Corvus

Corvus is a widely distributed genus of medium-sized to large birds in the family Corvidae. The genus includes species commonly known as crows, ravens, rooks and jackdaws; there is no consistent distinction between "crows" and "ravens", and these appellations have been assigned to different species chiefly on the basis of their size, crows generally being smaller than ravens.

Ranging in size from the relatively small pigeon-sized jackdaws (Eurasian and Daurian) to the common raven of the Holarctic region and thick-billed raven of the highlands of Ethiopia, the 45 or so members of this genus occur on all temperate continents except South America, and several islands. The crow genus makes up a third of the species in the family Corvidae. The members appear to have evolved in Asia from the corvid stock, which had evolved in Australia. The collective name for a group of crows is a "flock" or a "murder".[1] The genus name is Latin for "raven".[2]

Recent research has found some crow species capable of not only tool use, but also tool construction.[3] Crows are now considered to be among the world's most intelligent animals[4] with an encephalization quotient equal to that of many non-human primates.[5]

Crow
Temporal range: 17–0 Ma
Middle Miocene – Recent
Corvus-brachyrhynchos-001
American crow (Corvus brachyrhynchos)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Corvidae
Subfamily: Corvinae
Genus: Corvus
Linnaeus, 1758
Species
many, see
Diversity
c. 45 species

Description

Flying Crow
Hooded crow (Corvus cornix) in flight
Raven scavenging on a dead shark
Jungle crow (Corvus macrorhynchos) scavenging on a dead shark at a beach in Kumamoto, Japan

Corvus species are all black or black with little white or grey plumage. They are stout with strong bills and legs. Sexual dimorphism is limited.

Evolutionary history and systematics

Crow on a branch
Rook (Corvus frugilegus) on a branch

The members of the genus Corvus are believed to have evolved in central Asia and radiated out into North America, Africa, Europe, and Australia.

The latest evidence[6] regarding the evolution indicates descent within the Australasian family Corvidae. However, the branch that would produce the modern groups such as jays, magpies, and large, predominantly black Corvus species had left Australasia and were concentrated in Asia by the time the Corvus species evolved. Corvus has since re-entered Australia (relatively recently) and produced five species with one recognized subspecies.

The genus was originally described by Linnaeus in his 18th-century work Systema Naturae.[7] The name is derived from the Latin corvus meaning "raven".[8]

The type species is the common raven (Corvus corax); others named in the same work include the carrion crow (C. corone), the hooded crow (C. cornix), the rook (C. frugilegus), and the jackdaw (C. monedula). The genus was originally broader, as the magpie was designated C. pica before being moved later into a genus of its own. At least 42 extant species are now considered to be in this genus, and at least 14 extinct species have been described.

The fossil record of crows is rather dense in Europe, but the relationships among most prehistoric species are not clear. Corvids are found in major cities across the world, and a major increase in the number of crows in urban settings has occurred since the 1900s. Historical records suggest that the population of American crows found in North America has been growing steadily since the introduction of European colonization, and spread east to west with the opening of the frontier. Crows were uncommon in the Pacific Northwest in the 1900s, except in riparian habitats. Populations in the west increased substantially from the late 1800s to mid 1900s. Crows and ravens spread along with agriculture and urbanization into the western part of North America.[9]

Species

Behavior

House crow Bangalore India wb
House crow (Corvus splendens), Bangalore

Communal roosting

Crows gather in large communal roosts numbering between 200 and tens of thousands of individuals during nonbreeding months, particularly in the winter. These gatherings tend to happen near large food sources such as garbage dumps and shopping centers. [10]

Play

Countless incidents are recorded of corvids at play. Many behaviourists see play as an essential quality in intelligent animals.[11]

Calls

Crows and the other members of the genus make a wide variety of calls or vocalizations.[12] Crows have also been observed to respond to calls of other species; presumably, this behavior is learned because it varies regionally.[13] Crows' vocalizations are complex and poorly understood. Some of the many vocalizations that crows make are a "koww", usually echoed back and forth between birds, a series of "kowws" in discrete units, a long caw followed by a series of short caws (usually made when a bird takes off from a perch), an echo-like "eh-aw" sound, and more. These vocalizations vary by species, and within each species they vary regionally. In many species, the pattern and number of the numerous vocalizations have been observed to change in response to events in the surroundings (e.g. arrival or departure of crows).

Indian Crow vs
Indian crow in Tamil Nadu

Intelligence

As a group, crows show remarkable examples of intelligence. Natural history books from the 18th century recount an often-repeated, but unproven anecdote of "counting crows" — specifically a crow whose ability to count to five (or four in some versions) is established through a logic trap set by a farmer.[14][15] Crows and ravens often score very highly on intelligence tests. Certain species top the avian IQ scale.[16] Wild hooded crows in Israel have learned to use bread crumbs for bait-fishing.[17] Crows engage in a kind of mid-air jousting, or air-"chicken" to establish pecking order. They have been found to engage in activities such as sports,[18] tool use, the ability to hide and store food across seasons, episodic-like memory, and the ability to use individual experience in predicting the behavior of environmental conspecifics.[19]

One species, the New Caledonian crow, has also been intensively studied recently because of its ability to manufacture and use tools in the day-to-day search for food. On 5 October 2007, researchers from the University of Oxford presented data acquired by mounting tiny video cameras on the tails of New Caledonian crows. They pluck, smooth, and bend twigs and grass stems to procure a variety of foodstuffs.[20][21] Crows in Queensland have learned how to eat the toxic cane toad by flipping the cane toad on its back and violently stabbing the throat where the skin is thinner, allowing the crow to access the nontoxic innards; their long beaks ensure that all of the innards can be removed.[22][23]

The jackdaw and the European magpie have been found to have a nidopallium about the same relative size as the functionally equivalent neocortex in chimpanzees and humans, and significantly larger than is found in the gibbon.[24]

Crows have demonstrated the ability to distinguish individual humans by recognizing facial features.[25] Evidence also suggests they are one of the few nonhuman animals, along with insects like bees or ants, capable of displacement (communication about things that are not immediately present, spatially or temporally).[26][27] Ravens have been observed to recruit other ravens to large feeding sites, such as to the carcass of an animal.

