The Great Horned Owl (Part 2)
Description
Although it is called 'horned' owls, it is, in fact don't have a horn. It is an earlike tufts of feathers, called plumicorns. The function of plumicorns itself are not quite clear, but it is a theory that it might function as a visual cue in territorial and socio-sexual interactions with other owls.
Great Horned Owls are nocturnal birds. They have big eyes and wide pupils that allow them to spot their prey. Unlike people’s eyes, their eyes don’t move in their sockets, but the owls can swivel their heads to look in any direction.
The Great Horned Owl is generally coloured for camouflage, in another word, their main colour vary in each region. The underparts of the species are usually light with some brown horizontal barring; the upper parts and upper wings are generally a mottled brown usually bearing heavy, complex darker markings. All subspecies are darkly barred to some extent along the sides as well. Tarsi and toes are densely feathered, with just a small zone at the end of the toes bare, and coloured greyish-brown. Claws are dark horn with blackish tips. All great horned owls have a facial disc. This can be reddish, brown or gray in color (depending on geographical and racial variation) and is demarked by a dark rim culminating in bold, blackish side brackets.
As for their size, they are 45 until 60cm long in length with their tail length 175-250mm. Their wingspan is about a 100cm long and they weigh about 1,5kg. The female owls are suprisingly larger than males for about 10-20%.
Behavior and habits
The Great Horned Owl's activity generally begins at dusk, but in some regions, may be seen in late afternoon or early morning. Both sexes may be very aggressive towards intruders when nesting. They have a large repertoire of sounds, ranging from deep booming hoots to shrill shrieks. The male's resonant territorial call can be heard over several kilometres during a still night. Both sexes hoot, but males have a lower-pitched voice than females. They uses this hoot to advertise its territory. It can also make a variety of other sounds, including whistles, barks, shrieks, hisses, coos, and wavering cries. Most calling occurs from dusk to about midnight and then again just before dawn.
Great Horned Owls hunt by perching on snags and poles and watching for prey, or by gliding slowly above the ground. From high perches they dive down to the ground with wings folded, before snatching prey. Prey are usually killed instantly when grasped by its large talons. They also hunt by walking on the ground to capture small prey or wading into water to snatch frogs and fish. They have been known to walk into chicken coops to take domestic fowl. Rodents and small rabbits can be swallowed whole while larger prey are carried off and ripped apart at feeding perches or at the nest. Birds are often plucked first, and legs and wing tips discarded. An extremely wide range of prey species (over 250 identified) are captured, but rabbits and hares are its preferred prey. Mammalian prey includes all coexisting rodents, squirrels, mink, skunks, raccoons, armadillos, porcupines, shrews, moles, muskrats, and bats. A Great Horned Owl is powerful enough to take prey 2 to 3 times heavier than itself.
QUESTIONS
1. Which order does the Great Horned Owl belong to?
a. Strigiformes
b. Strigidae
c. Gnathostomata
d. Aves
e. Bubo
2. How long is the lifespan of the wild great horned owls?
a. 33 years
b. 30 years
c. 13 years
d. 31 years
e. 17 years
3. One of the great horned owl natural enemy is
a. Hummingbird
b. Crow
c. Heron
d. Peregrine Falcon
e. Snowy white owl
4. The Great Horned Owl is native to
a. South America
b. Central America
c. Northwest Asia
d. North America
e. Subarctic region
5. Which of the following is the correct fact about the great horned owl?
a. The great horned owl can only live in subarctic region
b. The males are bigger than the females
c. One of great horned owl's natural enemy is Northern Goshawk
d. The great horned owls live in groups
e. They all have the same colour of feathers
Sources:
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