as

parrot Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoide ...

s, and are not suited to a caged environment. It is illegal to own corvids, or any other

migratory bird Bird migration is the regular seasonal movement, often north and south along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting b ...

, without a permit in North America, due to the Migratory Bird Act. Humans have been able to coexist with many members of the Corvidae family throughout history, most notably

crows The Common Remotely Operated Weapon Station (CROWS) is a series of remote weapon stations used by the US military on its armored vehicles and ships. It allows weapon operators to engage targets without leaving the protection of their vehicle. ...

and

s (see: “Role in myth and culture” section below). These positive interactions have extended into modern times.

Role in myth and culture

Folklore often represents corvids as clever, and even mystical, animals. Some Native Americans, such as the

Haida Haida may refer to: Places * Haida, an old name for Nový Bor * Haida Gwaii, meaning "Islands of the People", formerly called the Queen Charlotte Islands * Haida Islands, a different archipelago near Bella Bella, British Columbia Ships * , a ...

, believed that a raven created the earth, and despite being a trickster spirit, ravens were popular on totems, credited with creating man, and considered responsible for placing the Sun in the sky. Due to their

diet, the

Celtic Celtic, Celtics or Keltic may refer to: Language and ethnicity *pertaining to Celts, a collection of Indo-European peoples in Europe and Anatolia **Celts (modern) *Celtic languages **Proto-Celtic language *Celtic music *Celtic nations Sports Foo ...

peoples strongly associated corvids with war, death, and the battlefield; their great intelligence meant that they were often considered messengers, or manifestations of the gods, such as Bendigeidfran (Welsh for “Blessed Crow”) or the Irish Morrigan (Middle Irish for “Great Queen”), both who were

underworld deities The underworld, also known as the netherworld or hell, is the supernatural world of the dead in various religious traditions and myths, located below the world of the living. Chthonic is the technical adjective for things of the underworld. ...

that may be related to the later Arthurian

Fisher King The Fisher King is a figure in Arthurian legend, the last in a long line of British kings tasked with guarding the Holy Grail. The Fisher King is both the protector and physical embodiment of his lands, but a wound renders him incapable and hi ...

. The Welsh '' Dream of Rhonabwy'' illustrates well the association of ravens with war. In many parts of Britain, gatherings of crows, or more often magpies, are counted using the divination rhyme: “''one for sorrow, two for joy, three for a girl, four for a boy, five for silver, six for gold, seven for a secret never to be told.”'' Another rhyme is: “''one for sorrow, two for mirth, three for a funeral, four for a birth, five for heaven, six for hell, and seven for the Devil, his own sel.”'' Cornish superstition holds that when a lone magpie is encountered, it must be loudly greeted with respect. Various

Germanic peoples The Germanic peoples were historical groups of people that once occupied Central Europe and Scandinavia during antiquity and into the early Middle Ages. Since the 19th century, they have traditionally been defined by the use of ancient and ear ...

highly revered the raven, and the raven was often depicted as a motif on shields or other war gear in

Anglo-Saxon art Anglo-Saxon art covers art produced within the Anglo-Saxon period of English history, beginning with the Migration period style that the Anglo-Saxons brought with them from the continent in the 5th century, and ending in 1066 with the Norman ...

, such as the

Sutton Hoo Sutton Hoo is the site of two early medieval cemeteries dating from the 6th to 7th centuries near the English town of Woodbridge. Archaeologists have been excavating the area since 1938, when a previously undisturbed ship burial containing ...

burial, and

Vendel period In Swedish prehistory, the Vendel Period ( sv, Vendeltiden; 540–790 AD) appears between the Migration Period and the Viking Age. The name is taken from the rich boat inhumation cemetery at Vendel parish church, Uppland. This is a period wit ...

art. The major deity,

Odin Odin (; from non, Óðinn, ) is a widely revered god in Germanic paganism. Norse mythology, the source of most surviving information about him, associates him with wisdom, healing, death, royalty, the gallows, knowledge, war, battle, victory, ...

, was so commonly associated with ravens throughout history that he gained the

kenning A kenning ( Icelandic: ) is a figure of speech in the type of circumlocution, a compound that employs figurative language in place of a more concrete single-word noun. Kennings are strongly associated with Old Norse-Icelandic and Old English ...