Diet

House Crow (Corvus splendens) in Shantinagar, Dhaka, Bangladesh, 17 March 2015
Corvus splendens or house crow resting in shadows on a rooftop with slaughterhouse refuse to eat

Crows are omnivorous, and their diet is very diverse. They will eat almost anything, including other birds, fruits, nuts, mollusks, earthworms, seeds, frogs, eggs, nestlings, mice, and carrion. The origin of placing scarecrows in grain fields resulted from the crow’s incessant damaging and scavenging, although crows assist farmers by eating insects otherwise attracted to their crops.[28]

Reproduction

Crow-nestlings
Nestlings, almost ready to fledge

Crows reach sexual maturity around the age of three years for females and five years for males. Clutch size is approximately three to nine eggs, and the nesting period lasts between 20 and 40 days. Crows often mate for life, and young from previous years often help nesting pairs protect a nest and feed nestlings. [29]

Crow corvus nest
A crow's nest is made of materials like twigs, electrical wires, metal strips, plastic pieces, and other small items.

Crow nestlings in urban areas face threats such as nest entanglement from anthropogenic nesting materials and stunted growth due to poor nutrition. [30] [31]

Lifespan and disease

Some crows may live to the age of 20, and the oldest known American crow in the wild was almost 30 years old.[32] The oldest documented captive crow died at age 59.[33]

The American crow is highly susceptible to the recently introduced North American strain of West Nile virus.[34] American crows typically die within one week of acquiring the disease and very few survive exposure.

Conservation status

Corvus hawaiiensis in grass
The Hawaiian crow or ʻalala (Corvus hawaiiensis) is nearly extinct; only a few dozen birds survive in captivity. It is listed as "extinct in the wild" by the United States Fish and Wildlife Service.

Two species of crow have been listed as endangered by the U.S. Fish and Wildlife Service: the Hawaiian crow and the Mariana crow.[35] The American crow, despite having its population reduced by 45% since 1999 by the West Nile virus, is considered a species of least concern.

Problems and methods of control

Intelligence and social structures make most crow species adaptable and opportunistic. Crows frequently cause damage to crops and property,[36] strew trash, and transfer disease. In densely populated areas around the world, corvids are generally regarded as nuisance animals.[37] Crows are protected in the U.S. under the federal Migratory Bird Treaty Act of 1918, but because of their perceived destructive nature, control of the species is allowed in certain areas. Because of their intelligence, control is often difficult or expensive. Methods for control include hunting, chemical immobilization, harassment and scare tactics, and trapping. Before any measure is used to confine, trap, kill, poison, immobilize, or alter the habits of any wild bird species, a person must check local, state, and federal regulations pertaining to such actions.

Hunting

American Crow skeleton
Skeleton of American crow (Corvus brachyrhychos) on display at Museum of Osteology

In the United States, hunting is allowed under state and federal regulation. Crow hunting is considered a sport in rural areas of the U.S. because the birds are not considered a tasty traditional game species. Some cultures do treat various corvid species as a food source.[38] Liability and possible danger to persons and property limit the use of hunting or shooting as control methods in urban areas. Crows' wariness and cunning make harvesting crows in sufficient numbers difficult.

Scare tactics

Scare tactics have been the most widely used aversion tactic for crows in areas frequented by humans and domestic animal species. This safe method does not require constant maintenance or manpower to operate or monitor. However, corvids quickly become habituated to most tactics such as blast cannons, predator decoys, and traditional scarecrows. Greater success has been achieved by adding sound and motion to predator decoys to mimic a distressed crow being caught by a predator such as an owl or hawk.[39] Work is currently being done which uses multiple aversion techniques in one area. The theory is that multiple techniques used together will confuse the crows, thereby lessening the probability of habituation to stimuli.

Trapping

Trapping is a rarely used technique in the U.S., but is being used with success in parts of Europe and Australia. The ladder-style trap (e.g., Australian Crow Trap or Modified Australian Crow Trap) seems to be the most effective in crow-trapping techniques. Ladder traps are constructed in such a way that unintentional catch of nontarget species is avoided. If a nontarget species is caught, it can be easily released without harm to the bird. The traps are cost-efficient because they are inexpensive and simple to construct, and require little manpower to monitor. The bait used in the traps can also be specific to corvids. Carrion, grains, unshelled raw peanuts, and shiny objects in the trap are effective baits. When removing crows from a ladder trap, one living crow is left as an extremely effective decoy for other crows. Trapping is considered the most humane method for crow removal because the crows can be relocated without harm or stress. However, most wild birds in general have a knack for returning to their home ranges.[40]

Other methods

Other methods have been used with little or limited success. Lasers have been used successfully to remove large flocks of birds from roost structures in urban areas, but success in keeping crows off roosts has been short-lived.[41] Homeowners can reduce the presence of crows by keeping trash stored in containers, feeding pets indoors, and hanging tin pie-pans or reflective gazing globes around garden areas.

As food

Crows were hunted for survival by Curonians, a Baltic tribe,[42] when common food was exhausted and the landscape changed so that farming was not as productive during the 18th and 19th centuries. Fishermen supplemented their diet by gathering coastal bird eggs and preserving crow meat by salting and smoking it. It became a traditional food for poor folk and is documented in a poem, "The Seasons" by K. Donelaitis. After the nonhunting policy was lifted by the Prussian government in 1721–24 and alternative food supplies increased, the practice was forgotten. The tradition re-emerged after World War I; in marketplaces, butchered crows which were sought after and bought by townsfolk were common. The hunted crows were not the local, but the migrating ones; each year during the spring and autumn, crows migrated via the Curonian Spit between Finland and the rest of Europe. In 1943, the government even issued a hunting quota for such activities. Crows were usually caught by attracting them with smoked fish or grains soaked in spirits and then collecting them with nets. It was a job for the elderly or young who were unable to go to sea to fish, and it was common to catch 150 to 200 birds during a hunting day.

