I love owls; they’re one of my favorite animals (up there with foxes and wolves). I even have a set of owls that I cross stitched hanging on the wall in my bedroom.
And honestly, what’s not to like about owls? They’re so cool! They have asymmetrical ears, which helps them better pinpoint the location of their prey. They can rotate their necks 270 degrees (which could be a problem if blood vessels in the neck get pinched off, but owls have solved this issue by having larger blood vessels at the base of their head that form blood reservoirs to continue blood flow to their brain and eyes). They have zygodactyl feet, which means two toes point towards the front and two towards the back. A group of owls is called a parliament. I even once had an owl mess with my field work in grad school! One ate one of my vole subjects; we know because we found the vole’s radio collar in a pellet a few days later.
Today I want to introduce you to the owl you are most likely to run into if you live in the Americas: the Great Horned Owl, Bubo virginianus.
- Found all over the Americas
- Great Horned Owls are the most widely distributed true owl in the Americas and one of the most common owls in North America. Part of its large range and distribution is because it is so adaptable: you’ll find them in deserts, wetlands, forests, grasslands, and cities. Basically take anywhere that is semi-open, and there’s a good chance you’ll find a Great Horned Owl in it. But just because you can find a Great Horned Owl in all of these habitats doesn’t mean they always look the same. There are more than 20 subspecies of Great Horned Owls, although many of these “subspecies” are just geographical variations in coloration. Subarctic individuals tend to be lighter in color, for instance, while those on the Pacific Coast and in Central America are a dark brown. These variations in coloration help each owl blend in with their specific habitat.
- Big Bird
- One way to recognize a Great Horned Owl is by their size: they can be very very big. Adults range in body size from 17 to 25 inches, with the average being 22 inches. And that’s just their body – their wingspan is an average 48 inches. Great Horned Owl size varies due to location and sex. Those living in Alaska tend to be the largest, and those in California and Texas lean towards the smaller size. Females are also typically bigger than males (we’re talking a weight of 3.5 lbs in females and 2.7 lbs in males).
- Owl anatomy
- In addition to their size, Great Horned Owls are identifiable by the “horns” on the sides of their head, called plumicorns. These plumicorns are just tufts of feathers; they seem to serve no purpose in hearing and are instead hypothesized to serve as signals in social interactions. Their actual ears are openings found on the sides of their head.
- Great Horned Owls (like most owls) also have a facial disk. This is the concave collection of feathers on their face that funnels sound to their ears; the specific color of this facial disk depends on the Great Horned Owl’s geographic location. Inside of their face (obviously) are the Great Horned Owl’s eyes. These eyes are HUGE, even for an owl – they’re only slightly smaller than our eyes and are proportionally among the largest eyes of any terrestrial vertebrate. Like all owls, these eyes can’t move inside of their head. That’s why owls need to turn their entire head to look around: they literally can’t look from side-to-side without moving their head.
- Lots of things to hunt
- The size of Great Horned Owls is beneficial for hunting; these large birds can basically hunt anything. Prey species range from what you may think as “typical” owl food (mice, voles, rabbits, squirrels, and snakes) to larger animals like raptors and porcupines. Skunks are also on the menu; like most birds, Great Horned Owls have a poor sense of smell, so they don’t mind the scent attacks of skunks. They are able to hunt larger prey because of the strength in their talons, which can sever an animal’s spine. Most times, though, prey is simply killed by being crushed by the owl’s feet or stabbed with their talons.
- Home for life
- Unlike other owls (snowy owls, norther saw-whet owls, long-eared owls), Great Horned Owls are sedentary and do not migrate. These large birds need an equally large territory, although the exact size depends in part on how much prey it contains. Territories in the Yukon, for instance, are an average of 6.2 square miles, while Wyoming territories are only an average of 0.81 square miles. Each territory typically contains a single mated pair. The male in the pair does most of the territorial defense, although the female will help out during hooting contests. Once their territory is established, most Great Horned Owls will stay on that territory for their entire life. Young Great Horned Owls also don’t typically move that far from their natal nest – over 90% of nestlings have been found less than 80 km from where they were born.
- One of the earliest nesting birds
- Pairs of Great Horned Owls are (for the most part) monogamous. The male will attract his mate in the late fall or early winter, and they will begin laying eggs early in the year. In northern climates, this happens even before the snow has melted! Eggs are incubated for about a month, and the young start to fly at 3 months old. Once their young have become more independent, the breeding pair may start to spend less time with each other. However, they will typically rekindle their bond when the next breeding season begins.
There you go. Great Horned Owls, one of the biggest owls in America, and one I hope I will have a chance to see in my backyard. Let me know if you ever see one yourself!
P.S. The idea for this post was suggested to me; feel free to reach out if there is an animal you wish to know more about!