A young skunk shuffles from the foliage to sip from a rivulet—cool, refreshing. There’s a pleasant breeze along the water, damp and soft like spring. Late March breaks the buds on the trees. Stars flicker overhead in an immense firmament; a silver curve of the moon hovers in the western sky. The bank is bare and muddy in a dark landscape, pock-marked with the tracks of previous thirsty critters. Most animals would be wary around water holes—but a skunk has few predators, so worry dies at the hands of routine. Death by Routine. Tragedy strikes swiftly from above. The skunk struggles and sprays involuntarily as he’s snatched up and away by a silent and powerful force he’ll never live to see. As the great horned owl’s wings beat a silhouette against the sky, a group of raccoons watch with indifference, like feral dogs. Everybody’s got to eat.
Yes, who knew? One of the most aggressive and powerful predators in the forest is the great horned owl. He flies silently, attacks like a fighter plane, strikes with such force as to knock over his prey, and crushes backbones with huge talons and a 28-pound grip! Great horned owls can take down large prey including other raptors, such as hawks and smaller owls, geese, ducks, opossums, skunks, porcupines, rabbits, snakes—anything he can lift! With his long devil-like tufts, intimidating yellow-eyed stare, and a deep booming voice, he is the quintessential owl of storybooks, aptly nicknamed the “tiger owl.”
Adaptability is an asset if your survival is tested daily in the wild. Great horned owls are extremely creative with a vast range; they are the second most widely distributed owl in the Americas, just after the barn owl. In North America, they are the second-heaviest owl, after the closely related but very different-looking snowy owl. Great horned owls sport a wingspan from 3-5 feet and are heavily-built with a large head and barrel-shaped body. Females are slightly larger than males. Camouflage is near perfect. Underparts are usually light with some brown horizontal barring, upper parts generally mottled brown with heavy, complex, darker markings. Not only can you not hear them coming; looking up from the ground they’re hard to see! They have feathered legs and feet with dark gunmetal-gray beak and talons. The “ears” are actually tufts of feathers, called plumicorns, which have nothing to do with hearing.
Stealth and awareness favor the night hunter, and the great horned owl is top of his class. Tremendous hearing acuity comes from outer ear openings concealed by feathers on the sides of his head. These asymmetrically arranged ear holes allow for the triangulation of sounds when hunting in the dark. The owl can precisely locate prey by sound even if its hiding under cover of snow or brush. Of course, the owl’s night vision is legendary. In terms of size, the eyes dominate his face and rank proportionately among the largest eyes of all terrestrial vertebrates. He sees only black and white but can spot objects with about five percent the amount of light that a human requires, and his eyes are 35 times more sensitive. Rather than being round discs, his eyes are cylindrical. This puts more distance between the lens and retina, which gives a more “telephoto” effect for distance. Instead of turning his eyes like you and I do, the great horned owl turns his whole head, managing a neck rotation of almost 270 degrees. Combined, these awesome abilities deliver a wide, almost completely binocular, field of night vision. If it moves in the night and is edible—it’s fair game!
When one measures “wing loading,” or the size of the wings’ surface area to the bird’s weight, the owl has one of the proportionately highest ratings among raptors. This means tremendous lifting power. As for silent flight, he’s a trifecta of avian evolution. First, the leading edge of his feathers have serrations that disrupt turbulence caused by wing flapping; second, another layer below of softer feathers further deadens the sound, and finally, the trailing fringe of feathers cleans up any residual noise. Add in a wing structure that allows flight at very low speeds (2 mph when gliding with a breeze), and silence works like an invisibility cloak. As if nighttime was not already creepy enough, the haunting call of a great horned owl can lift the hairs on the back of your neck. Factor in the idea of a silent assassin and, for nocturnal mammals, you truly have a “tiger” who flies.
The opening paragraph alluded to the most infamous predatory association amongst any raptor and skunks. All skunks in North America (6 species) are reported as legitimate prey. Great horned owls are the only predators to routinely attack these repulsive mammals with impunity. Adult striped skunks can be as heavy as 3 times the weight of the attacking owl, yet in one single owl nest, no less than the remains of 57 striped skunks were found! It’s such a common meal that many owls’ nests reek of skunk. Hunting generally takes place from dusk to midnight, interrupted by a period of rest, and then can resume from late morning to sunrise. Forays generally include short flights from perch to perch, stopping to survey for food at each stop. From these vantage points, owls often dive down to the ground (with wings folded) to ambush their prey. As mentioned, they can also hunt by flying low and slow over openings in the forest, taking their prey from above. Kills are generally swallowed whole, bubbling up some 6-10 hours later as a regurgitation of pellets of bone and other non-digestible bits.
Great horned owls are not migratory and will mostly hang out in a territory year around. These personal borders are sacrosanct. They are maintained by vocal warnings first, without even seeing a competing owl—but the situation can turn physical in a heartbeat. It begins with the spreading of wings, beak-clapping, hissing, high pitched long-duration screams, and an imposing body posture threatening to strike. If an intrusion is pressed, the defender aggressively hops forward and strikes with its feet, grasping and raking as in a championship cock fight. Bird banders have had clothing torn or suffered severe lacerations working with these large, stocky birds. Most biologists banding great horned owls wear heavy jackets, gloves, and industrial hard hats. . . oh yeah!!
Great horned owls are not included in “birds of a feather.” In fact, he quickly becomes the elephant in a room. The relationship between great horned owls and other raptors is usually decidedly one-sided. While the red-tailed hawk and northern goshawk might be seen as potential competition, most others are merely regarded as prey by great horned owls. There is, however, sometimes safety in numbers. American Crows will often congregate to plot harassment raids against a lone great horned owl. The idea is to mob him and caw angrily at him for hours on end, until it becomes clear that leaving the area is his only source of peace. Depending on the degree of perceived threat, the owl is often pursued by the crows until virtually “run out of town.”
They say home is where the heart is, but great horned owls aren’t picky. Owl nests are usually high-rise affairs previously owned by some other big bird; could be hawk, eagle, crow, or heron. They may add a few feathers from time to time, but that’s about all. They will sometimes choose a cave or cliff ledge, or even a hollowed-out tree trunk. The main requirements are that living quarters be high and sturdy. Owls living in prairie country, in the absence of other options, will use boulders, buttes, railroad cuts, low bushes, and even the bare ground as nest sites.
The great horned owl is one of the earliest nesting birds in all of North America, often laying eggs weeks or even months before other raptorial birds. Courtship is a rather simple affair. The male performs some display flight and feeds the female—that’s all it takes to score. Eggs are incubated mostly by the female but once there are chicks, both birds participate in the care and feeding of babies. The young will be fed up to several months after hatching, and may leave the nest to climb on nearby branches at around 5 weeks—but are flying at about 9-10 weeks. Breeding pairs usually mate for life.
The great horned owl knows his purpose and is exquisitely prepared to fulfill it. For him, there is no mystery to life. Mankind has long envied owls. From ancient Babylon and the Greek goddess Athena to Harry Potter’s Hedwig, owls are woven into the fabric of human culture. There’s something about their unblinking stare and nocturnal lifestyle that mesmerizes. At times owls are depicted as dignified, wise old scholars and at other times enigmatic beings who see all—omens of both good and evil. Beautiful, silent, and a pitiless predator, the great horned owl is intimately in touch with his true self.
By Larry Gfeller