Human interaction

The common raven and carrion crow have been blamed for killing weak lambs and are often seen eating freshly dead corpses probably killed by other means. The Australian raven has been documented chasing, attacking, and seriously injuring lambs.[43] Rooks have been blamed for eating grain in the UK and brown-necked ravens for raiding date crops in desert countries.[44]

Crows have been shown to have the ability to visually recognize individual humans and to transmit information about "bad" humans by squawking.[45] Crows appear to show appreciation to humans by presenting them with gifts.[46][47]

Cultural depictions

Brooklyn Museum - Crow on a Branch - Kawanabe Kyosai
Crow on a Branch - Kawanabe Kyosai (1831–1889)

In folklore and mythology

Corbeau branche Kyo
Crow on a branch, Maruyama Ōkyo (1733–1795)
Dhumavati
Dhumavati

In Ancient Greece and Rome, several myths about crows and jackdaws included:

  • An ancient Greek and Roman adage, told by Erasmus runs, "The swans will sing when the jackdaws are silent," meaning that educated or wise people will speak after the foolish become quiet.[48]
  • The Roman poet Ovid saw the crow as a harbinger of rain (Amores 2,6, 34).[49]
  • Pliny noted how the Thessalians, Illyrians, and Lemnians cherished jackdaws for destroying grasshoppers' eggs. The Veneti are fabled to have bribed the jackdaws to spare their crops.[50]
  • Ancient Greek authors tell how a jackdaw, being a social creature, may be caught with a dish of oil into which it falls while looking at its own reflection.[50]
  • In Greek legend, princess Arne was bribed with gold by King Minos of Crete and was punished for her avarice by being transformed into an equally avaricious jackdaw, which still seeks shiny things.[51]

In the Bible account at 1 Kings 17:6, ravens are credited with providing Elijah food.

In Australian Aboriginal mythology, Crow is a trickster, culture hero, and ancestral being. Legends relating to Crow have been observed in various Aboriginal language groups and cultures across Australia; these commonly include stories relating to Crow's role in the theft of fire, the origin of death, and the killing of Eagle's son.

Crows are mentioned often in Buddhism, especially Tibetan disciplines. The Dharmapala (protector of the Dharma) Mahakala is represented by a crow in one of his physical/earthly forms.

In the Chaldean myth, the Epic of Gilgamesh, Utnapishtim releases a dove and raven to find land; however, the dove merely circles and returns. Only then does Utnapishtim send forth the raven, which does not return, and Utnapishtim concludes the raven has found land.[52]

In Chinese mythology, the world originally had 10 suns either spiritually embodied as 10 crows and/or carried by 10 crows; when all 10 decided to rise at once, the effect was devastating to crops, so the gods sent their greatest archer Houyi, who shot down nine crows and spared only one.[53][54]

In Denmark, the night raven is considered an exorcised spirit. A hole in its left wing denotes where the stake used to exorcise it was driven into the earth. He who looks through the hole will become a night raven himself.[55]

In Hinduism, crows are thought of as carriers of information that give omens to people regarding their situations. For example, when a crow crows in front of a person's house, the resident is expected to have special visitors that day. Also, in Hindu literature, crows have great memories which they use to give information. Symbolism is associated with the crow in the Hindu faith. On a positive note, crows are often associated with worship of ancestors because they are believed to be embodying the souls of the recently deceased. However, many other associations with crows are seen in Hinduism. Crows are believed to be connected with both the gods and goddesses, particularly the controversial ones such as Sani, the god of the planet Saturn, who uses a crow as his vehicle. In Hindu astrology, it is said that one who has the effect of Sani in their horoscope are angered easily, and may be unable to take control of their futures, but are extremely intelligent at the same time. Thus the presence of a crow, the vehicle of Sani is believed to have similar effects on the homes it lays its eyes on. Whether these effects are positive or negative is a source of debate in Hinduism.[56] Crows are also considered ancestors in Hinduism and during Śrāddha, the practice of offering food or pinda to crows is still in vogue.[57] Crows are associated with Dhumavati the form of mother goddess that invokes quarrel and fear.[58] Crows are also fed during the fifteen day period of Pitru Paksha, which occurs in the Autumn season, as an offering and sacrifice to the ancestors. During the time of Pitra Paksha, it is believed that the ancestors descend on earth from pitra-loka, and are able to eat food offered to them by the means of a crow. This can also occur during the time of Kumbha, many Hindus prepare entire vegetarian meals that are eaten solely by the crows and other birds.

In Irish mythology, crows are associated with Morrigan, the goddess of war and death.[59]

In Islam, according to a narration in the Hadith, the crow is one of the five animals for which no blame is placed on the one who kills them.[60] The Surat Al-Ma'ida describes the story of how the crow teaches son of Adam to cover dead body of his brother "Then Allah sent a crow digging up the earth so that he might show him how he should cover the dead body of his brother. He said: Woe me! do I lack the strength that I should be like this crow and cover the dead body of my brother? So he became of those who regret.".[61]

In Japanese mythology, a three-legged crow called Yatagarasu (八咫烏, "eight-hand-crow")[62] is depicted.[63]

In Korean mythology, a three-legged crow is known as Samjokgo (hangul: 삼족오; hanja: 三足烏).

In Norse mythology, Huginn and Muninn are a pair of common ravens that range the entire world, Midgard, bringing the god Odin information.

In Sweden, ravens are held to be the ghosts of murdered men.[64]

In Welsh mythology, the god Brân the Blessed – whose name means "crow" or "raven" — is associated with corvids and death; tradition holds that Bran's severed head is buried under the Tower of London, facing France — a possible genesis for the practice of keeping ravens in the Tower, said to protect the fortunes of Britain. In Cornish folklore, crows — magpies particularly — are associated with death and the "other world", and must be greeted respectfully. The origin of "counting crows" as augury is British; however, the British version rather is to "count magpies" — their black and white pied colouring alluding to the realms of the living and dead.

In some Native American mythologies, especially those in the Pacific Northwest, the raven is seen as both the Creator of the World and, separately, a trickster god.