“Raven God,” and the

raven banner The raven banner ( non, hrafnsmerki ; enm, hravenlandeye) was a flag, possibly totemic in nature, flown by various Viking chieftains and other Scandinavian rulers during the 9th, 10th and 11th centuries. The flag, as depicted in Norse artwork, ...

was the flag of various

Viking Age The Viking Age () was the period during the Middle Ages when Norsemen known as Vikings undertook large-scale raiding, colonizing, conquest, and trading throughout Europe and reached North America. It followed the Migration Period and the Germ ...

Scandinavian chieftains. Odin was also attended by

Hugin and Munin In Norse mythology, Huginn (Old Norse: "thought"Orchard (1997:92).) and Muninn (Old Norse "memory"Orchard (1997:115). or "mind"Lindow (2001:186).) are a pair of ravens that fly all over the world, Midgard, and bring information to the god Odin. ...

, two ravens who flew all over the world, and whispered information they acquired into his ears. The Valravn sometimes appeared in modern Scandinavian folklore. On a shield and purse lid excavated among the

treasures, imagery of stylised corvids with scrolled beaks are meticulously detailed in the decorative enamel work. The corvid symbolism reflected their common

totemic A totem (from oj, ᑑᑌᒼ, italics=no or '' doodem'') is a spirit being, sacred object, or symbol that serves as an emblem of a group of people, such as a family, clan, lineage, or tribe, such as in the Anishinaabe clan system. While ''the ...

status to the Anglo-Saxons, whose pre-Christian indigenous beliefs were of the same origin as that of the aforementioned Vikings. The sixth century BCE

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

scribe

Aesop Aesop ( or ; , ; c. 620–564 BCE) was a Greek fabulist and storyteller credited with a number of fables now collectively known as ''Aesop's Fables''. Although his existence remains unclear and no writings by him survive, numerous tales c ...

featured corvids as intelligent antagonists in many fables. Later, in western literature, popularized by American poet

Edgar Allan Poe Edgar Allan Poe (; Edgar Poe; January 19, 1809 – October 7, 1849) was an American writer, poet, editor, and literary critic. Poe is best known for his poetry and short stories, particularly his tales of mystery and the macabre. He is wid ...

's work "

The Raven "The Raven" is a narrative poem by American writer Edgar Allan Poe. First published in January 1845, the poem is often noted for its musicality, stylized language, and supernatural atmosphere. It tells of a distraught lover who is paid a myst ...

", the

becomes a symbol of the main character's descent into madness. The children's book '' Mrs. Frisby and the Rats of NIMH'' and its animated film adaptation features a protagonist crow named Jeremy. Corvus hawaiiensis FWS

Status and conservation

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 forest. 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 rainforest is endangering

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. These are ...

s with members from the family Corvidae. Also, since its

semiarid A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi- ...

scrubland

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

is an endangered

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

, the

Florida scrub jay The Florida scrub jay (''Aphelocoma coerulescens'') 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 and one of only 15 species endemic to the continental United State ...

has a small and declining population. A number of island species, which are more vulnerable to

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...

and habitat loss, have been driven to extinction, such as the

New Zealand raven The New Zealand raven (''Corvus antipodum'') was native to the North Island and South Island of New Zealand but has been extinct since the 16th century. There were two subspecies: the North Island raven (''Corvus antipodum antipodum'') and the So ...

, or are threatened, like the Mariana crow. The

population of the United States has grown over the years. It is possible that the American crow, due to humans increasing suitable habitat, will cause Northwestern crows and

fish crow The fish crow (''Corvus ossifragus'') is a species of crow associated with wetland habitats in the eastern and southeastern United States. Taxonomy and etymology The fish crow was given its binomial name by the Scottish ornithologist Alexan ...

s to decline.

Species

FAMILY CORVIDAE Rufous Treepie I IMG 9850

Flickr_-_don_macauley_-_Corvus_crassirostris

Chough There are two species of passerine birds commonly called chough ( ) that constitute the genus ''Pyrrhocorax'' of the Corvidae (crow) family of birds. These are the red-billed chough (''Pyrrhocorax pyrrhocorax''), and the Alpine chough (or yello ...

s **Genus '' Pyrrhocorax'' *** Alpine chough, ''Pyrrhocorax graculus'' ***

Red-billed chough The red-billed chough, Cornish chough or simply chough ( ; ''Pyrrhocorax pyrrhocorax''), is a bird in the crow family, one of only two species in the genus '' Pyrrhocorax''. Its eight subspecies breed on mountains and coastal cliffs from the w ...

