Great horned owls breed in every county in New Hampshire, and their breeding season is now underway. From late December into March, male and female owls will be calling to each other in the night as they pair up to begin nest-building in late January. The call of the great horned owl is the one that is used in movies to represent “an owl” in much the same way that the cry of a red-wing hawk represents “a hawk.” The male produces a series of five or six deep stuttering hoots that can carry for over a mile. The female’s hoots are higher pitched but have the same rhythm as the male’s.
In addition to having the classic owl voice, great horned owls have the classic owl look. Unlike the more common barred owl, the great horned has prominent ear tufts and bright yellow eyes. These large owls are about two feet tall — the females are much larger than the males, which is typical among raptors — and have a wingspan of nearly four feet.
The combination of the ear tufts, its size, reddish brown facial disks, and a broad white patch on its throat make the great horned owl hard to mistake for any other bird. The white patch is variable in shape and size and may extend down the middle of the chest. Most of its body is covered with feathers that are finely barred with black, brown, rufous, and white. Even the legs and feet are feathered. Throughout its wide range its overall color — including the facial discs — varies greatly from sooty through reddish-brown to pale gray or buff.
The “Atlas of Breeding Birds in New Hampshire” gives a thorough description of the mating and nesting behavior of this species. After some synchronous hooting, the courtship can begin. “The male bows his head, raises his spread wings, and dances along a limb or hops from branch to branch, snapping his bill loudly. Eventually he approaches the female and strokes her, rubbing bills and bowing (Bendire, 1892; Braillat, 1922 in Bent, 1938).”
This owl has a reputation as a tough customer. They may defend their nests with divebombing swoops and occasionally outright attacks that may injure the intruder, including humans.
The intensity of the defense escalates as the investment in the young proceeds. Eggs are laid — normally two — in February and are incubated 28 to 35 days. The eggs are commonly laid several days apart. The female remains on or near the nest during the incubation and brooding while the male does all the hunting.
Owlets venture outside the nest after five or six weeks and may attempt short flights, but will not fly well until they are at least nine weeks old. It has been reported that they have the habit of destroying the nest when the young fledge, thus eliminating readily visible evidence of the young’s presence and allowing their natural camouflage to protect them. The parents continue to feed the young through the summer, and they disperse in the fall.
Great horned owls do not build their own nests or excavate their own nesting holes. Instead, they re-use a nest that has been abandoned by crows, squirrels, great blue herons, red-shouldered or red-tailed hawks. These owls will also nest anywhere that can accommodate them, including ledges, large cavities, and broken-off tree trunks. Near the northern limit of their range at the boundary of the taiga and the tundra, they may nest on the ground.
Great horned owls are said to occupy night shift in the same habitat as red-tailed hawks, which is to say woodlots at the edge of large open spaces. They are, however, even more widespread, ranging not only throughout all of North and Central America, but also into the whole of South America.
As might be expected from a large, fierce predator that lives almost everywhere, they eat almost anything, including rodents, rabbits, birds, skunks, and occasionally porcupines. They don’t stop at mammals, but will also prey on reptiles, amphibians, birds (including domestic chickens), and invertebrates as well. They hunt mostly at dusk and dawn, but may remain active in the evening until midnight.
Their talons are huge and powerful, extending in a fully spread foot across nearly 9 inches. By comparison, the even larger great gray owl has a talon spread of a little over 7 inches. The crushing power of the feet is 300-500 pounds per square inch. In some larger female owls, the crushing power may approach that of the much larger golden eagle, which can range over 800 pounds per square inch. By comparison, the average human hand can manage about 20 pounds per square inch.
With its large size, silent flight, rapacious feeding habits, and deadly hunting equipment, the great horned owl earns its nickname: “tiger of the air.”