Crow

? Crow
200px American Crow
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Order: Passeriformes Family: Corvidae Genus: Corvus Linnaeus, 1758
Species
See text

The true crows are in the genus Corvus. They are large passerine birds. All temperate continents (except South America) and several offshore and oceanic islands (including Hawaii) have representatives of the 40 or so members of this genus.

Crows in the genus Corvus appear to have evolved in central Asia and radiated out into North America, Africa, Europe, and Australia.

The latest evidence appears to point towards an Australasian origin for the early family (Corvidae) though the branch that would produce the modern groups such as jays, magpies and large predominantly black Corvus Crows had left Australasia and were now developing in Asia. Corvus has since re-entered Australia (relatively recently) and produced five species with one recognised sub-species.

They range in size from the relatively small pigeon-sized jackdaws (Eurasian and Daurian) to the Common Raven of the Palearctic region and Thick-billed Raven of the highlands of Ethiopia.

In literary and fanciful usage, the collective noun for a group of crows is a murder. However, in practice most people, and especially scientists, use the more generic term flock.

Color and society

Extra-specific uses of colour in crow societies

Many crow species are all black. Most of their natural enemies, the raptors or "falconiformes", soar high above the trees, and hunt primarily on bright, sunny days when contrast between light and shadow is greatest. Crows take advantage of this by maneuvering themselves through the dappled shades of the trees, where their black color renders them effectively invisible to their enemies above, in order to set up complex ambush attacks. Thus, their black coloring is of great strategic importance to their societies. It is perhaps here where we find the greatest difference between ravens and crows; ravens tend to soar high in the air as raptors do, and like raptors, are usually the target of ambushes by crows. Crows do not appear to perceive ravens as their own kind, but instead treat them as raptors. ^{[citation needed]}

While hawks tend to be the primary daytime predators of crows, their most deadly predators, in many areas, are the owls that hunt by night, preying upon crows sleeping helplessly in their roosts. Presumably their dark color is particularly helpful in blending into nighttime shadows. Crows also will often mob owls much more fiercely when they find them in daylight than they do hawks and other raptors. Frequently crows appear to "play" with hawks, taking turns "counting coup" while escorting the raptor out of their territory. Their attacks on owls, on the other hand, possess a definite serious quality.

Intra-specific uses of color in crow societies

Even in species characterized by being all black, one will still occasionally find variations, most of which appear to result from varying degrees of albinism, such as:

• an otherwise all-black crow stunningly contrasted by a full set of brilliant, pure-white primary feathers.
• complete covering in varying shades of grey (generally tending toward the darker side)
• blue or red, rather than swarthy eyes (blue being more common than red).
• Some combination of the above

The treatment of these rare individuals may vary from group to group, even within the same species. For example, one such individual may receive special treatment, attention, or care from the others in its group, while another group of the same species might exile such individuals, forcing them to fend for themselves. The reason for such behaviors, and why these behaviors vary as they do, has yet to be studied.

Intelligence

As a group, the crows show remarkable examples of intelligence. They top the avian IQ scale[1]. Crows and ravens often score very highly on intelligence tests. Crows in the northwestern U.S. (a blend of Corvus brachyrhynchos and Corvus caurinus) show modest linguistic capabilities and the ability to relay information over great distances, live in complex, hierarchic societies involving hundreds of individuals with various "occupations", and have an intense rivalry with the area's less socially advanced ravens. One species, the New Caledonian Crow, has recently been intensively studied because of its ability to manufacture and use its own tools in the day-to-day search for food. Wild hooded crows in Israel have learned to use bread crumbs for bait-fishing. Crows will engage in a kind of air-jousting, or air-chicken to establish pecking order.

Calls

Crows make a wide variety of calls or vocalizations. Whether the crows' system of communication constitutes a language is a topic of debate and study. Crows have also been observed to respond to calls of other species; this behaviour is presumably learned because it varies regionally. Crows' vocalizations are complex and poorly understood. Some of the many vocalizations that crows make are a "caw", usually echoed back and forth between birds, a series of "caws" in discrete units, counting out numbers, 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 regionally. The pattern and number of the numerical vocalizations have been observed to change in response to events in the surroundings (i.e. arrival or departure of crows). Crows can hear sound frequencies lower than those that humans can hear, which complicates the study of their vocalizations.

Species

Crow on a branch, Maruyama Kyo (1733-1795)

Australian species

• Australian Raven C. coronoides
• Forest Raven C. tasmanicus
  • Relict Raven C. t. boreus
• Little Crow C. bennetti
• Little Raven C. mellori
• Torresian Crow C. orru

New Zealand species

• Chatham Islands Raven, Corvus moriorum †
• New Zealand Raven, Corvus antipodum †
  • North Island Raven, Corvus antipodum antipodum †
  • South Island Raven, Corvus antipodum pycrafti †

North American species

• American Crow C. brachyrhynchos
• Chihuahuan Raven C. cryptoleucus
• Common Raven C. corax
• Fish Crow C. ossifragus
• Northwestern Crow C. caurinus
• Tamaulipas Crow C. imparatus
• Sinaloan Crow C. sinaloae

