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Great Horned Owl with chicks

Bubo virginianus

Description:

Great Horned Owls range in length from 18–27 in (46–69 cm) and have a wingspan of 40–60.5 in (101–153 cm); Females are larger than males, an average adult being 22 in (55 cm) long with a 49 in (124 cm) wingspan and weighing about 3.1 lbs (1400 g). Depending on subspecies, Great Horned Owls can weigh from 0.72 to 2.55 kg (1.6 to 5.6 lb).[1] Adults have large ear tufts, a reddish, brown or gray face and a white patch on the throat. The iris is yellow, except the amber-eyed South American Great Horned Owl (B. V. nacurutu). Its "horns" are neither ears nor horns, simply tufts of feathers. The underparts are light with brown barring; the upper parts are mottled brown. The legs and feet are covered in feathers up to the talons. There are individual and regional variations in color; birds from the sub-Arctic are a washed-out, light-buff color, while those from Central America can be a dark chocolate brown. Their call is a low-pitched but loud ho-ho-hoo hoo hoo; sometimes it is only four syllables instead of five. The female's call is higher and rises in pitch at the end of the call. Young owls make hissing or screeching sounds that are often confused with the calls of Barn Owls.

Habitat:

Nest in the crook of a pine tree along San Francisco Bay

Notes:

Great Horned Owls are some of the earliest-breeding birds in North America. They breed in late January or early February and are often heard calling to each other in the fall, starting in October. They choose a mate by December and are often heard duetting before this time. For owls found in more tropical climates, the dates of the breeding season are somewhat undefined. They often take over a nest used by some other large bird, sometimes adding feathers to line the nest but usually not much more. Old crow and raven (Corvus), Red-tailed Hawk (Buteo jamaicensis) or large squirrel nests are often favored in North America. However, they are far from dependent on the old nests of others and may use cavities in trees and snags, cliffs, deserted buildings, and artificial platforms. There are usually 2 eggs per clutch, with a clutch ranging in size from 1 to 5 eggs (5 is very rare). The average egg width is 1.8 in (46.5 mm), the average length is 2.2 in (55.2 mm) and the average weight is 1.8 oz (51 g). The incubation period ranges from 30 to 37 days, averaging 33 days. Brooding is almost continuous until the offspring are about 2 weeks old, after which it decreases. Young owls move onto nearby branches at 6 weeks and start to fly about a week later. The offspring have still been seen begging for food in late October (5 months after leaving the nest) and most do not separate from their parents until right before they start to reproduce for the next clutch (usually December). Birds may not breed for another year or two, and are often vagrants ("floaters") until they establish their own territories.

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1 Comment

ChristyHolland
ChristyHolland 11 years ago

Nice capture!! What a nest!! That one doesn't look like it'll come down in a storm!! Mom doesn't look very worried about you being there! Great series, Donna!

DonnaPomeroy
Spotted by
DonnaPomeroy

Fremont, California, USA

Spotted on Apr 28, 2012
Submitted on Apr 29, 2012

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Reference

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