, ''Pyrrhocorax pyrrhocorax'' * Treepies **Genus '' Crypsirina'' *** Hooded treepie, ''Crypsirina cucullata'' *** Racket-tailed treepie, ''Crypsirina temia'' **Genus '' Dendrocitta'' *** Andaman treepie, ''Dendrocitta bayleyi'' *** Bornean treepie, ''Dendrocitta cinerascens'' *** Grey treepie, ''Dendrocitta formosae'' *** Collared treepie, ''Dendrocitta frontalis'' *** White-bellied treepie, ''Dendrocitta leucogastra'' *** Sumatran treepie, ''Dendrocitta occipitalis'' *** Rufous treepie, ''Dendrocitta vagabunda'' **Genus '' Platysmurus'' *** Malayan black magpie, ''Platysmurus leucopterus'' *** Bornean black magpie, ''Platysmurus aterrimus'' **Genus '' Temnurus'' *** Ratchet-tailed treepie, ''Temnurus temnurus'' *Oriental

s **Genus '' Cissa'' *** Common green magpie, ''Cissa chinensis'' ***

Indochinese green magpie The Indochinese green magpie (''Cissa hypoleuca'') or yellow-breasted magpie, is a passerine bird of the crow family, Corvidae. It is native to mainland southeast Asia (Indochina) and adjacent China. This species' yellow undersides make it disti ...

, ''Cissa hypoleuca'' *** Javan green magpie, ''Cissa thalassina'' *** Bornean green magpie, ''Cissa jefferyi'' **Genus ''

Urocissa ''Urocissa'' is a genus of birds in the Corvidae, a family that contains the crows, jays, and magpies. The genus was established by German ornithologist Jean Cabanis in 1850. The type species was subsequently designated as the red-billed blue ...

'' ***

Taiwan blue magpie The Taiwan blue magpie (''Urocissa caerulea''), also called the Taiwan magpie, Formosan blue magpie (), or the "long-tailed mountain lady" (; Taiwanese Hokkien: Tn̂g-boé soaⁿ-niû), is a bird species in the crow family. It is endemic to Taiwan ...

, ''Urocissa caerulea'' ***

Red-billed blue magpie The red-billed blue magpie (''Urocissa erythroryncha'') is a species of bird in the crow family, Corvidae. It is about the same size as the Eurasian magpie, but has a much longer tail, one of the longest of any corvid. It is long and weighs . T ...

, ''Urocissa erythrorhyncha'' *** Yellow-billed blue magpie, ''Urocissa flavirostris'' *** Sri Lanka blue magpie, ''Urocissa ornata'' *** White-winged magpie, ''Urocissa whiteheadi'' *Old World jays **Genus '' Garrulus'' ***

Eurasian jay The Eurasian jay (''Garrulus glandarius'') is a species of passerine bird in the crow family Corvidae. It has pinkish brown plumage with a black stripe on each side of a whitish throat, a bright blue panel on the upper wing and a black tail. The ...

, ''Garrulus glandarius'' *** Black-headed jay, ''Garrulus lanceolatus'' *** Lidth's jay, ''Garrulus lidthi'' **Genus '' Podoces'' – ground jays *** Xinjiang ground jay, ''Podoces biddulphi'' *** Mongolian ground jay, ''Podoces hendersoni'' *** Turkestan ground jay, ''Podoces panderi'' *** Iranian ground jay, ''Podoces pleskei'' *Piapiac **Genus '' Ptilostomus'' *** Piapiac, ''Ptilostomus afer'' *Stresemann's bushcrow **Genus '' Zavattariornis'' *** Stresemann's bushcrow, ''Zavattariornis stresemanni'' * Nutcrackers **Genus '' Nucifraga'' ***

Spotted nutcracker The spotted nutcracker, Eurasian nutcracker, or simply nutcracker (''Nucifraga caryocatactes'') 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 ...

, ''Nucifraga caryocatactes'' *** Kashmir nutcracker, ''Nucifraga multipunctata'' ***

, ''Nucifraga columbiana'' *Holarctic

s **Genus '' Pica'' ***

Black-billed magpie The black-billed magpie (''Pica hudsonia''), also known as the American magpie, is a bird in the corvid family found in the western half of North America. It is black and white, with black areas on the wings and tail showing iridescent hints o ...

