North American Common Raven Habitats: Black Body, Cup Nest, Green Egg

Summary: North American common raven habitats year-round from Alaska and Canada southwestward into Central America get black bodies from green eggs in cup nests.

In sunlight, iridescence accounts for a blue or purple sheen in the black plumage of the North American common raven (Corvus corax); Cypress Provincial Park, Metro Vancouver Regional District (MVRD), southwestern British Columbia, western Canada; October 2007: Clayoquot, CC BY SA 3.0 Unported, via Wikimedia Commons

North American common raven habitats afford cultivators clean lifestyles through Corvidae family predatory wildlife associations with carrion and garbage and naturalists distribution ranges from Canada to the coastal United States and Mexico.

Common ravens bear their common name for widespread abundance and from sounds audible one mile (1.61 kilometers) away and the scientific name Corvus corax (raven raven). Ornithologists consider seven to 10 Africa-, America-, Asia-, Europe-based subspecies subsequent to Carl Linnaeus's (May 23, 1707-Jan. 10, 1787) nominate Corvus corax corax classification in 1758. Bill shapes, body sizes, color subtleties and distribution ranges drive subdivisions into canariensis, clarionensis, hispanus, kamtschaticus, laurencei (or subcorax), principalis, sinuatus, tibetanus, tingitanus and varius subspecies.

Fifteen-year lifespans expect every habitat in all of Alaska and Canada, most of Mexico and the United States in the Appalachians and west of the Rockies.

February through April facilitate brooding one three- to seven-egg clutch in crevices or tree forks or on ledges at 45- to 80-foot (13.72- to 24.38-meter) heights.

Monogamous parents-to-be gather branches, earth, gorse, grapevines, grass, heather, moss, sticks and twigs into bark-, fur-, grass-, leaf-, moss-, wool-lined cups atop the previous year's nests. Six-inch- (15.24-centimeter-) deep, 2- to 4-foot (0.61- to 1.22-meter) inner, 1-foot (0.31-centimeter) outer diameter nests house non- or semi-glossy, rough or smooth, subelliptical to oval eggs. Mothers-to-be initiate 18- to 25-day incubations before the last black-, gray-, olive-, olive- or purple-brown-blotched, mottled, speckled, spotted, streaked, blue-green, brown-green or olive-green egg is laid.

Predatory American martens, bald eagles, coyotes, golden eagles, great horned owls, human hunters, northern goshawks, peregrine falcons and red-tailed hawks jeopardize North American common raven habitats.

Hatchlings of 1.58- to 2.68-inch (40- to 68-millimeter) by 1.14- to 1.58-inch (29- to 40-millimeter) eggs know brown, short, thick down on backs, heads and thighs.

Purple-pink mouths and yellow-flesh gape flanges let clumsy, helpless hatchlings live off food from both parents before leaving cup nests five to six weeks after hatching. Nestlings, always hatched from eggs laid one day apart, maintain contact with parents from roosts no more than 20 miles (32.19 kilometers) away from birth nests. Adults need acorns, almonds, barley, berries, buds, carrion-fed beetles, corn, crustaceans, fish, frogs, fruits, grasshoppers, lizards, maggots, mice, scorpions, seeds, spiders, tortoises, walnuts, wheat and worms.

North American common raven habitats up to 16,404.2-foot (5,000-meter) altitudes above sea level offer winter's coldest temperatures at minus 60 degrees Fahrenheit (minus 51.11 degrees Celsius).

Almonds, apples, blueberries, cherries, cranberries, dogwood, figs, grapes, hemlock, oak, peanuts, poison-ivy, poison-oak, pokeberries, pumpkins, sumac, sunflowers, walnuts and white pine promote common raven life cycles.

Brown and dull black, non-glossy plumage, diminutive sizes and eyes browning from initial blue-gray versus smaller sizes respectively qualify as juvenile and as mature female hallmarks. Adult males reveal black curved bills, flared outer wing feathers, glossy purple-black upper-parts, gray necks, large heads, long feet, shaggy throats, strong legs and wedge-shaped tails. Acrobatic, direct, steady soaring on 3.81- to 3.87-foot (1.16- to 1.18-meter) wingspans suggest 22.05- to 27.16-inch (56- to 69-centimeter), 24.3- to 57.32-ounce (689- to 1,625-gram) adults.

North American common raven habitats teem with 33 sounds, from carrying, deep, grating, gurgling, harsh, rasping, shrill clucks, croaks and knocks to krruuk and tok vocalizations.

illustration of egg of common raven; Henry Seebohm, Coloured Figures of the Eggs of British Birds (1896), Plate 55 (between pages 224-225): Public Domain, via Biodiversity Heritage Library

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

In sunlight, iridescence accounts for a blue or purple sheen in the black plumage of the North American common raven (Corvus corax); Cypress Provincial Park, Metro Vancouver Regional District (MVRD), southwestern British Columbia, western Canada; October 2007: Clayoquot, CC BY SA 3.0 Unported, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Raven_Cypress_Provincial_Park_2.JPG

illustration of egg of common raven; Henry Seebohm, Coloured Figures of the Eggs of British Birds (1896), Plate 55 (between pages 224-225): Public Domain, via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/7272603

For further information:

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Available via MDZ (Münchener DigitalisierungsZentrum Digitale Bibliothek) Digitale Sammlungen @ http://reader.digitale-sammlungen.de/en/fs1/object/display/bsb10306825_00018.html

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Available via Biodiversity Heritage Library @ http://biodiversitylibrary.org/page/3268074

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