Common Raven - Corvus corax

Common Raven

Corvus corax

Order : Passeriformes

Family : Corvidae ;

Biometrics :

Size : 56 à 69 cm
Wingspan : 116 à 118 cm
Weight : 690 à 1600 gr

Longevity : 16 years

IUCN conservation status :

Extinct

Threatened

Least
concern

Extinc
in the Wild

Near
threatened

Not
evaluated

EX EW CR EN VU NT LC NE

Geographic range :

Synonyms : Voron (ru), Korp (sv), Cuervo (es), Corvo imperiale (it), Kolkrabe (al), Raaf (nl), Common Raven (en)

Physical description :
Common Raven has glossy black plumage, with blue-purple iridescent feathers. It shows elongated shaggy feathers on throat; they are rounded, as a semicircular fan. They are used in social communication. It has long pointed wings. Primaries are obviously separated when it soars. Tail is wedge-shaped and often slightly fanned. It is a large Raven.
It has robust long black beak, slightly curved. Its bill is heavier than crow's beaks, and it is covered with hard hair on the base of upper mandible.
Eyes are dark brown, almost black. Feet and short legs are black.
Sexes are similar in plumage, but male is slightly larger than female.
Juvenile is similar to adult, but it lacks glossy feathers. Flight feathers are mostly brown with wear.

Voice :
Sound from CD 'Tous les Oiseaux d'Europe' by Jean C. Roché by courtesy of Sittelle and CEBA. Common Raven is very vocal. According to different purposes and social contexts, it utters varied series of calls and non-vocal sounds. It may utter from 15 to 30 kinds of vocalizations.
Usual calls are alarm calls, chase calls, and others to defend territory. They are high-pitched and raucous 'praaak-praaak' in flight.
They are able to mimic other animals' sounds, but they only can utter a wide diversity of calls, and create sounds resembling other species' calls.
Common call is a deep 'croak' or a hoarse 'rrronk', and a knocking 'tok-tok-tok'.
Non-vocal sounds are wing whistles and bill snapping. (Boarman and Heinrich, 1999).

Habitat : Common Raven lives in various 'wild' habitats, from coastal cliffs to high mountains. We also find them in open woodlands and forests, even in low areas. They nest in cliffs areas, but they are found in tundra and boreal forest, and also in urban areas.
GEOGRAPHIC RANGE: Common Raven is resident in its range. It lives in North America except in south eastern part, Asia, Northern Africa and Europe. It is one of the most widespread in the world.

Behaviour : Common Raven is attracted to carrion, and insects found on this carrion. It also eats afterbirth of ewes and large mammals. It takes its food from the ground. It may store all kinds of food.
They are rarely seen hunting, even eggs or chicks at nest. They forage in large flocks in areas where food resources are abundant.
Common Raven defends strongly its young, chasing predators away while calling. But adults are wary when they approach new carrion, and they prefer to wait that no danger is around.
They form loose flocks during the day, and gather for roosting at night. They are seen in pairs or small groups.
Common Raven communicates by vocalizations, but also by physical displays. Pair defending territory and nest site chases intruders for long distance, and may engage aerial fight.
Common Raven is able to learn solutions to newly encountered problem. They don't migrate, but some seasonal movements are observed to avoid extreme weather. This smart species can survive in Arctic, as well as in desert or temperate environments.
Courtship display is not known very well. Displays seen occur all year round, most intense in fall and winter, and include acrobatic flights. Pairs stay together all the year and certainly for life. They are monogamous.
Courtship displays on the ground include bowing with elongated neck and fluffing throat feathers. Male has fanned wings and tail, stretching its neck upwards while is bowing with bill downwards. Sometimes it hops in the air, and performs preening on female's head.
Female invites to copulation crouching slightly and moving its wings (opening, extending or dropping) and shaking or quivering its raised tail.

Flight : Common Raven has an agile and powerful flight. It also glides and soars on thermals in great heights. They may perform aerial fights and displays. Common Raven is an acrobatic flier, making rolls and elaborate movements in flight. It may fly upside down for one kilometre.

Reproduction-nesting : Common Raven nests in cliffs or in large trees, from 3 to 20 metres above the ground. Nest is a bulky basket made with sticks, reeds and decayed vegetable matter. Inner cup is made with twigs, and lined with soft materials, sheep's wool, lichen, fur, grasses, mud and paper. Same nest is often re-used with new material added each spring.
Female lays 3 to 7 pale bluish-green or olive-green eggs, blotched with dark olive-brown. Incubation lasts about 18 to 21 days, by female. She is fed by the male while she incubates. Chicks hatch altricial, with sparse down. They are fed by both parents, by regurgitated food and water stored in a throat pouch.
Young leave the nest between 5 and 7 weeks after hatching. They may leave the area and their family, or remain with their parents for a more extended period. They reach their sexual maturity at about three years.
This species produces only one brood per season.

Food habits : Common Raven feeds mainly on carrion. But it consumes arthropods, amphibians, small mammals, birds and reptiles. They also feed on vegetable food, such as grains, acorns, fruits and buds.

Protection / threats : Common Raven has some predators such as hawks, eagles, other ravens, owls and martens. Other large raptors and coyote attack nest and fledglings.
Common Ravens have been persecuted by humans for preying on lambs and crops. They may be shot, poisoned or captured in traps, in order to protect other species. Now, they are protected and populations in North America are increasing all across their range. This species is listed as Endangered by Kentucky and Tennessee.
Raven has often played important roles in cultures, mythologies and writings.

Other links :
Iucn
Birdlife

Specification sheet created by Nicole Bouglouan

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