, ''Pica hudsonia'' *** Yellow-billed magpie, ''Pica nuttalli'' ***

, ''Pica pica'' ****

Korean magpie The Oriental magpie (''Pica serica'') is a species of magpie found from south-eastern Russia and Myanmar to eastern China, Korea, Taiwan, Japan and northern Indochina. It is also a common symbol of the Korean identity, and has been adopted as t ...

, ''Pica (pica) serica'' **Genus '' Cyanopica'' *** Azure-winged magpie, ''Cyanopica cyanus'' *** Iberian magpie, ''Cyanopica cooki'' *True crows (

s and

) **Genus ''

'' ***''Australian and Melanesian'' species **** Little crow, ''Corvus bennetti'' ****

Australian raven The Australian raven (''Corvus coronoides'') is a passerine bird in the genus '' Corvus'' native to much of southern and northeastern Australia. Measuring in length, it has all-black plumage, beak and mouth, as well as strong grey-black legs an ...

, ''Corvus coronoides'' ****

Bismarck crow The Bismarck crow (''Corvus insularis'') is a species of crow found in the Bismarck Archipelago. It was considered by many authorities to be a subspecies of the Torresian crow The Torresian crow (''Corvus orru''), also called the Australian cro ...

, ''Corvus insularis'' **** Brown-headed crow, ''Corvus fuscicapillus'' ****

Bougainville crow The Bougainville crow (''Corvus meeki'') 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. Within its range it is ...

, ''Corvus meeki'' ****

Little raven The little raven (''Corvus mellori'') is a species of the family Corvidae that is native to southeastern Australia. An adult individual is about in length, with completely black plumage, beak, and legs; as with all Australian species of ''Corv ...

, ''Corvus mellori'' ****

, ''Corvus moneduloides'' ****

Torresian crow The Torresian crow (''Corvus orru''), also called the Australian crow or Papuan crow, is a passerine bird in the crow family native to the north and west of Australia and nearby islands in Indonesia and Papua New Guinea. The species has a bla ...

, ''Corvus orru'' **** Forest raven, ''Corvus tasmanicus'' ***** Relict raven, ''Corvus (tasmanicus) boreus'' **** Grey crow, ''Corvus tristis'' **** Long-billed crow, ''Corvus validus'' **** White-billed crow, ''Corvus woodfordi'' ***''Pacific island'' species **** Alalā (Hawaiian crow), ''Corvus hawaiiensis'' (formerly ''Corvus tropicus'') (

extinct in the wild A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as known only by living members kept in captivity or as a naturalized population outside its historic range due t ...

) **** Mariana crow, ''Corvus kubaryi'' ***''Tropical Asian'' species **** Daurian jackdaw, ''Corvus dauuricus'' **** Slender-billed crow, ''Corvus enca'' **** Palawan crow, ''Corvus pusillus'' **** Flores crow, ''Corvus florensis'' ****

Large-billed crow The large-billed crow (''Corvus macrorhynchos''), formerly referred to widely as the jungle crow, is a widespread Asian species of crow. It is very adaptable and is able to survive on a wide range of food sources, making it capable of colonizing ...

, ''Corvus macrorhynchos'' ****

Eastern jungle crow The eastern jungle crow (''Corvus levaillantii'') is a bird in the family Corvidae. It is found in China, Bangladesh, India, Myanmar, Nepal, Bhutan, and Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of ...

, ''Corvus levaillantii'' ****

Indian jungle crow The Indian jungle crow (''Corvus culminatus'') is a species of crow found across the Indian Subcontinent south of the Himalayas. It is very common and readily distinguished from the house crow (''Corvus splendens''), which has a grey neck. In the ...

, ''Corvus culminatus'' ****

House crow The house crow (''Corvus splendens''), also known as the Indian, greynecked, Ceylon or 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. ...

, ''Corvus splendens'' ****

Collared crow The collared crow (''Corvus torquatus''), also known as the ring-necked crow or white-collared crow, is a member of the family Corvidae native to China and north of Vietnam. Description It is about 52–55 cm in length—the same size or sl ...

