Corvidae
Common Raven
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Order: Passeriformes Family: Corvidae Vigors, 1825
Genera
many, see article text Wikipedia does not have an article with this exact name. ... Binomial name Corvus corax Linnaeus, 1758 Common Raven range Subspecies The Common Raven (Corvus corax), also known as the Northern Raven, is a large all-black passerine bird in the crow family, with iridescent feathers. ... Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. ... Animalia redirects here. ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... “Aves” redirects here. ... Families Many, see text A passerine is a bird of the giant order Passeriformes. ... Nicholas Aylward Vigors (1785 – October 26, 1840) was an Irish zoologist and politician. ...

Corvidae is a family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies and nutcrackers (Clayton and Emery 2005, [1]). Collectively its members are called corvids and there are over 120 species. In biological classification, family (Latin: familia, plural familiae) is 1) a rank or 2) a taxon in that rank. ... Families Many, see text This is for the bird. ... Families Many, see text A passerine is a bird of the giant order Passeriformes. ... “Aves” redirects here. ... Species See text. ... Species See text. ... Binomial name Corvus frugilegus Linnaeus, 1758 Rook range The Rook, Corvus frugilegus, is a member of the passerine order of birds and the crow family. ... Binomial name Corvus monedula (Linnaeus, 1758) Jackdaw range The Jackdaw (Corvus monedula) is one of the smallest species (34–39 cm in length) in the genus of crows and ravens. ... Genera Garrulus Podoces Ptilostomus Perisoreus Aphelocoma Gymnorhinus Cyanocitta Calocitta Cyanocorax Cyanolyca The jays are several species of medium-sized, usually colorful and noisy passerine birds in the crow family Corvidae. ... Genera Pica Urocissa Cissa Cyanopica The magpies are medium to large, often colorful and noisy passerine birds of the crow family, Corvidae. ... Genera Dendrocitta Crypsirina Temnurus The treepies comprise three closely related genera (Dendrocitta, Crypsirina, Temnurus) of long-tailed passerine birds in the family Corvidae. ... Species Nucifraga caryocatactes Nucifraga columbiana The nutcrackers (Nucifraga) are a genus of two species of passerine bird, in the family Corvidae, related to the jays and crows. ...

They are medium to large birds with strong feet and bills, rictal bristles and a single moult each year (most passerines moult twice). In animals, moulting (Commonwealth English) or molting (American English) is the routine shedding off old feathers in birds, or of old skin in reptiles, or of old hairs in mammals (see also coat (dog)). In arthropods, such as insects, arachnids and crustaceans, moulting describes the shedding of its exoskeleton (which...

Corvids are found worldwide except for the tip of South America and the polar ice caps (Clayton and Emery 2005). Recently the Corvus genus has re-entered Australia, resulting in five new species and one new subspecies (see crows). 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 South America South America is a continent crossed by the equator, with most of its area in the Southern Hemisphere. ... Species See text. ... Map of Central America Central America is the central geographic region of the Americas. ... World map showing the location of Asia. ... Eurasia African-Eurasian aspect of Earth Eurasia is the Earths largest landmass covering about 21215121321km² compared with the Americas (approximately 42,000,000 km²), Africa (approximately 30,000,000 km²), and Antarctica (approximately 13,000,000 km²). Eurasia comprises the traditional continents of Europe and Asia. ... A world map showing the continent of Africa Africa is the worlds second-largest and second most-populous continent, after Asia. ... Australasia Australasia is a term variably used to describe a region of Oceania: Australia, New Zealand, and neighbouring islands in the Pacific Ocean. ... World map showing North America A satellite composite image of North America. ...