In medieval times, crows were thought to live abnormally long lives. They were also thought to be monogamous throughout their long lives. They were thought to predict the future, to predict rain and reveal ambushes. Crows were also thought to lead flocks of storks while they crossed the sea to Asia.[65]

In popular culture

Literature

  • In Aesop's Fables, the jackdaw embodies stupidity in one tale (by starving while waiting for figs on a fig tree to ripen), vanity in another (the jackdaw sought to become king of the birds with borrowed feathers, but was shamed when they fell off),[66] and cunning in yet another (the crow comes up to a pitcher and knows that his beak is too short to reach the water, and if he tips it over, all the water will fall out, so the crow places pebbles in the pitcher so the water rises and he can reach it to relieve his thirst).[67]
  • The British Poet Laureate Ted Hughes combined some of the Amerindian and Celtic myths mentioned above in writing the 1970 poetry collection Crow: From the Life and Songs of the Crow (1970).
  • In Ovid's Metamorphoses, in Greek mythology, the god Apollo became enraged when the crow exposed his lover Coronis' tryst with a mortal, his ire transmuting the crow's feathers from white to black.[68]
  • In the Story of Bhusunda, a chapter of the Yoga Vasistha, a very old sage in the form of a crow, Bhusunda, recalls a succession of epochs in the earth's history, as described in Hindu cosmology. He survived several destructions, living on a wish-fulfilling tree on Mount Meru.[69]