, ''Corvus torquatus'' **** Piping crow, ''Corvus typicus'' **** Banggai crow, ''Corvus unicolor'' ***''Eurasian and North African'' species **** Hooded crow, ''Corvus cornix'' ***** Mesopotamian crow, ''Corvus (cornix) capellanus'' **** Carrion crow (western carrion crow), ''Corvus corone'' ***** Eastern carrion crow, ''Corvus (corone) orientalis'' **** Rook, ''Corvus frugilegus'' ****

Western jackdaw The western jackdaw (''Coloeus monedula''), also known as the Eurasian jackdaw, the European jackdaw, or simply the jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa; it is mostly resident, a ...

, ''Corvus monedula'' **** Fan-tailed raven, ''Corvus rhipidurus'' **** Brown-necked raven, ''Corvus ruficollis'' ***''Holarctic'' species ****

Common raven The common raven (''Corvus corax'') is a large all-black passerine bird. It is the most widely distributed of all corvids, found across the Northern Hemisphere. It is a raven known by many names at the subspecies level; there are at least ...

, ''Corvus corax'' (see also next section) *****

Pied raven The pied raven (''Corvus corax varius'' morpha ''leucophaeus'') is an extinct colour morph of the North Atlantic subspecies of the common raven which was only found on the Faroe Islands and was last seen in 1902. It had large areas of white feath ...

, ''Corvus corax varius'' morpha ''leucophaeus'' (an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

color variant) ***''North and Central American'' species ****

, ''Corvus brachyrhynchos'' ***** Northwestern crow, ''Corvus brachyrhynchos caurinus'' ****

Chihuahuan raven The Chihuahuan raven (''Corvus cryptoleucus'') is a species of crow in the family Corvidae that is native to the United States and Mexico. Description The proportions resemble the common raven with a heavy bill, but is about the same size as a c ...

, ''Corvus cryptoleucus'' **** Tamaulipas crow, ''Corvus imparatus'' **** Jamaican crow, ''Corvus jamaicensis'' **** White-necked crow, ''Corvus leucognaphalus'' ****

Cuban crow The Cuban crow (''Corvus nasicus'') is one of four species of crow that occur on islands in the Caribbean. It is closely related to the white-necked crow (''C. leucognaphalus'') and Jamaican crow (''C. jamaicensis''), with which it shares simil ...

, ''Corvus nasicus'' ****

Fish crow The fish crow (''Corvus ossifragus'') is a species of crow associated with wetland habitats in the eastern and southeastern United States. Taxonomy and etymology The fish crow was given its binomial name by the Scottish ornithologist Alexan ...

, ''Corvus ossifragus'' ****

Palm crow The palm crow (''Corvus palmarum'') is a relatively small corvid that occurs on the Caribbean island of Hispaniola ( Haiti and the Dominican Republic) and Cuba, where it was formerly very frequent, but is now reduced in population. Taxonomy T ...

, ''Corvus palmarum'' ****

Sinaloa crow The Sinaloa crow (''Corvus sinaloae'') is a crow native to western Mexico. Description Visually, it is nearly identical to and the same length (34–38 cm) as the Tamaulipas crow (''Corvus imparatus''). It has the same purple-glossed, silky ...

, ''Corvus sinaloae'' ****

Western raven The common raven (''Corvus corax'') is a large all-black passerine bird. It is the most widely distributed of all corvids, found across the Northern Hemisphere. It is a raven known by many names at the subspecies level; there are at least e ...

, ''Corvus (corax) sinuatus'' ***''Tropical African'' species **** White-necked raven, ''Corvus albicollis'' **** Pied crow, ''Corvus albus'' **** Cape crow, ''Corvus capensis'' **** Thick-billed raven, ''Corvus crassirostris'' **** Somali crow (dwarf raven), ''Corvus edithae'' *Boreal jays **Genus '' Perisoreus'' ***

Canada jay The Canada jay (''Perisoreus canadensis''), also known as the gray jay, grey jay, camp robber, or whisky jack, is a passerine bird of the family Corvidae. It is found in boreal forests of North America north to the tree line, and in the Ro ...

