Great Horned Owl

Bubo virginianus

Summary 3

The Great Horned Owl, (Bubo virginianus), also known as the Tiger Owl, is a large owl native to the Americas. It is an adaptable bird with a vast range and is the most widely distributed true owl in the Americas.
Like most owls, the Great Horned Owl makes great use of secrecy and stealth. Due to its natural-colored plumage, it is well camouflaged both while active at night and while roosting during the day. Despite this, it can still sometimes be spotted on its daytime roosts, which are usually in large trees but may occasionally be on rocks. This regularly leads to their being mobbed by other birds, especially American Crows (Corvus brachyrhynchos). Since owls are, next to Red-tailed Hawks, perhaps the main predator of crows and their young, crows sometimes congregate from considerable distances to mob owls and caw angrily at them for hours on end. When the owls try to fly off to avoid this harassment, they are often followed by the corvids.

Owls have spectacular binocular vision, allowing them to pinpoint prey and see in low light. The eyes of a Great Horned Owl are nearly as large as those of a human being and are immobile within their circular bone sockets. As a result, instead of turning its eyes, an owl must turn its whole head, the neck capable of rotating a full 270 degrees, in order to see in various directions without moving its entire body.[3]

An owl's hearing is as good as, if not better than, its vision. Owls have better depth perception[citation needed] and better perception of sound elevation (up-down direction) than human beings. This is due to the asymmetrical positions of owl ears on either side of the head. The right ear is typically set higher in the skull and at a slightly different angle. By tilting or turning its head until the sound is the same in both ears, an owl can pinpoint both the horizontal and vertical direction of the sound's source.[6]

Prey can vary greatly based on opportunity. According to one author, "Almost any living creature that walks, crawls, flies, or swims, except the large mammals, is the great horned owl's legitimate prey".[20] The predominant prey group are small to medium-sized mammals such as hares and rabbits, which are statistically the most regular prey,[3] as well as any small to moderately sized rodent such as rats, squirrels, flying squirrels, mice, lemmings and voles. Other mammals eaten regularly can include shrews, bats, armadillos, muskrats, martens and weasels.[3][6] Studies have unsurprisingly indicated that mammals that are primarily nocturnal in activity, such as rabbits, shrews or muroid rodents, are generally preferred. Red-tailed Hawks (Buteo jamaicensis), sometimes considered a potential competitor to the Great Horned due to their overlapping range (in North America), habitat preferences and broadly similar (and similarly broad) prey selection, often focus their diet largely on the diurnally active squirrels.[21]

Sources and Credits

  1. (c) Minette, some rights reserved (CC BY-NC), http://www.flickr.com/photos/7232133@N08/2925340745
  2. (c) Joel Sartore, all rights reserved, uploaded by nataliemarisa, http://animals.nationalgeographic.com/animals/birds/great-horned-owl/
  3. Adapted by nataliemarisa from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Bubo_virginianus

More Info

Range Map

iNat Map

Taxa aves
Endangered status least concern