African species

• Cape Crow C. capensis
• Fan-tailed Raven C. rhipidurus
• Pied Crow C. albus
• Somali Crow or Dwarf Raven C. edithae
• Thick-billed Raven C. crassirostris
• White-necked Raven C. albicollis

North African and Asia Minor species

• Brown-necked Raven C. ruficollis
• Hooded Crow C. cornix
• Common Raven C. corax
• Fan-tailed Raven C. rhipidurus

European species

• Carrion Crow C. corone
• Common Raven C. corax
• Hooded Crow C. cornix
• Jackdaw C. monedula
• Rook C. frugilegus

Asian species

• Carrion Crow C. corone
• Collared Crow C. torquatus
• Daurian Jackdaw C. dauricus
• House Crow C. splendens
• Jungle Crow C. macrorhynchos
• Rook C. frugilegus
• Common Raven C. corax

The islands between Southeast Asia and Australia have several species, as do the West Indies off the south east coast of the North American continent. A few Pacific islands (including Hawaii) have representative species also.

Various island species

• Hawaiian Crow or 'Alala C. hawaiiensis (formerly C. tropicus)
• New Caledonian crow C. moneduloides
• Cuban Crow C. nasicus
• Jamaican Crow C. jamaicensis
• Palm Crow C. palmarum
• White-necked Crow C. leucognaphalus
• White-billed Crow C. woodfordi
• Grey Crow C. tristis

For more information regarding crows, see the individual species.

For more information regarding relatives of the crows, such as magpies and jays, see Corvidae.

Mythology and folklore

Crows, and especially ravens, often feature in legends or mythology as portents or harbingers of doom or death, because of their dark plumage, unnerving calls, and tendency to eat carrion. They are commonly thought to circle above scenes of death such as battles.

In Native American folklore, Crow is often seen as a similar trickster to Coyote. However, Crow's tricks tend to be more out of malice and they rarely (if ever) are portrayed as a hero. One possible explanation for this is that crows are often considered a pest to crops, which the tribes who came up with the stories featuring Crow needed to survive.

In the Epic of Gilgamesh, the Chaldean myth, the character Utnapishtim releases a dove and a raven to find land, similar to what Noah does in the book of Genesis. However, in the Epic of Gilgamesh, the dove merely circles and returns. Only then does Utnapishtim send forth the raven, who does not return. Utnapishtim extrapolates from this that the raven has found land, which is why it hasn't returned. This would seem to indicate some acknowledgement of crow intelligence, which may have been apparent even in ancient times, and to some might imply that the higher intelligence of crows, when compared to other birds, is striking enough that it was known even then.

In occult circles, distinctions are sometimes made between crows and ravens. In mythology and folklore as a whole, crows tend to be symbolic more of the spiritual aspect of death, or the transition of the spirit into the afterlife, whereas ravens tend more often to be associated with the negative (physical) aspect of death. However, few if any individual mythologies or folklores make such a distinction, and there are ample exceptions. Another reason for this distinction is that while crows are typically highly social animals, ravens don't seem to congregate in large numbers anywhere but a) near carrion where they meet seemingly by chance, or b) at cemeteries, where large numbers sometimes live together, even though carrion there is no more available (and probably less attainable) than any road or field. ^{[citation needed]}

Amongst Neopagans, crows are often thought to be highly psychic and are associated with the element of ether or spirit, rather than the element of air as with most other birds. This may in part be due to the long-standing occult tradition of associating the color black with "the abyss" of infinite knowledge (see akasha), or perhaps also to the more modern occult belief that wearing the "color" black aids in psychic ability, as it absorbs more electromagnetic energy, since surfaces appear black by absorbing all frequencies in the visible spectrum, reflecting no color.

In contrast with their association with death, in the 2004 computer game Half-Life 2, ravens represent hope amidst destruction, because the Combine Empire's takeover - and fascistic rule - of the Earth has caused so much destruction it's a wonder any of the Earth's native wildlife survived at all.

Gods and goddesses associated or identified with crows and ravens

A very incomplete list includes the eponymous Pacific Northwest Native figures Raven and Crow, the ravens Hugin and Munin, who accompany the Norse god Odin, the Celtic goddesses the Mórrígan and/or the Badb (sometimes considered separate from Mórrígan), and Shani, a Hindu god who travels astride a crow.

See also

• List of Corvus species
• Scarecrows
• Ischys for the Greek myth of why the crow's feathers are black.
• To eat boiled crow

External links

• Frequently Asked Questions About Crows
• crows.net: The Language & Culture of Crows
• In the Company of Crows and Ravens, by John M. Marzluff and Tony Angell
• Crow photographs and comments
• Video of crow making and using tools
• More info on tool use by crows, with references

References

ISBN links support NWE through referral fees

• Gill, B. J. 2003. Osteometry and systematics of the extinct New Zealand ravens (Aves: Corvidae: Corvus). Journal of Systematic Palaeontology 1: 43-58.
• Worthy, T.H., Holdaway R.N., 2002, The lost world of the Moa: Prehistoric Life of New Zealand, Indiana University Press, Bloomington. ISBN 0253340349.

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