, ''Perisoreus canadensis'' *** Siberian jay, ''Perisoreus infaustus'' *** Sichuan jay, ''Perisoreus internigrans'' *New World jays **Genus '' Aphelocoma'' – scrub-jays ***

, ''Aphelocoma californica'' *** Island scrub jay, ''Aphelocoma insularis'' *** Woodhouse's scrub jay, ''Aphelocoma woodhouseii'' ***

, ''Aphelocoma coerulescens'' ***

Mexican jay The Mexican jay (''Aphelocoma wollweberi'') Etymology: ''Aphelocoma'', from Latinized Ancient Greek ''apheles-'' (from ἀφελής-) "simple" + Latin ''coma'' (from Greek ''kome'' κόμη) "hair", in reference to the lack of striped or banded ...

, ''Aphelocoma wollweberi'' *** Transvolcanic jay, ''Aphelocoma ultramarina'' ***

Unicolored jay The unicolored jay (''Aphelocoma unicolor'') Etymology: ''Aphelocoma'', from Latinized Ancient Greek ''apheles-'' (from ἀφελής-) "simple" + Latin ''coma'' (from Greek ''kome'' κόμη) "hair", in reference to the lack of striped or banded ...

, ''Aphelocoma unicolor'' **Genus '' Calocitta'' – magpie-jays *** Black-throated magpie-jay, ''Calocitta colliei'' *** White-throated magpie-jay, ''Calocitta formosa'' **Genus '' Cyanocitta'' ***

, ''Cyanocitta cristata'' ***

, ''Cyanocitta stelleri'' **Genus '' Cyanocorax'' *** Black-chested jay, ''Cyanocorax affinis'' *** Purplish-backed jay, ''Cyanocorax beecheii'' *** Azure jay, ''Cyanocorax caeruleus'' *** Cayenne jay, ''Cyanocorax cayanus'' *** Plush-crested jay, ''Cyanocorax chrysops'' *** Curl-crested jay, ''Cyanocorax cristatellus'' *** Purplish jay, ''Cyanocorax cyanomelas'' *** White-naped jay, ''Cyanocorax cyanopogon'' *** Tufted jay, ''Cyanocorax dickeyi'' *** Azure-naped jay, ''Cyanocorax heilprini'' *** Bushy-crested jay, ''Cyanocorax melanocyaneus'' *** White-tailed jay, ''Cyanocorax mystacalis'' *** San Blas jay, ''Cyanocorax sanblasianus'' *** Violaceous jay, ''Cyanocorax violaceus'' *** Green jay, ''Cyanocorax luxuosus'' *** Inca jay, ''Cyanocorax yncas'' *** Yucatan jay, ''Cyanocorax yucatanicus'' **Genus '' Psilorhinus'' *** Brown jay, ''Psilorhinus morio'' **Genus '' Cyanolyca'' *** Silvery-throated jay, ''Cyanolyca argentigula'' *** Black-collared jay, ''Cyanolyca armillata'' *** Azure-hooded jay, ''Cyanolyca cucullata'' ***

White-throated jay The white-throated jay (''Cyanolyca mirabilis''), also known as the Omiltemi jay, is a species of bird in the family Corvidae. It is endemic to the Sierra Madre del Sur ranges of Mexico. Its natural habitat is subtropical or tropical moist mont ...

, ''Cyanolyca mirabilis'' *** Dwarf jay, ''Cyanolyca nana'' *** Beautiful jay, ''Cyanolyca pulchra'' *** Black-throated jay, ''Cyanolyca pumilo'' *** Turquoise jay, ''Cyanolyca turcosa'' *** White-collared jay, ''Cyanolyca viridicyana'' **Genus '' Gymnorhinus'' *** Pinyon jay, ''Gymnorhinus cyanocephalus''

Explanatory notes

References

External links

Corvidae videos
on the Internet Bird Collection
corvids.de – Corvids-Literature-Database

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

Talking Eurasian magpie ''Pica pica''

Rare crow shows a talent for tool use
{{authority control Bird families Extant Miocene first appearances

Systematics, taxonomy, and evolution

Fossil record

Ecology

Behaviour

Food and feeding

Reproduction

Intelligence

Empathy-consolation

Empathy-emotional contagion

Interspecific communications

Personality conformity

Social construction

Social complexity

Consciousness, culture-rudiments, and neurology

Tool use, memory, and complex rational thought

Implications and specific comparisons with other animals

Disease

Relationship with humans

Role in myth and culture

Status and conservation

Species

Explanatory notes

References

Further reading

External links