Systematics, taxonomy and evolution

The earliest corvid fossils date to the mid-Miocene (about 17 MYA) [2]. The genus Corvus, including the crows and ravens, makes up over a third of the entire family. The name Corvus is onomatopoetic, and refers to their raucous “croaking” calls [3]. Corvids are derived from Australasian ancestors and from there, spread throughout the world. Other lineages derived from these ancestors evolved into ecologically diverse, but often Australasian groups. Over the years there has been much disagreement on the exact evolutionary relationships of the corvid family and their relatives. Sibley and Ahlquist have united the corvids with other taxa in the Corvida, but current research favors the theory that this grouping is partly artificial. The Miocene Epoch is a period of time that extends from about 23. ... In astronomy, geology, and paleontology, mya is an acronym for million years ago and is used as a unit of time to denote length of time before the present. ... The sound of hitting a ball can be described as Whack. In rhetoric, linguistics and poetry, onomatopoeia is a figure of speech that employs a word, or occasionally, a grouping of words, that imitates, echoes, or suggests the object it is describing, such as bang, click, fizz, hush or buzz... Australasia Australasia is a term variably used to describe a region of Oceania: Australia, New Zealand, and neighbouring islands in the Pacific Ocean. ... The Sibley-Ahlquist taxonomy is a radical bird taxonomy based on DNA-DNA hybridization studies conducted in the late 1970s and throughout the 1980s. ... Families Many, see text Corvida is under the Sibley-Ahlquist taxonomy, one of two parvorders contained within the suborder Passeri. ...

Clarification of the interrelationships of the corvids has been researched by Ericson et al. (2005), based on comparison of several DNA sequences. The Crested Jay (Platylophus galericulatus) is traditionally included in the Corvidae, but seems not to be a member of this family^{[citation needed]}. Likewise, the Hume's Ground "Jay" (Pseudopodoces humilis) is in fact a member of the family (Paridae) (titmice)^{[citation needed]}. 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, which are not closely related inter se. The position of the Azure-winged Magpie, which has always been a major enigma, is even more unclear than it was before. part of a DNA sequence A DNA sequence (sometimes genetic sequence) is a succession of letters representing the primary structure of a real or hypothetical DNA molecule or strand, The possible letters are A, C, G, and T, representing the four nucleotide subunits of a DNA strand (adenine, cytosine, guanine... Binomial name Pseudopodoces humilis (Hume, 1871) Humes Ground Tit (Pseudopodoces humilis), previously known as Humes Ground Jay, is a lark-like bird. ... Genera see text The tits, chickadees, and titmice, family Paridae, are a large family of small passerine birds which occur in the northern hemisphere and Africa. ... In phylogenetics, a group is monophyletic (Greek: of one stem) if all organisms in that group are known to have developed from a common ancestral form, and all descendants of that form are included in the group. ... The Old World consists of those parts of Earth known to Europeans, Asians, and Africans before the voyages of Christopher Columbus; it includes Europe, Asia, and Africa (collectively known as Africa-Eurasia), plus surrounding islands. ... The Holarctic is a term used by zoologists to define the ecozone covering much of Eurasia and North America, which have often been connected by the Bering land bridge. ... Species Cyanopica cyana Pallas, 1776 Cyanopica (cyana) cooki Bonaparte, 1850 The Azure-winged Magpie (Cyanopica cyana) is a bird in the crow family. ...

• Choughs
  • Pyrrhocorax (2 species)

• Treepies
  • Dendrocitta (7 species)
  • Crypsirina (2 species)
  • Temnurus - Ratchet-tailed Treepie
  • Platysmurus - Black Magpie

• Oriental Magpies
  • Urocissa (5 species)
  • Cissa (3 species)

• Old World and Ground Jays
  • Garrulus (3 species)
  • Podoces (4 species)
  • Ptilostomus - Piapiac

• Stresemann's Bush Crow, Zavattariornis stresemanni

• Nutcrackers
  • Nucifraga (1-3 species)

• Holarctic Magpies
  • Pica (1-6 species)

• Crows and Ravens
  • Corvus (some 43-45 species, 1 possibly recently extinct, 1 extinct in the wild)

• Azure-winged Magpie, Cyanopica cyana (possibly 2 species)

• Grey Jays
  • Perisoreus (3 species)

• New World Jays
  • Aphelocoma - scrub-jays (5-6 species)
  • Calocitta - magpie-jays (2 species)
  • Cyanocitta(2 species)
  • Cyanocorax (17 species)
  • Cyanolyca (9 species)
  • Gymnorhinus - Pinyon Jay

• Prehistoric corvid genera (probably mainly New World and Old World Jays and Holarctic Magpies)
  • Miocitta
  • Miocorvus
  • Henocitta (Arredondo Early Pleistocene of Williston, USA)
  • Protocitta (Early Pleistocene of Reddick, USA)
  • Corvidae gen. et sp. indet. (Sicily) - probably belongs into extant genus.