See also

References

  1. ^ "Murder of Crows, etc". Word-detective.com. Retrieved 12 November 2011.
  2. ^ Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 119. ISBN 978-1-4081-2501-4.
  3. ^ Winkler, Robert (8 August 2002). "Crow Makes Wire Hook to Get Food". National Geographic. Retrieved 6 February 2011.
  4. ^ "A Murder of Crows". Nature. PBS video. 24 October 2010. Retrieved 6 February 2011. New research indicates that crows are among the brightest animals in the world.
  5. ^ "Crows as Clever as Great Apes, Study Says". National Geographic News. NG Society. 9 December 2004. Retrieved 24 June 2015. Emery and Clayton write, "These studies have found that some corvids are not only superior in intelligence to birds of other avian species (perhaps with the exception of some parrots), but also rival many nonhuman primates."
  6. ^ Barker, F. K.; Cibois, A.; Schikler, P.; Feinstein, J.; Cracraft, J. (2004). "Phylogeny and diversification of the largest avian radiation". Proceedings of the National Academy of Sciences. 101 (30): 11040–5. Bibcode:2004PNAS..10111040B. doi:10.1073/pnas.0401892101. PMC 503738. PMID 15263073.
  7. ^ Linnaeus, C (1758). Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata (in Latin). Holmiae. (Laurentii Salvii). p. 824. Archived from the original on 19 March 2015.
  8. ^ Simpson, D.P. (1979). Cassell's Latin Dictionary (5 ed.). London: Cassell Ltd. p. 883. ISBN 978-0-304-52257-6.
  9. ^ Marzluff, J., Bowman, R. and Donnelly, R. (2001). Avian ecology and conservation in an urbanizing world. Boston: Kluwer Academic Publishers.
  10. ^ Caccamise, D., Reed, L. and Stouffer, P. (1997). Roosting Behavior and Group Territoriality in American Crows. The Auk, 114(4), 628-637.
  11. ^ Bekoff, Mark & Byers, John (1998). Animal Play: Evolutionary, Comparative and Ecological Perspectives.
  12. ^ Chamberlain, Dwight R; Cornwell, George W (1971). "Selected Vocalizations of the Common Crow". The Auk. 88 (3): 613–634. JSTOR 4083753.
  13. ^ Shanbhag, Anirudh P.; Ghosh, Ishita; Umakanth, B. DOI: 10.5829/idosi.gjer.2012.6.1.6184 Interspecific Behavioral Studies of House Crows (Corvus splendens protegatus) and Jungle Crows (Corvus macrorhynchos culminatus) on Mutual Foraging Sites. CiteSeerX 10.1.1.414.3107. doi:10.5829/idosi.gjer.2012.6.1.6184 (inactive 10 July 2019).
  14. ^ Dehaene, Stanislas (2011). The Number Sense: How the Mind Creates Mathematics, Revised and Updated Edition. Oxford University Press. pp. 289–. ISBN 978-0-19-975387-1.
  15. ^ Park, Keeok. Numbers Are Us. Keeok Park. pp. 19–. ISBN 978-0-9843446-3-5.
  16. ^ Rincon, Paul (22 February 2005). "Science/Nature | Crows and jays top bird IQ scale". BBC News. Retrieved 12 November 2011.
  17. ^ Bait-Fishing in Crows
  18. ^ Post to Wall. "Crow tubing upon a slide (video)". Wimp.com. Retrieved 19 December 2013.
  19. ^ Prior, H.; Schwarz, A.; Güntürkün, O. (2008). "Mirror-Induced Behavior in the Magpie (Pica pica): Evidence of Self-Recognition". PLoS Biology. 6 (8): e202. doi:10.1371/journal.pbio.0060202. PMC 2517622. PMID 18715117.
  20. ^ Schmid, Randolph E. (5 October 2007) "Crows Bend Twigs Into Tools". Archived from the original on 31 March 2012. Retrieved 13 March 2009.CS1 maint: BOT: original-url status unknown (link), Associated Press via Discovery Channel
  21. ^ See also the video "Crow bars", from the BBC's The Life of Birds
  22. ^ Katrina Bolton (15 September 2007). "Toads fall victim to crows in NT – ABC News (Australian Broadcasting Corporation)". Abc.net.au. Retrieved 12 November 2011.
  23. ^ "Cane Toad (Bufo marinus)". Ozanimals.com. Retrieved 12 November 2011.
  24. ^ Rogers, Lesley J.; Kaplan, Gisela T. (2004). Comparative vertebrate cognition: are primates superior to non-primates?. New York, New York: Springer. p. 9. ISBN 978-0-306-47727-0.
  25. ^ Nijhuis, Michelle (25 August 2008). "Friend or Foe? Crows Never Forget a Face, It Seems". The New York Times. Retrieved 6 February 2011.
  26. ^ Heinrich, B. (1988). "Winter foraging at carcasses by three sympatric corvids, with emphasis on recruitment by the raven, Corvus corax". Behavioral Ecology and Sociobiology. 23 (3): 141–156. doi:10.1007/BF00300349.
  27. ^ Heinrich, B.; Marzluff, J. M. (1991). "Do common ravens yell because they want to attract others?". Behavioral Ecology and Sociobiology. 28. doi:10.1007/BF00172134.
  28. ^ Crow Facts. crowbusters.com
  29. ^ Allaboutbirds.org, (2014). American Crow. [online] Available at: http://www.allaboutbirds.org/guide/american_crow/lifehistory
  30. ^ Andrea K Townsend and Christopher M Barker (2014). Plastic and the Nest Entanglement of Urban and Agricultural Crows Heiss, R., Clark, A. and McGowan, K. (2009).
  31. ^ Growth and nutritional state of American crow nestlings vary between urban and rural habitats. Ecological Applications, 19(4), 829-839.
  32. ^ McGowan, K.J. "Frequently Asked Questions About Crows", Cornell Lab of Ornithology
  33. ^ Crow Believed to Be Oldest in World Dies. Associated Press via Washington Post (7 July 2006)
  34. ^ "Why West Nile virus kills so many crows", Penn State Center for Infectious Disease Dynamics
  35. ^ "Pacific Region Endangered Species, U.S. Fish and Wildlife Service". Fws.gov. 23 June 2011. Retrieved 12 November 2011.
  36. ^ Lim, H. C., N. S. Sodhi, B. W. Brook, and M. C. K. Soh (2003). "Factors determining the distribution of three invasive bird species in Singapore". Journal of Tropical Ecology. 19 (6): 685–695. doi:10.1017/s0266467403006084. hdl:2440/36842.CS1 maint: Multiple names: authors list (link)
  37. ^ Brook, B. W.; Sodhi, N. S.; Soh, M. C. K.; Lim, H. C. (2003). "Abundance and Projected Control of Invasive House Crows in Singapore". The Journal of Wildlife Management. 67 (4): 808. doi:10.2307/3802688. JSTOR 3802688.
  38. ^ "National Geographic News. 2010. Crow meat comes back—boost sexual potency? Accessed. 17 Oct 2013". News.nationalgeographic.com. 28 October 2010. Retrieved 19 December 2013.
  39. ^ Conover, M. R. (1985). "Protecting vegetables from crows using an animated crow-killing owl model". The Journal of Wildlife Management. 49 (3): 643–645. doi:10.2307/3801687. JSTOR 3801687.
  40. ^ Johnson, R. J. "American crows" (PDF). Internet Center for Wildlife Management. Retrieved 19 December 2013.
  41. ^ Gorenzel, W. P.; Blackwell, B. F.; Simmons, G. D.; Salmon, T. P.; Dolbeer, R. A. (2002). "Evaluation of lasers to disperse American crows, Corvus brachyrhynchos, from urban night roosts". International Journal of Pest Management. 48 (4): 327. doi:10.1080/09670870210151689.
  42. ^ "Crow hunting". nerija.lt. Retrieved 17 March 2013.
  43. ^ Alexander, G.; Mann, T.; Mulhearn, C. J.; Rowley, I. C. R.; Williams, D.; Winn, D. (1967). "Activities of foxes and crows in a flock of lambing ewes". Australian Journal of Experimental Agriculture. 7 (27): 329. doi:10.1071/EA9670329.
  44. ^ Goodwin D. (1983). Crows of the World. Queensland University Press, St Lucia, Qld. ISBN 978-0-7022-1015-0.
  45. ^ Krulwich, Robert (27 July 2009). "The Crow Paradox". Morning Edition. National Public Radio.
  46. ^ Sewall, Katy (25 February 2015). "The girl who gets gifts from birds". BBC.
  47. ^ "Birds that bring gifts and do the gardening". BBC News. 10 March 2015.
  48. ^ Mynors, Roger A. (Translator) (1989). Collected Works of Erasmus: Adages: Ivi1 to Ix100. University of Toronto Press. p. 314.
  49. ^ de Vries, Ad (1976). Dictionary of Symbols and Imagery. Amsterdam: North-Holland Publishing Company. p. 275. ISBN 978-0-7204-8021-4.
  50. ^ a b Thompson, D'Arcy Wentworth (1895). "Jackdaw". A Glossary of Greek Birds. Oxford. p. 89.
  51. ^ Graves, R (1955). "Scylla and Nisus". Greek Myths. London: Penguin. p. 308. ISBN 978-0-14-001026-8.
  52. ^ Kovacs, Maureen Gallery (1989). The epic of Gilgamesh. Stanford University Press. p. 102. ISBN 978-0-8047-1711-3.
  53. ^ This mythology comes from a text in Shanhaijing, among other sources.
  54. ^ Yang, Lihui (2008). Handbook of Chinese Mythology. Oxford University Press. pp. 95–96 and 231. ISBN 978-0-19-533263-6.
  55. ^ The Atlantic Monthly. 34.
  56. ^ Zailer, Xenia (2013). "Dark Shades of Power: the Crow in Hindu and Tantric Religious Traditions". Religions of South Asia. 7 (1–3): 212–229. doi:10.1558/rosa.v7i1-3.212.
  57. ^ Vasudevan, Vidia (26 July 2001). "It's a crow's day". The Hindu. Chennai, India.
  58. ^ Kinsley, David R. (1988). "Tara, Chinnamasta and the Mahavidyas". Hindu Goddesses: Visions of the Divine Feminine in the Hindu Religious Tradition (1 ed.). University of California Press. pp. 161–177. ISBN 978-0-520-06339-6.
  59. ^ Leeming, David Adams (2005). "Crows and ravens". The Oxford companion to world mythology. Oxford University Press. p. 86. ISBN 978-0-19-515669-0.
  60. ^ What Ruling on killing mice and rats. Islamqa.info. Retrieved on 19 April 2014.
  61. ^ "Surat Al-Maidah 5:31". Quran.com. Retrieved 1 May 2015.
  62. ^ Picken, Stuart D.B. (1994). Essentials of Shinto: an analytical guide to principal teachings. Greenwood Publishing Group. p. 96. ISBN 978-0-313-26431-3.
  63. ^ Como, Michael (2009). Weaving and binding: immigrant gods and female immortals in ancient Japan. University of Hawaii Press. pp. 100–103. ISBN 978-0-8248-2957-5.
  64. ^ "Common Ravens - Species Information". Avianweb.com. Retrieved 19 December 2013.
  65. ^ "Medieval Bestiary : Crow".
  66. ^ de Vries, Ad (1976). Dictionary of Symbols and Imagery. Amsterdam: North-Holland Publishing Company. pp. 388–89. ISBN 978-0-7204-8021-4.
  67. ^ "The Crow and the Pitcher". Aesop's Fables.
  68. ^ Dixon-Kennedy, Mike (1998). "Coronis/Corvus". Encyclopedia of Greco-Roman mythology. ABC-CLIO. p. 93. ISBN 978-1-57607-129-8.
  69. ^ Cole, Juan R.I. Baha'u'llah on Hinduism and Zoroastrianism: The Tablet to Mirza Abu'l-Fadl Concerning the Questions of Manakji Limji Hataria.

