Search This Blog

Saturday, January 17, 2015

Species Fact Profile: Northern Raven (Corvus corax)

Northern Raven
Corvus corvax (Swainson, 1827)

Range: Europe (includes British Isles and Iceland), Asia, North Africa, Asia (excluding South and South East Asia), North America, Australia
Habitat: Tundra, Grassland, Desert, Woodlands, Cliffs
Diet: Carrion, Small Vertebrates, Eggs, Insects, Grains, Nuts, Fruits
Social Grouping: Solitary, Paired, Small Flocks
Reproduction: Monogamous, breed in February of March, 4-6 eggs laid in a solid nest, incubated for 20 days by female, chicks fledge at 6 weeks, are sexually mature at 3 years
Lifespan: 20 Years (Wild), 80 Years (Captivity)
Conservation Status: IUCN Least Concern

  • Largest perching bird in the world, body length 54-67 centimeters, wingspan 115-130 centimeters, weight 690-1625 grams, females are slightly smaller than males
  • Glossy black plumage often has green or lilac sheen, the throat feathers are shaggy, bill is very thick and heavy-looking; juveniles are darker, browner than adults
  • Fairly sedentary, does not travel widely or migrate, chicks tend not to disperse further than 30 kilometers from hatching locations; populations at the edges of the range may make small, seasonal movements to avoid extreme weather.
  • Very vocal, with over 30 calls having been identified; they can mimic other animals (including human speech); non-vocal communication involves wing whistles and bill snaps
  • Very acrobatic fliers, have been seen flying upside for extended distances, doing somersaults
  • Among the most intelligent of birds, seem capable of learning innovative solutions, skill problem solvers; the appear to like playing games (sometimes with other species, such as otters), and will sometimes use objects as tools
  • Will form partnerships with other species, and have been observed following humans or cowbirds for nests to raid
  • Adults have few predators, but tend to be very wary, often will not approach suspicious looking carrion until other scavenging birds have tasted it first; parents will vigorously defend nest from predators.
  • Very prominent role in the mythology and folklore of Europe, the Middle East, and Native Americans (often depicted as a trickster figure) - prominent roles include Noah's Ark, King Arthur, messengers of the Norse God Odin, and guardians of the Tower of London, but are best known from Edgar Allen Poe's poem, The Raven
  • National bird of Bhutan, where the king wears the Raven Crown
  • Persecuted for years by farmers and gamekeepers (as they will occasionally prey on small livestock); they have been extirpated in some areas, but have been re-established in others, and are becoming more common in rural areas
  • Predation by ravens (especially of nests) has complicated conservation efforts of some endangered species, such as desert tortoises, Steller's eiders, and California condors, leading to culling in some conservation areas
  • A variable number of subspecies (8-11) are recognized acorss the species range, with the nominate form being in Europe

No comments:

Post a Comment