In addition, there are numerous fossil species of extant genera (mainly European Corvus). See the genus accounts for more. Pyrrhocorax is the name of a genus of black European birds in the Corvidae (crow) family. ... Genera Dendrocitta Crypsirina Temnurus The treepies comprise three closely related genera (Dendrocitta, Crypsirina, Temnurus) of long-tailed passerine birds in the family Corvidae. ... Genera Dendrocitta Crypsirina Temnurus The treepies comprise three closely related genera (Dendrocitta, Crypsirina, Temnurus) of long-tailed passerine birds in the family Corvidae. ... The Old World genus Crypsirina is a small genus of passerine birds in the Corvidae. ... Genera Pica Urocissa Cissa Cyanopica The magpies are medium to large, often colorful and noisy passerine birds of the crow family, Corvidae. ... Species Urocissa is a genus of birds in the huge Passerine order in the family Corvidae. ... Genus Cissa Boie, 1826 Cissa is a genus of short-tailed magpies that reside in the forests of tropical and sub_tropical Asia. ... Species Podoces biddulphi Podoces hendersoni Podoces panderi Podoces pleskei The ground jays or ground choughs belong to a very distinct and interesting group of the passerine order of birds in the genus Podoces of the crow family corvidae that inhabit high altitude semi-desert areas from central Asia to Mongolia. ... Species Garrulus glandarius Garrulus lanceolatus Garrulus lidthi The genus Garrulus contains the Old World jays, passerine birds of the family Corvidae, and numbers only three species. ... Species Podoces biddulphi Podoces hendersoni Podoces panderi Podoces pleskei The ground jays or ground choughs belong to a very distinct and interesting group of the passerine order of birds in the genus Podoces of the crow family corvidae that inhabit high altitude semi-desert areas from central Asia to Mongolia. ... Binomial name Ptilostomus afer (Linnaeus, 1766) The Piapiac (Ptilostomus afer) is a member of the crow family, and is the only member of the genus Ptilostomus (Swainson, 1837). ... Binomial name Zavattariornis stresemanni Moltoni, 1938 The Stresemanns Bush Crow or occasionally called a Zavattariornis, is a rather Starling-like member of the Crow family, Corvidae. ... Species Nucifraga caryocatactes Nucifraga columbiana The nutcrackers (Nucifraga) are a genus of two species of passerine bird, in the family Corvidae, related to the jays and crows. ... Genera Pica Urocissa Cissa Cyanopica The magpies are medium to large, often colorful and noisy passerine birds of the crow family, Corvidae. ... A genus of three species of Magpie in the family Corvidae in both the New World and the old. ... For other uses of the word Crow, please see Crow (disambiguation). ... Species See text. ... For other uses of the word Crow, please see Crow (disambiguation). ... In biology and ecology, extinction is the ceasing of existence of a species or group of species. ... The Dodo, shown here in illustration, is an often-cited[1] example of extinction. ... Species Cyanopica cyana Pallas, 1776 Cyanopica (cyana) cooki Bonaparte, 1850 The Azure-winged Magpie (Cyanopica cyana) is a bird in the crow family. ... Genera Garrulus Podoces Ptilostomus Perisoreus Aphelocoma Gymnorhinus Cyanocitta Calocitta Cyanocorax Cyanolyca The jays are several species of medium-sized, usually colorful and noisy passerine birds in the crow family Corvidae. ... The genus Perisoreus is a very small genus of Jays from the Boreal regions of North America and Eurasia from Scandinavia to the Asian seaboard. ... Genera Garrulus Podoces Ptilostomus Perisoreus Aphelocoma Gymnorhinus Cyanocitta Calocitta Cyanocorax Cyanolyca The jays are several species of medium-sized, usually colorful and noisy passerine birds in the crow family Corvidae. ... Species Aphelocoma californica – Western Scrub Jay Aphelocoma coerulescens – Florida Scrub Jay Aphelocoma insularis – Island Scrub Jay Aphelocoma ultramarina – Mexican Jay Aphelocoma unicolor – Unicolored Jay The scrub jays are passerine birds of the genus Aphelocoma. ... Genus Cyanocitta The genus Cyanocitta is a New World genus of jays, passerine birds of the family Corvidae. ... Species 17 species; see text. ... Cyanolyca is a genus of New World jays including: Cyanolyca armillata Black-collared Jay Cyanolyca turcosa Turquoise Jay Cyanolyca viridicyana White-collared Jay Cyanolyca cucullata Azure-hooded Jay Cyanolyca pulchra Beautiful Jay Cyanolyca pumilo Black-throated Jay Cyanolyca nana Dwarf Jay Cyanolyca mirabilis White-throated Jay Cyanolyca argentigula Silvery-throated... The genus Gymnorhinus is a Passerine bird in the family Corvidae and contains the single species below. ...