Further reading

  • Burton, Maurice; Burton, Robert (2002). "Crow". The international wildlife encyclopedia, Volume 10. Marshall Cavendish. ISBN 978-0-7614-7266-7.
  • Franklin Coombs (1978). The Crows: A Study of the Corvids of Europe. Batsford.
  • Gill, B. J. (2003). "Osteometry and Systematics of the Extinct New Zealand Ravens (Aves: Corvidae: Corvus)". Journal of Systematic Palaeontology. 1: 43–58. doi:10.1017/S1477201903001019. Archived from the original on 12 April 2016. Retrieved 14 March 2008.
  • Goodwin, D. (1983). Crows of the World. Queensland University Press. ISBN 978-0-7022-1015-0.
  • Heinrich, Bernd (1991). Ravens in Winter. Vintage Press. ISBN 978-0-679-73236-5.
  • Heinrich, Bernd (1999). Mind of the Raven: Investigations and Adventures with Wolf-Birds. Cliff Street Books. ISBN 978-0-06-093063-9.
  • Kilham, Lawrence (1991). The American Crow and the Common Raven. Texas A&M University Press. ISBN 978-0-89096-466-8.
  • Madge, Steve; Burn, Hillary (1994). Crows and jays: a guide to the crows, jays, and magpies of the world. Houghton Mifflin. ISBN 978-0-395-67171-9.
  • Westerfield, Michael (2011). The Language of Crows: The crows.net Book of the American Crow. Ashford Press. ISBN 978-0-937992-00-5.
  • Worthy, Trevor H.; Holdaway, Richard N. (2002). The Lost World of the Moa: Prehistoric Life of New Zealand. Indiana University Press. ISBN 978-0-253-34034-4.

External links

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 and the hooded crow. Although the American crow and the hooded crow are very similar in size, structure and behavior, their calls are different. The American crow, nevertheless, occupies the same role that the hooded crow does in Eurasia.

From beak to tail, an American crow measures 40–50 cm (16–20 in), almost half of which is tail. Mass varies from about 300 to 600 g (11 to 21 oz). Males tend to be larger than females.

The most usual call is CaaW!-CaaW!-CaaW!.

The American crow is all black, with iridescent feathers. It looks much like other all-black corvids. They can be distinguished from the common raven (C. corax) because American crows are smaller, from the fish crow (C. ossifragus) because American crows do not hunch and fluff their throat feathers when they call and from the carrion crow (C. corone) by the enunciation of their calls.

American crows are common, widespread, and susceptible to the West Nile virus, making them useful as a bioindicator to track the virus's spread. Direct transmission of the virus from American crows to humans is unheard of and unlikely.

Black Order (comics)

The Black Order is a fictional supervillain team appearing in American comic books published by Marvel Comics.

The Black Order appeared in the Marvel Cinematic Universe films Avengers: Infinity War (2018) and Avengers: Endgame (2019). They were also known as the Children of Thanos.

Brown-necked raven

The brown-necked raven (Corvus ruficollis) is a larger bird (52–56 cm in length) than the carrion crow though not as large as the common raven. It has similar proportions to the common raven but the bill is not so large or deep and the wings tend to be a little more pointed in profile. The head and throat are a distinct brownish-black giving the bird its English name, while the rest of the plumage is black glossed with purple, blue or purplish-blue. Like the Common raven, Thick-billed raven and White-necked raven, it is one of the larger raven species. The smaller raven species are the Australian raven, Forest raven, Little raven, Fan-tailed raven and Chihuahuan raven with the Thick-billed raven being the world's largest raven species and the Chihuahuan raven being the smallest. The feathers of this species often fade quite quickly to a brownish black (even the truly black feathers) and the bird can look distinctly brown by the time it moults. The feet, legs and bill are black. The dwarf raven was formerly considered a subspecies (Corvus ruficollis edithae) but this bird now appears to be closer to the pied crow (C. albus) than this species.

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 eastern Asia.

Common raven

The common raven (Corvus corax), also known as the northern raven, is a large all-black passerine bird. Found across the Northern Hemisphere, it is the most widely distributed of all corvids. There are at least eight subspecies with little variation in appearance, although recent research has demonstrated significant genetic differences among populations from various regions. It is one of the two largest corvids, alongside the thick-billed raven, and is possibly the heaviest passerine bird; at maturity, the common raven averages 63 centimetres (25 inches) in length and 1.2 kilograms (2.6 pounds) in mass. Common ravens can live up to 21 years in the wild, a lifespan surpassed among passerines by only a few Australasian species such as the satin bowerbird and probably the lyrebirds. Young birds may travel in flocks but later mate for life, with each mated pair defending a territory.

Common ravens have coexisted with humans for thousands of years and in some areas have been so numerous that people have regarded them as pests. Part of their success as a species is due to their omnivorous diet; they are extremely versatile and opportunistic in finding sources of nutrition, feeding on carrion, insects, cereal grains, berries, fruit, small animals, nesting birds, and food waste.

Some notable feats of problem-solving provide evidence that the common raven is unusually intelligent. Over the centuries, it has been the subject of mythology, folklore, art, and literature. In many cultures, including the indigenous cultures of Scandinavia, ancient Ireland and Wales, Bhutan, the northwest coast of North America, and Siberia and northeast Asia, the common raven has been revered as a spiritual figure or godlike creature.

