Common Raven

Identifying Features
Corvus corax is 22-30 inches in length, has a 40-59 inch wing span, and weighs 1.5-4.4 lbs. C. corax is one of the heaviest passerines. You can tell them apart from crows by their large curved bill and longish graduated wedge shaped tail. They have a deep, distinctive call with a wide complex vocabulary. While in flight, the raven’s feathers make a creaking sound similar to rustled silk.  Due to a rare genetic mutation some crows in the Qualicum area of Vancouver Island appear white with blue eyes.  According to Mike Yip this isn’t albinism since they have pigment.  It is termed leucistic and refers to the reduction in all types of pigment, not just the lack of melanin as in albinism.

Habitat
C. corax thrives in varied, diverse climates all over the world. These range through artic and temperate habitats in North America and Eurasia to the deserts of North Africa, and islands in the Pacific Ocean. This bird is common in Scotland, Wales, northern England, and west Ireland. In Tibet, they have been recorded at altitudes up to 5000m (16,400ft) and 6,350 (20,600ft) on Mount Everest. They are restricted to Sindh district of Pakistan and adjoining regions of north-west India. Most prefer wooded and costal areas.

Food
Ravens are omnivorous. Their diet normally containing insects, berries, seeds, eggs/young of other birds, small mammals, carrion (the flesh of animals killed by other predators),  and they will often eat things not considered “food” (such as human trash, in an urban environment). It’s been said ravens will hunt alongside packs of wolves, sharing their kill. It’s also been said they will go for the eyes first, typically seen in Nordic images. There is evidence supporting these tales, since eye tissue is softer and easier for birds to pick at, and wolves do some of the shredding of the meat, making it a lot easier for ravens to eat. They are often seen as a dark symbol in western culture for their taste for flesh, but are an important part of the ecosystem, as seen in aboriginal tales. They sometimes even eat noxious weeds.

Predators
They are mostly hunted by birds of prey or other scavengers. Hawks, owls, other ravens, and martens are common predators, though most animals don’t seem to go after ravens as a major food source.

Life Cycle
C. corax mate for life. They start showing courtship behavior at 3-4 years of age, around mid-January. Courting rituals include males soaring, swooping, and tumbling in front of females. They will also fly together and preen each other. By mid-March the couple starts roosting and the female typically lays 3-7 green blotched eggs. The female incubates and is fed by her mate during the 3-4 week incubation period. After hatching, both parents feed the young by regurgitating food and water (stored in a throat patch). The young tend to leave the nest after 5 weeks.  In the wild they generally live between 10 to 15 years but have been known to live up to more than 40 years in captivity.

Photos courtesy of Mike Yip

References
Arizona-Sonora Desert Museum (2012), Common Raven, Arizona-Sonora Desert Museum. Retrieved June 11^th, 2012.
www.desertmuseum.org/books/nhsd_raven.php

The Alaska Zoo, Common Raven Fast Facts, The Alaska Zoo. Retrieved June 11^th, 2012.
www.alaskazoo.org/common-raven

Cornell University (2012), Common Raven, The Cornell Lab or Ornithology. Retrieved June 11^th, 2012.
www.birds.cornell.edu/birdsleuth/modules/exploring-bird-behavior/bird-guide/common-raven