Typical size and appearance

Corvids have feathered, rounded nostrils, strong tails and wings, and similar sexes. Many corvids of temperate zones are mainly black or blue; however, some are pied black and white, some have a blue-purple iridescence and many tropical species are highly coloured. Corvids have strong, stout bills and large wingspans. The larger species are the largest members of the passerine order. Families Many, see text A passerine is a bird of the giant order Passeriformes. ...

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). Binomial name Corvus corax Linnaeus, 1758 Common Raven range Subspecies The Common Raven (Corvus corax), also known as the Northern Raven, is a large all-black passerine bird in the crow family, with iridescent feathers. ... Binomial name Corvus crassirostris Rüppell, 1836 The Thick-billed Raven (Corvus crassirostris), a Corvid from the Horn of Africa, shares with the Common Raven the accolade of the largest in the family (60-64 cm in length) and indeed the largest of the bird order Passeriformes (perching birds). ...

Species can be identified based on size, shape, and geography; however, some, especially the Australian crows, are best identified by their raucous calls. [4]

Social interaction

Some corvids have strong organization and community groups. Jackdaws, for example, have a strong social hierarchy, and are facultatively colonial during breeding (Verhulst and Salomons 2004). Providing mutual aid has also been recorded within many of the corvid species. [5]

Young corvids have been known to play and take part in elaborate social games. The games resemble “king of the mountain” and “follow the leader.” Other games involve 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 (Gill 2003).

Some corvids can be aggressive. Blue Jays, 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 the crow to steal food.[6] Binomial name Cyanocitta cristata Linnaeus, 1758 Blue Jay range The Blue Jay (Cyanocitta cristata) is a North American jay, a handsome bird with predominantly lavender-blue to mid-blue feathering from the top of the head to midway down the back. ...

Food and foraging habits

The natural diet of many corvid species is omnivorous, consisting of invertebrates, 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 Crows, Common Ravens and Steller's Jays 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. (Marzluff and Neatherlin 2006). Invertebrate is a term that describes any animal without a spinal column. ... An American Black Vulture feeding on squirrel carrion For other uses, see Carrion (disambiguation). ... Binomial name Corvus brachyrhynchos Brehm, 1822 American Crow range The American Crow (Corvus brachyrhynchos) is slightly smaller than the European Carrion Crow in overall size (39-49 cm in length) and also has a proportionately smaller bill. ... Binomial name Corvus corax Linnaeus, 1758 Common Raven range Subspecies The Common Raven (Corvus corax), also known as the Northern Raven, is a large all-black passerine bird in the crow family, with iridescent feathers. ... Binomial name Cyanocitta stelleri (Gmelin, 1788) The Stellers Jay (Cyanocitta stelleri) is a jay of western North America, closely related to the Blue Jay found in the rest of the continent, but having a black head and upper body. ...

Some corvids are predators of other birds. During the wintering months, corvids typically form foraging flocks [7]. However, some crows also eat many agricultural pests including cutworms, wireworms, grasshoppers and harmful weeds [8]. Some corvid will eat carrion, and since they lack a specialized beak for tearing into flesh, they must wait until animals are opened by other predators or as roadkill.

Migration

Corvids occur in most climatic zones. Most are sedentary and do not migrate significantly. However, during a shortage of food, eruptive migration can occur [9]. When species are migratory, they will form large flocks in the fall (around August) and travel south [10]. Flock of Barnacle Geese during autumn migration Many species of birds undertake seasonal journeys of various lengths, a phenomenon known as Bird migration. ...

Reproduction

Some corvids are well known communal roosters. Some groups of roosting corvids have been as large as 2,000 birds (Everding and Jones 2006). 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 [11]. 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. As expected, corvids provide biparental care.