Corvidae

Corvidae is a cosmopolitan family of oscine passerine birds that contains the crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. In common English, they are known as the crow family, or, more technically, corvids. Over 120 species are described. The genus Corvus, including the jackdaws, crows, rooks, and ravens, makes up over a third of the entire family.

Corvids display remarkable intelligence 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 mirror tests (European magpies) 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 mammals. Their total brain-to-body mass ratio is equal to that of non-human great apes and cetaceans, and only slightly lower than that of humans.They are medium to large in size, with strong feet and bills, rictal bristles, and a single moult each year (most passerines moult twice). Corvids are found worldwide except for the tip of South America and the polar ice caps. The majority of the species are found in tropical South and Central America, southern Asia and Eurasia, with fewer than 10 species each in Africa and Australasia. 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 or have already become extinct.

Corvus (constellation)

Corvus is a small constellation in the Southern Celestial Hemisphere. Its name means "raven" in Latin. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it depicts a raven, a bird associated with stories about the god Apollo, perched on the back of Hydra the water snake. The four brightest stars, Gamma, Delta, Epsilon, and Beta Corvi, form a distinctive quadrilateral in the night sky.

With an apparent magnitude of 2.59, Gamma Corvi—also known as Gienah—is the brightest star in the constellation. It is an aging blue giant around four times as massive as the Sun. The young star Eta Corvi has been found to have two debris disks. Three star systems have exoplanets, and a fourth planetary system is unconfirmed. TV Corvi is a dwarf nova—a white dwarf and brown dwarf in very close orbit.

Corvus Glaive

Corvus Glaive is a fictional supervillain appearing in American comic books published by Marvel Comics. He is a prominent member of the Black Order, a team of aliens who work for Thanos.

Corvus Glaive appeared as one of the Children of Thanos in the Marvel Cinematic Universe films Avengers: Infinity War (2018) and Avengers: Endgame (2019), portrayed by Michael James Shaw.

Crow

A crow is a bird of the genus Corvus, or more broadly a synonym for all of Corvus. The term "crow" is used as part of the common name of many species. Species with the word "crow" in their common name include:

Corvus albus – pied crow (Central African coasts to southern Africa)

Corvus bennetti – little crow (Australia)

Corvus brachyrhynchos – American crow (United States, southern Canada, northern Mexico)

Corvus capensis – Cape crow or Cape rook (Eastern and southern Africa)

Corvus caurinus – northwestern crow (Olympic peninsula to southwest Alaska)

Corvus cornix – hooded crow (Northern and Eastern Europe and Northern Africa)

Corvus corone – carrion crow (Europe and eastern Asia)

Corvus edithae – Somali crow (eastern Africa)

Corvus enca – slender-billed crow (Malaysia, Borneo, Indonesia)

Corvus florensis – Flores crow (Flores Island)

Corvus fuscicapillus – brown-headed crow (New Guinea)

Corvus hawaiiensis (formerly C. tropicus) – Hawaiian crow (Hawaii)

Corvus imparatus – Tamaulipas crow (Gulf of Mexico coast)

Corvus insularis – Bismarck crow (Bismarck Archipelago, Papua New Guinea)

Corvus jamaicensis – Jamaican crow (Jamaica)

Corvus kubaryi – Mariana crow or aga (Guam, Rota)

Corvus leucognaphalus – white-necked crow (Haiti, Dominican Republic, Puerto Rico)

Corvus macrorhynchos – jungle crow (Eastern Asia, Himalayas, Philippines)

Corvus macrorhynchos macrorhynchos – large-billed crow

Corvus macrorhynchos levaillantii – eastern jungle crow (India, Burma)

Corvus macrorhynchos culminatus – Indian jungle crow

Corvus meeki – Bougainville crow or Solomon Islands crow (Northern Solomon Islands)

Corvus moneduloides – New Caledonian crow (New Caledonia, Loyalty Islands)

Corvus nasicus – Cuban crow (Cuba, Isla de la Juventud, Grand Caicos Island)

Corvus orru – Torresian crow or Australian crow (Australia, New Guinea and nearby islands)

Corvus ossifragus – fish crow (Southeastern U.S. coast)

Corvus palmarum – palm crow (Cuba, Haiti, Dominican Republic)

Corvus ruficolis edithae – Somali crow or dwarf raven (Northeast Africa)

Corvus sinaloae – Sinaloan crow (Pacific coast from Sonora to Colima)

Corvus splendens – house crow or Indian house crow (Indian subcontinent, Middle East, east Africa)

Corvus torquatus – collared crow (Eastern China, south into Vietnam)

Corvus tristis – grey crow or Bare-faced crow (New Guinea and neighboring islands)

Corvus typicus – piping crow or Celebes pied crow (Sulawesi, Muna, Butung)

Corvus unicolor – Banggai crow (Banggai Island)

Corvus validus – long-billed crow (Northern Moluccas)

Corvus violaceus – violet crow (Seram) – recent split from slender-billed crow

Corvus woodfordi – white-billed crow or Solomon Islands crow (Southern Solomon Islands)

Grey crow

The grey crow (Corvus tristis), formerly known as the bare-faced crow, is about the same size (42–45 cm in length) as the Eurasian carrion crow (Corvus corone) but has somewhat different proportions and quite atypical feather pigmentation during the juvenile phase for a member of this genus.

The tail feathers are relatively long and graduated and the legs are relatively short. The overall colouring of the adult bird is black with randomly bleached wing and tail feathers. A large region around the eye is quite bare of feathering and shows pinkish-white skin with the eyes a bluish-white. The bill is unusual too in being very variable, bluish on upper mandible and pinkish-white on the lower in some specimens, while on others the whole bill is pinkish white with a darker tip. The forward pointing nasal bristles so often prominent in other Corvus species are very reduced also.

The juvenile bird by comparison has remarkably pale plumage being light brown to cream, the wings, tail and primaries showing blackish-brown and fawn and the head and underparts often almost white.

