Vancouver Avian Research Centre

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Species: Common Raven Corvus corax

Description:

The Common Raven is a majestic bird that prefers wild open areas but makes occasional forays into urban settings. More often heard than seen, the image this bird conjures to one’s mind is wilderness: open woodland in winter and the distinctive croak call of the raven in the distance.

It is known for its high intelligence and numerous anecdotes of its cleverness at procuring food such as stealing an ice-fisherman’s catch.

This species has a cosmopolitan holarctic distribution. In North America its distribution ranges from the Arctic tundra south to Nicaragua.

Identification:

General: It is the largest passerine in North America with a length up to 69 centimeters and a mass ranging from 689 to 1625 grams. Plumage is all-black, throat-hackles prevalent, a robust bill and that distinctive call “quork”. They have a tendency to soar during flight and revealing the wedge-shaped tail.

Adult Male: Similar to the female but may be larger.

Adult Female: Similar to male but may be smaller.

Juvenile: Possess similar plumage to adults but is duller. Eyes have a blue-gray iris compared to the dark brown iris of adults.

Similar Species: The Northwestern Crow and other crow species are smaller and more gregarious. The wedge-shaped tail identifies the raven from its smaller crow cousins during flight. The Chihuahuan Raven is smaller but slightly larger than the American Crow and its distribution is from southwestern US to northern Mexico.

Behavior: They often travel in pairs and make frequent contact calls to each other. Younger birds may flock and where food is concentrated ravens may form larger groups. Their resourcefulness and observed play behavior have endeared them to some observers.

Habitat: Ravens prefer less spoiled habitats compared to crows. They can be found in forests, rocky cliffs, scrubland and most other habitats in their range except for tropical rainforests.

Information:

The Common Raven is divided into 8 recognized subspecies across its range. Corvus corax principalis is the subspecies encountered in northern North America and Greenland. C c sinuatus is another North American subspecies that occurs in south central US and Central America. It is distinguished from its northern cousin by its smaller size.

They are generally year round residents throughout their range but populations that face extreme conditions like the Arctic winter may make seasonal movements.

Ravens tend to form life long pairs where courting starts at a young age but may not bond for another 2 or 3 years. Infidelity has been documented from this normally monogamous species. Most clutches are started between March or April where 3 to 7 eggs are laid and are incubated by the female. Nestlings fledge between 5 to 7 weeks of age but may stay with their parents for another six months. They are long-lived birds and have been recorded to live more than 13 years in the wild. In captivity, they can live as long as 80 years.

Ravens and their nests are seldom preyed upon. Ravens will be highly territorial and will aggressively defend against predators. Potential nest predators include marten, large owls and other raptors, coyotes and other ravens. Their intelligence predisposes them to be cautious when approaching novel carrion. They will wait until other scavengers such as crows and jays have tested the carcass. Sometimes another carnivore like the Gray Wolf would be called to help dispose of a carcass.

Raven has been a prominent figure in the mythology of many indigenous North American cultures especially among the Pacific coast. In Coast Salish creation cycles the islands off BC’s coast were formed from the mud that fell off of Raven’s bill and feet. In Haida, Raven encouraged the First Peoples to leave a clam shell. In Tlingit, Raven’s cunning outsmarted a Chief who selfishly imprisoned the sun for himself.

Conservation Status: (Least Concern)

Ravens have been branded crop raiders and livestock predators by some and have been persecuted. There have been regional extirpations due to habitat loss and hunting but ravens are in no danger of extinction. In other parts of their range they have increased thanks to human influence ie 16 X from their original population over 25 years in the Mojave Desert. There is a concern that the Common Raven could endanger the recovery of certain species at risk such as the Marbled Murrelet and Steller’s Eider.
 

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