Sexual selection is also quite complex in the Corvidae family. Young corvid members undergo a series of tests, including aerobatic feats, before being accepted as a mate by the opposite sex [12].

Unlike most other species, corvid fitness and reproduction, especially with the crows, has increased due to human development. The survival and reproductive success of crows and ravens, according to Marzluff and Neatherlin’s 2006 study, was positively associated with their intimacy of human populations.

Human development provides additional resources by clearing land, creating shrublands rich in berries and insects. When the cleared land naturally replenishes, the young dense trees are used by jays and crows for nesting sites. Ravens typically use larger trees in denser forests (Marzluff and Neatherlin 2006).

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 the overlap of ravens. This invasion of breeding ranges allowed a related increase in local density (Marzluff and Neatherlin 2006). In the US the American Crow population has definitely grown over the years. It is possible, that the American Crow, due to humans increasing suitable habitat, will drive out the Northwestern and Fish Crows (Marzluff and Angell 2005). Binomial name Corvus brachyrhynchos Brehm, 1822 American Crow range The American Crow (Corvus brachyrhynchos) is slightly smaller than the European Carrion Crow in overall size (39-49 cm in length) and also has a proportionately smaller bill. ... Binomial name Corvus brachyrhynchos Brehm, 1822 American Crow range The American Crow (Corvus brachyrhynchos) is slightly smaller than the European Carrion Crow in overall size (39-49 cm in length) and also has a proportionately smaller bill. ... Binomial name Corvus caurinus Baird, 1858 The Northwestern Crow (Corvus caurinus) is very similar to the more western forms of the American Crow (Corvus brachyrhynchos) but it is slightly smaller (33-41 cm in length) and has proportinately smaller feet with a slightly more slender bill. ... Binomial name Corvus ossifragus Wilson, 1812 The Fish Crow (Corvus ossifragus) is superficially very similar to the American Crow but is smaller (36-41 cm in length) and has a more silky smooth plumage by comparison. ...

Jackdaws can breed in buildings or in rabbit warrens (Verhulst and Salomons 2004). White-throated Magpie-jays are cooperatively breeding corvids where the helpers are mostly female. Cooperative breeding takes place when additional adults help raise the nestlings. These adults are often called “helpers” and in most cooperatively breeding birds the males take on the “helper” role while females join other groups (Berg 2005). Binomial name Calocitta formosa Swainson, 1827 The White-throated Magpie-Jay, Calocitta formosa is a large Central American jay species. ... Cooperative breeding is a social system in which individuals help care for young that are not their own. ... Helpers at the nest is a term used in behavioural ecology and evolutionary biology to describe a social structure in which juveniles, of one or both sexes, remain in association with their parents and help them in raising subsequent broods or litters, instead of dispersing and beginning to reproduce themselves. ...

Nest predation

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, the Steller’s Jays, which were successful independent of human development, were the more frequent nest predator. Therefore, the human relationship with crows and ravens did not increase nest predation since jays accounted for the most nest predation by corvids (Marzluff and Neatherlin 2006).

Myths

Since some corvids, especially in the temperate Northern Hemisphere, have black feathers and eat carrion, humans have long associated members of Corvidae with death and extreme injustice (Marzluff and Angell 2005). Throughout history, corvids have been perceived as dark messengers, bearing ill will and other demonic associations. This dark connection is reflected by the literary terms coined to describe groups of crows (a murder), ravens (unkindness, constable or conspiracy), and jays (scold). [13].

Despite the well-known demonic association, folklore also represents corvids as wise animals. Native Americans believed that a raven created the earth, the Norse god Odin constantly sought the advice of ravens, and even Aesop featured corvids as smart heroes in many fables (Clayton and Emery 2005). According to Native American cultures, despite being a trickster spirit, ravens were popular on totems, were credited with creating man and were responsible for placing the Sun in the sky. In western literature, popularized by E.A. Poe, the Common Raven was a symbol of darkness, depression and death. However, in mediaeval times the raven stood for virility. Legends report that a raven’s favourite food is dead animals, and that they sometimes hunt with wolves [14]. For more myths and legends see crow and raven pages. Binomial name Corvus corax Linnaeus, 1758 Common Raven range Subspecies The Common Raven (Corvus corax), also known as the Northern Raven, is a large all-black passerine bird in the crow family, with iridescent feathers. ... Species See text. ... Species See text. ...

