Raptor Rehabilitation
of Kentucky

RANGE: North and South America, from the Arctic to Straits of Magellan, except the West Indies.

HABITAT: Varied, from forests, deserts, open country and swamps to city parks.

SIZE: Length: 18-26 inches Wingspan: 49-62 inches Weight: 2-5 pounds

LIFE EXPECTANCY: WILD: 15-20 years CAPTIVITY: 25-30 years

REPRODUCTION: Owls in general are terrible nest builders. Because the GHO is extremely aggressive, they are notorious nest stealers, driving off red-tails and even eagles. They also nest in natural cavities or just in the crook of a tree. In this area the GHO breeds in December and has eggs in the nest by January. The incubation period is 26-35 days. They are always the first raptor to have young in the nest, and this means that GHO chicks will have an advantage over other young raptors because they have more time to practice hunting before the winter comes. The chick's eyes open around day 10, they venture out of the nest and become "branchers" at 5-6 weeks old. They fly short distances at 6.5 weeks and are proficient fliers at 10-12 weeks of age. They stay with the parents until early summer and continue to roost and hunt in their parents’ home range until the fall when they are forced to leave.

DIET: WILD: Anything that they can carry off (up to 3x the weight of the bird): from insects and scorpions to domestic cats and woodchucks, can take birds as large as geese and herons. CAPTIVITY: Chicks, rats, mice, rabbits, and squirrels.

BEHAVIOR: GHOs are extremely aggressive hunters, known as the "tigers of the sky". They have been known to attack duck decoys. When there is plenty to eat they will pick out the choicest parts of prey and then hide the rest. The male GHO has a 5 note call, the female has a 7 note deeper pitched call. These are non-migratory birds in general, but the northern most factions will move south if prey becomes scarce. They are usually a nocturnal hunter, but they will hunt on a cool, overcast day or on a sunny day if feeding young. In courtship displays, both sexes hoot while bowing, lowering wings and raising tail simultaneously.

POINTS OF INTEREST: The GHO is the nocturnal counterpart of Red-tailed hawk; they prefer the same types of prey and habitat.

The GHO is the largest of the tufted owls and the heaviest owl in North America. In overall size it is second only to the Snowy Owl.

GHOs have no natural enemies except man.

Plumicorns: The Plumicorns (ear tufts) are only feathers and have nothing to do with hearing. Their function is to show expression, like our eyebrows. The ear tufts allow them to look larger and more threatening when showing aggression. They also serve to lengthen the owl when it sits against the trunk of a tree so that it blends in and resembles a bulge on the tree.

Eyes: The eyes of the Great Horned Owl are the same size as a human’s. If a human being had eyes in its head to compare to a GHO’s, our eyes would be the size of grapefruits and weigh five pounds apiece. They are barrel shaped and go deep into their head, occupying about 50% of their skull. GHOs also have more rods (light receiving cells) in their eyes than a human and can hunt from the equivalent to the light of a single birthday candle 3-4 football fields away. In addition to their phenomenal night vision, GHOs also see well during the day. They are reported to be able to see birds flying overhead during the day that people cannot see with the aid of binoculars. However, they cannot clearly see objects that are closer than 3 feet. Their eyes have few cones (color receiving cells), and therefore they see mostly shades of gray.

Ears: GHOs have ears symmetrically placed on the edge of the facial disc behind the eyes. They are covered by flaps of skin that they can open and close at will, and the facial disk is fringed with short, stiff feathers that gather and amplify sounds. This aids them in pinpointing the location of prey by sound.

Talons: The talons of the GHO are the most feared of all of the raptors’. Each of their feet is capable of exerting 500 pounds of pressure per square inch, which would be enough to crush a human skull if their feet were able to go around it. It is with the feet that the GHO kills its prey, simultaneously puncturing the animal with its razor sharp talons and crushing the animal with its grip, causing massive internal injuries. Their legs are also equipped with a locking mechanism that prevents them from releasing their prey until their legs straighten.

Plumage: They have what is called cryptic coloration, a mottled coloration that allows them to blend in with their surroundings. They are all shades of brown and gray with white feathers under the chin. Their flight feathers on the wings are barbed, these barbs don't interlock and this allows the air to pass through them. When combined with a tiny fringe along the leading edge of the wings, the GHO is able to fly silently.

Hunting: GHOs are primarily perch-and-pounce hunters. They generally have a favorite perch where they will sit and wait for prey animals to pass underneath of them. When prey is spotted they dive silently after it, and the animal generally never knows what happened. GHOs have been known to walk into chicken coops after dark and kill several chickens, eating only the heads. Often the Red-tailed hawk is blamed for this. They are also known to wade chest-deep into streams and catch fish in their talons.

STATUS: This is a common raptor. Its ecological adaptability and secretive nature aid its success despite persecution.