- Common Name
- great hornbill, great Indian hornbill, great pied hornbill, large pied hornbill, concave-casqued hornbill
- Genus Species
- Buceros (big horn) bicornis (two horns)
- The great horned owl is a large owl with ear tufts and barred feathers on the underside of its body. It has a bright white patch at the throat, which expands during vocalization.
- Approximately 45 to 63 cm (18 to 25 in.); wingspan up to 1.5 m (5ft.); females are usually larger than males
- Approximately 0.9 to 1.8 kg (2 to 4 lbs.)
- Animal prey including amphibians, reptiles, birds, and mammals; rodents are an important food source; can even take prey as large as skunks and grouse
- Approximately 32 days
- Clutch Size
- 2 to 3 eggs
- Sexual Maturity
- Approximately 2 years
- Life Span
- Ranging from 5 to 12 years, with occasional individuals living in excess of 20 years (particularly in zoological settings)
- Throughout North America, Central America, and South America; this species has widest distribution of any owl
- Found wooded and open areas
- Partners in Flight estimates the global breeding population at 6 million.
- IUCN: Least Concern
CITES: Appendix II
USFWS: Not listed
Great horned owls may be active during the day or night, but are mostly nocturnal. During the day they only cover about (2.6 km2) (1 mi2), so it is rare to spot them in daylight.
Less than 3% of all bird species are active at night, half of those are owls. Most owls have unique, comb like feathers that allow for silent flight. The leading edge is "fringed" so that the feathers, when moving, do not make noise when rubbing together. It is rare for the prey to hear an owl swooping in.
Great horned owls have the most identifiable call, which sounds like: 'who-who-who-who!'
If discovered during the day by small birds, it is not uncommon for the smaller birds to mob and chase away the owl.
It is a myth that owls can turn their head all the way around. Owls have 14 neck vertebrae, allowing them to move their head 270 degrees.
Although these birds have excellent eyesight, they are also capable of catching prey using only their sense of hearing. They have binocular vision and a hooked beak so as not to interfere with their vision. Owls' eyes look forward in a fixed position and cannot move from side to side, as the human eye can. In order to see peripherally, the owl must turn its entire head.
Researchers learn about the diet of owls by looking at castings, or pellets of indigestible material such as bones and fur that are regurgitated.
Owls are considered good luck in some cultures, but in others, they are feared as a sign of approaching death.
Great horned owls are one of the primary predators for skunks in North America. They have an opposable outer toe, which increases their ability to catch prey.
These owls do not build their own nest; rather they utilize an old nest of a hawk, eagle, or any other large bird species.
Ecology and Conservation
Great horned owls play important roles as predators throughout their range. Because they may hunt during the day or night, and take prey of various sizes and species, they have a large and widespread impact on small animal populations.
This species has suffered from habitat loss the most, then hunting, and illnesses linked to pesticide use.
Gotch, A.F. Birds - Their Latin Names Explained. Dorset: Blandford Press, 1981.
Martin, G. Birds by Night. London: T and AD Poyser, Ltd., 1990.
National Geography Society. 1983. Field Guide to the Birds of North America. 2nd ed. Washington, D.C.
Perrins, C.M. The Illustrated Encyclopedia of Birds. New York: Prentice Hall Press, 1990.
Peterson, R.T. Peterson Field Guide: Eastern Birds. Boston: Houghton Mifflin Co., 1980.
Hogle Zoo. www.hoglezoo.org/birds/hornowl.htm
allaboutbirds.org/guide/Great_Horned_Owl/lifehistory. Accessed 12 March 2020.