Corvid intelligence

Based on a brain-to-body ratio, the corvid brain is the largest of any bird, equals that of a chimpanzee, is roughly the same as a dolphin, and is only slightly lower than a human [15]. Their intelligence is evident due to the long developmental 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 (Clayton and Emery 2005). When compared to carnivorous mammals (specifically dogs and cats) in one laboratory test, corvid birds outshone their opponents (Krushinskii et al 1979). Dr. Louis Lefebvre’s avian IQ test declared Corvidae the most intelligent bird based on the scale [16]. Another recent study suggests, "their cognitive abilities are a match for primates such as great apes." While the study notes that their brain is structured differently they have the ability to make geometrical measurements. Some Corvids demonstrate the capacity for imagination, something that only humans were thought to posess. For example, they remember the previous relevant social context, use their own experience of having been a thief to predict the behavior of a pilferer, and determined the safest course to protect the caches from pilferage. Studies to assess like cognitive abilities in apes have been inconclusive. [17]

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, dominance, and be able to update the information constantly. Therefore, social complexity directly corresponds to high cognition (Bond et al 2003).

There are also specific examples of corvid cleverness. One 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.[18] A group of crows in England took turns lifting garbage bin lids while their companions collected food.^{[citation needed]} Binomial name Corvus corone Linnaeus, 1758 Carrion Crow range The Carrion Crow, Corvus corone, can be distinguished from the Raven by its size (48–52 cm in length) and from the Hooded Crow by its black plumage, but there is frequent confusion between it and the Rook. ...

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. 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 is compared to human episodic memory, which was previously thought unique to humans (Clayton and Emery 2005). Binomial name Aphelocoma californica (Vigors, 1839) Subspecies 14 (7+7) - see text The Western Scrub-jay (Aphelocoma californica[1]), also known as California Jay or Long-tailed Jay (and see below) is a species of scrub-jay native to western North America, ranging from southern Washington to central Texas and...

Looking at the act of thievery in the corvid family, it has been suggested that birds will take their experience as a thief and use it to predict other bird actions of thievery. This explains why, if a corvid has committed thievery, they will take extra precautions (such as moving hiding places) to avoid being a future victim. Being able to predict others' behaviour based on one's own experiences is another trait previously thought unique to humans. Laboratory experiments have confirmed that crows in particular can sometimes use a past experience to approach a new obstacle (Clayton and Emery 2005).

New Caledonian Crows have been observed to make tools of twigs trimmed into hooks. They then use to hooks to pull insect larvae from tree holes. Other corvids that have been observed using tools include the American Crow, Blue Jay, and Green Jay. Diversity in tool design among corvids suggest cultural variation. Again, apes are the only other animals known to use tools in such a fashion (Clayton and Emery 2005). Nutcrackers and Jackdaws were compared in a 2002 study based on geometric rule learning. The corvids, along with a 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 (Jones et al 2002). Binomial name Corvus moneduloides Lesson, 1830 The New Caledonian Crow (Corvus moneduloides) is a moderately sized crow (40 cm in length) similar in size to the House Crow but less slender looking. ... Binomial name Corvus brachyrhynchos Brehm, 1822 American Crow range The American Crow (Corvus brachyrhynchos) is slightly smaller than the European Carrion Crow in overall size (39-49 cm in length) and also has a proportionately smaller bill. ... Binomial name Cyanocitta cristata Linnaeus, 1758 Blue Jay range The Blue Jay (Cyanocitta cristata) is a North American jay, a handsome bird with predominantly lavender-blue to mid-blue feathering from the top of the head to midway down the back. ... Binomial name Cyanocorax yncas (Boddaert, 1783) The Green Jay (Cyanocorax yncas) is a bird species with distinct regional forms within its large but discontinuous range. ... Species Nucifraga caryocatactes Nucifraga columbiana The nutcrackers (Nucifraga) are a genus of two species of passerine bird, in the family Corvidae, related to the jays and crows. ... Binomial name Corvus monedula (Linnaeus, 1758) Jackdaw range The Jackdaw (Corvus monedula) is one of the smallest species (34–39 cm in length) in the genus of crows and ravens. ...

