Friday, July 27, 2012

Great Horned Owl

Great Horned Owl, Bubo virginianus
One of the most widespread and common owls in North America, and found throughout a great portion of South America, the Great Horned Owl is also one of the most recognized owl calls. The scientific name, Bubo virginianus, was gained from the first sighting in the Virginia colonies. The common name was obtained from the tufts of feathers that give a horn-like appearance. With a wingspan of just under 1.5m, and length at 0.5m, the great horned owl is an impressive size. Like many other raptors, the female is larger than the male. Their diet is broad, eating anything that moves and can be caught.

Fresh caught prey for the young to feed on.
Among the prey are invertebrates, mice, snakes, skunks, Virginian opossum, herons. Even other raptorial birds can call prey to the horned owl; including nestlings of ospreys and Mississippi kites, owls such as the screech owl, and falcons like the peregrine falcon. While the great horned owl usually hunt from a perch on a clearing edge, they have been observed to also walk on and turn over forest floor litter and wade in shallow water. The adult great horned owl has no natural predators although harassment by red-tailed hawks and crows especially are not uncommon. In retaliation, the owls often attack roosting groups of crows and kill many.

Nest in current use by mated Great Horned Owls.
The nests of the great horned owl are either previously built by other species, such as the red-tailed hawk and pileated woodpecker, or artificial when suitable natural nests are unavailable. The territory often does not change between seasons, but the nest will. Hostility and extreme aggression is common when young are still in the nest. After an incubation of close to a month, the young hatch by mid-February, roam the nest close to the beginning of April, and can fly decently by May.

Both parents equal help raise the young.
The weaning has the young in the nest for another few weeks before they finally leave the nest and territory by fall. The mated pair maintain their joint territory all year, but will only stay together during nesting season. The great horned owl may live close to 13 years in the wild, but in captivity may live closer to 40 years.

2 comments:

  1. I read in the newspaper that crows move into cities in the winter because the owls come out of the woods and are more likely to catch crows. And a sure sign that spring is coming (but not yet here) is when the crows return. I know the crows go and people in Burlington say that it seems all Vermont crows go spend the winter there (they are the largest city, even tho Montreal is closer, but I don't know what Montreal experiences with the crows). This was a great post.

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    1. That I didn't know. Huh, makes sense to me though especially as I imagine food may be a bit more scarce during winter so the crows may be in more danger? Speculation. Thanks for the tid bit!

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