As January temperatures dip into single digits and heavy snow and wind howl across the countryside, the first nesting bird of the year sits tightly on its eggs. When the storm finally relents, a snowy blob is revealed. It slowly shakes its head, revealing two vertical feather tufts, then gently rises, allowing the snow to carefully slide off to its sides. It bends its head down to check that its eggs are safe and quickly settles back down to resume incubation. Is it any surprise that the great horned owl (Bubo virginianus), is one of our fiercest and toughest predators?
The great horned owl is one of the most common owls in North America. Unlike the loud “who-cooks-for-you” call of the barred owl or the whinnying trill of the tiny Eastern screech owl, the great horned owl is our only true “hoot” owl. During mating season in autumn, its signature deep, soft hoots, “hoo, hoo-hoo”, can be heard in the darkness. By the time December rolls around, pairs have been formed and nest sites chosen.
Great horned owls do not build their own nests, rather, they prefer to use those constructed by other species. Bald eagle and red-tailed hawk nests are often preferred, but the owls will also utilize large cavities, snags or even abandoned buildings. By mid-January, one to four eggs have been laid and an incubation lasting up to 37 days ensues.
A fierce predator
The great horned owl is truly impressive. Standing at a height of 25 inches and sporting a wingspan of 5 feet, this predator is at the top of its nocturnal food chain. Known as the “winged tiger”, it is fierce and powerful, procuring a wide variety of prey items. With the most diverse diet of any raptor, this owl will prey on items as small as invertebrates and rodents up to prey even larger than itself. It is also the primary predator of screech and barred owls, which remain silent in its presence. It is interesting to note that the great horned owl’s favorite meal is striped skunk. Owls lack a sense of smell and a skunk’s obvious color pattern makes it easily visible in the dark and one of the top items on this owl’s menu.
When an owl has digested everything that it possibly can from a meal, its stomach acts as a trash compactor, squeezing all the remaining contents tightly together into a hard pellet. This mass of undigested parts often contains fur, bones, insect exoskeletons, feathers, claws and teeth. The owl then brings the pellet up through its mouth, regurgitating it to make room for the next meal. Owls are not the only species to produce pellets, many species of hawks, crows and even songbirds will cough up the remains of meals. Pellets are odorless and dry quickly. Many a class of school children have been awed by the contents of these pellets when dissected as a science project.
It is easy to mistake the “horns” arising from the great horned owl’s head, for its ears. These, however, are only feather tufts that allow it to better camouflage itself among leaves and branches. An owl’s ears are actually located below its eyes inside a feathery facial disc which helps to funnel sound, much like a satellite dish. Although their golden eyes are set stationary in their sockets, an owl can swivel its head more than 180 degrees to see in any direction. The fringe along the trailing edge of its wing feathers allows for completely silent flight, while powerful talons, capable of exerting a force of up to 500 pounds per square inch, round out the owl’s superior collection of unique characteristics.
In the wild
In the winter of 2020, I checked a local bald eagle nest for activity and was elated to discover the silhouette of a great horned owl sitting on the edge. Needless to say, I made many trips back in hopes of getting a glimpse of the growing owlets. Both parents are devoted to their chicks, providing them with a constant supply of food. The youngsters grow quickly and by five weeks of age are venturing out onto nearby limbs. By nine to 10 weeks, they are beginning to stretch their wings in flight. During this time of fledging, the youngsters depart the nest for good. They will remain in their parent’s care learning how to hunt for several months thereafter. I was able to observe two owlets in the old bald eagle nest as they grew and became more and more confident, jumping from limb to limb while stretching their wings. I knew fledging was near and had mixed feelings when I arrived one day to find the entire family gone.
It is interesting to note that the oldest great horned owl on record was at least 28 years old when it was captured in Ohio in 2005. Great horned owls are often seen as symbols of intelligence and wisdom. Perhaps this is because they are one of the most adaptable and widespread owl species. One thing for sure is that as far as nesting goes, the great horned owl is, without a doubt, the first.
This was so interesting. I learn things I didn’t know about the wildlife I love when I read your column. Thank you.
Brilliant love these birds of prey so much cheers x
I called a female in in front of my house last evening she sat and looked everywhere for the male FYI from my smart phone app there’s a pair here I can hear them every evening calling she was beautiful and majestic awe inspiring I love birds I feed them everyday I go to Ace hardware once a week and buy food to put on the fence in front of my place and Los Altos hills California.