A very popular crow scare tactic in the agricultural business is the scarecrow. However, due to the corvid’s 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 [19]. Recent taxonomy places corvids, based on their evolutionary progress, in the middle of the passerines, despite efforts to refer to to them as latest developing of the birds due to their intelligence [20]. As the researcher states, "During the 19th century there arose the belief that these were the “most advanced” birds, based upon the belief that Darwinian evolution brings “progress.” In such a classification (Corvids as) the “most intelligent” of birds were listed last reflecting their position “atop the pyramid.” Modern biologists reject the concept of hierarchical “progress” in evolution."

Threatened species

Despite the fact that most corvids are not threatened (but are most likely secured by human interaction) a few species are in danger. For example, the destruction of the Southeast Asian rainforests is endangering mixed-species feeding flocks with members from the family Corvidae (Lee et al 2005). Also, since scrub is an endangered ecosystem, the Florida Scrub-jays are threatened with extinction (Breiniger, et al 2006). A mixed-species feeding flock or mixed hunting party is a flock of birds of different species that join each other to search for food. ... Binomial name Aphelocoma coerulescens (Bosc, 1795) The Florida Scrub Jay (Aphelocoma coerulescens) is one of four species of scrub jay native to North America. ...

Songs/calls:

For all corvid calls.[21]

Citations

• Berg, Elena C. (2005): Parentage and reproductive success in the white-throated magpie-jay, Calocitta formosa, a cooperative breeder with female helpers. Animal Behavior 70(2): 375-385. DOI:10.1016/j.anbehav.2004.11.008 (HTML abstract)

• Breininger, D. R.; Toland, B.; Oddy, D. M. & Legare, M. L. (2006): Landcover characterizations and Florida scrub-jay (Aphelocoma coerulescens) population dynamics. Biological Conservation 128: 169-181. PDF fulltext

• Bond, Alan B.; Kamil, Alan C. & Balda, Russell P. (2003): Social complexity and transitive inference in corvids. Animal Behaviour 65(3): 479-487. DOI:10.1006/anbe.2003.2101 (HTML abstract)

• Clayton, Nicola & Emery, Nathan (2005): Corvid cognition. Current Biology 15(3): R80-R81. PDF fulltext

• Ericson, Per G. P.; Jansén, Anna-Lee; Johansson, Ulf S. & Ekman, Jan (2005): Inter-generic relationships of the crows, jays, magpies and allied groups (Aves: Corvidae) based on nucleotide sequence data. Journal of Avian Biology 36: 222-234. PDF fulltext

• Everding, Susanne E. & Jones, Darryl N. (2006): Communal roosting in a suburban population of Torresian crows (Corvus orru). Landscape and Urban Planning 74(1): 21-33. PDF fulltext

• Gill, F. B. (2003) Ornithology (2nd edition). W.H. Freeman and Company, New York. ISBN 0-7167-2415-4

• Jones, Juli E,; Antoniadis, Elena; Shettleworth, Sara J. & Kamil, Alan C. (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

• Krushinskii, L. V.; Zorina, Z. A. & Dashevskii, B. A. (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]

• Lee, T. M.; Soh, M. C. K.; Sodhi, N.; Koh, L. P. & Lim, S. L. H. (2005): Effects of habitat disturbance on mixed species bird flocks in a tropical sub-montane rainforest. Biological Conservation 122(2): 193-204. DOI:10.1016/j.biocon.2004.07.005 (HTML abstract)

• Marzluff, John M. & Angell, T. (2005): In the Company of Crows and Ravens. Yale University Press, New Haven, Connecticut. ISBN 0-300-10076-0

• Marzluff, John M. & Neatherlin, Eric (2006): Corvid response to human settlements and campgrounds: Causes, consequences, and challengers for conversation. Biological Conservation 130(2): 301-314. DOI:10.1016/j.biocon.2005.12.026 (HTML abstract)

• Verhulst, Sion & Salomons, H. Martijn (2004): Why fight? Socially dominant jackdaws, Corvus monedula, have low fitness. Animal Behaviour 68: 777-783. DOI:10.1016/j.anbehav.2003.12.020 (HTML abstract)

A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

External links

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