The species occurs all over the huge island of New Guinea and associated offshore islands in both primary and secondary forest in both lowland and hill forest up to 1350 m.

Feeding is both on the ground and in trees taking a very wide range of items. Fruit seems to be very important making up a large percentage of the intake though small animals such as frogs and aquatic insect larvae are taken from shallow water on sand or shingle beds in rivers. When foraging through the trees the birds keep loose, noisy contact with each other and usually number between 4–8 individuals.

The voice is described as a weak sounding 'ka' or a whining 'caw' with other hoarse sounding notes added when excited.

Hooded crow

The hooded crow (Corvus cornix) (also called hoodie) is a Eurasian bird species in the Corvus genus. Widely distributed, it is also known locally as Scotch crow and Danish crow. In Ireland, it is called caróg liath or grey crow, just as in the Slavic languages and in Danish. In German, it is called "mist crow" ("Nebelkrähe"). Found across Northern, Eastern, and Southeastern Europe, as well as parts of the Middle East, it is an ashy grey bird with black head, throat, wings, tail, and thigh feathers, as well as a black bill, eyes, and feet. Like other corvids, it is an omnivorous and opportunistic forager and feeder.

It is so similar in morphology and habits to the carrion crow (Corvus corone), for many years they were considered by most authorities to be geographical races of one species. Hybridization observed where their ranges overlapped added weight to this view. However, since 2002, the hooded crow has been elevated to full species status after closer observation; the hybridisation was less than expected and hybrids had decreased vigour. Within the hooded crow species, four subspecies are recognized, with one, the Mesopotamian crow, possibly distinct enough to warrant species status itself.

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. It is between the jackdaw and the carrion crow in size (40 cm (16 in) in length) but is slimmer than either. The forehead, crown, throat and upper breast are a richly glossed black, whilst the neck and breast are a lighter grey-brown in colour. The wings, tail and legs are black. There are regional variations in the thickness of the bill and the depth of colour in areas of the plumage.

Little crow (bird)

The little crow (Corvus bennetti) is an Australian species of crow, very similar to the Torresian crow in having white bases to the neck and head feathers (shown when ruffled in strong wind) but slightly smaller (38–45 cm in length) and with a slightly smaller bill. It has the same white iris that distinguish the Australian species from all other Corvus except a few island species to the north of Australia, and one from Eurasia, the jackdaw (Corvus monedula). Like the Australian raven, this species has a blue ring around the pupil.

Palm crow

The palm crow (Corvus palmarum) is a relatively small black bird in the crow family that occurs mostly on the large Caribbean island of Hispaniola, itself divided into the two countries of Haiti and the Dominican Republic. It was formerly quite frequent on Cuba but has become severely reduced in number and may be almost extinct there. This form is slightly smaller and is usually separated as a sub-species called Corvus palmarum minutus. Both forms are usually now given the respective common names of Hispaniolan palm crow and Cuban palm crow to distinguish them.

Both forms appear to be closely related to the fish crow (C. ossifragus) of the East Coast of the United States and also two smaller species, the Tamaulipas crow (C. imparatus) and Sinaloan crow (C. sinaloae) of Mexico and forms a species group with them.

The Dominican local name for the palm crow is cao, which is onomatopoeic of the simple and repetitive call of this bird. There it is locally common, mainly in mountain pine forests and also around the area of Lake Enriquillo.

Pied crow

The Pied Crow (Corvus albus) is a widely distributed African bird species in the crow genus.

Structurally, the Pied Crow is better thought of as a small crow-sized Raven, especially as it can hybridise with the Somali Crow (Dwarf Raven) where their ranges meet in the Horn of Africa. Its behaviour, though, is more typical of the Eurasian Carrion Crows, and it may be a modern link (along with the Somali Crow) between the Eurasian crows and the Common Raven.

Raven

A raven is one of several larger-bodied 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", and these appellations have been assigned to different species chiefly on the basis of their size, crows generally being smaller than ravens.

The largest raven species are the common raven and the thick-billed raven.

Ravn Alaska

Corvus Airlines d.b.a. Ravn Alaska is a regional airline that specializes in serving the small communities in the US state of Alaska. The airline is headquartered in Anchorage, which is also home to the primary hub for Ravn, Ted Stevens Anchorage International Airport.

Corvus Airlines operates all of its flights using the Ravn Alaska brand. The company pronounces its name Ravn like the bird, Raven.

Hageland Aviation Services and Frontier Flying Service, the sister airlines of Corvus, also fly under the Ravn brand as Ravn Connect. Hageland Aviation Services operates scheduled passenger flights for Ravn Alaska, while Frontier Flying Service operates cargo and charter services.

Ravn has a partnership with Alaska Airlines, allowing passengers to book codesharing flights and allowing passengers on most Ravn flights to earn miles in Alaska's Mileage Plan frequent-flyer program.

Rook (bird)

The rook (Corvus frugilegus) is a member of the crow family in the passerine order of birds. It is found in Eurasia, its range extending from Scandinavia and western Europe to eastern Siberia. It is a large, gregarious, black bird, distinguished from similar species by the whitish featherless area on the face. Rooks nest collectively in the tops of tall trees, often close to farms or villages, the groups of nests being known as rookeries.

Rooks are mainly resident birds, but the northernmost populations may move southwards to avoid the harshest winter conditions. The birds form flocks in winter, often in the company of other Corvus species or jackdaws. They return to their rookeries and breeding takes place in spring. They forage on arable land and pasture, probing the ground with their strong bills and feeding largely on grubs and soil-based invertebrates, but also consuming cereals and other plant material. Historically, farmers have accused the birds of damaging their crops, and have made efforts to drive them away or kill them. Like other corvids, they are intelligent birds with complex behavioural traits and an ability to solve simple problems.

Slender-billed crow

The slender-billed crow (Corvus enca) is a Passerine bird of the family Corvidae, in the genus Corvus. The violet crow has been found to be distinct genetically and separated as Corvus violaceus.It is found in Brunei, Indonesia, Malaysia, and the Philippines. Its natural habitats are subtropical or tropical moist lowland forest and subtropical or tropical mangrove forest.

Extant species of family Corvidae
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