You might have heard a pair calling back and forth in early January which is when they typically begin courtship. Their deep “hoot hoot” call is the classic owl call that everyone recognizes.
Great-horned owls like many other owls don’t make their own nests but rather adopt old stick nests made by other raptors, squirrels, or they nest in big tree cavities or snags.
The female typically starts laying her eggs in mid-February, often when there is still snow on the ground and sub-zero temperatures. The female lays on average between 1-4 eggs and incubates the eggs for 32-35 days before they hatch. The number of eggs laid each year has been shown to correlate with the availability of their main prey, which is small mammals.
Raising Great-horned owlets is no small feat, and it takes about 2.5-3 months after hatching before the young ones are able to fly. Like any predator, the young ones need to learn how to hunt and capture their own prey, so even though they are able to fly at 3 months, they are still dependent on their parents for food while they slowly acquire hunting skills. As the young ones become more independent and capable of capturing their own prey they will leave the parents’ territory and find their home, this usually happens in early- to mid-fall.
The oldest free living Great-horned owl documented was 27 years and 7 months!
Check out this webcam of a Great-horned owl nesting site from the Owl Research Institute in Carlo, Montana. The owls are around but they haven’t started nesting yet. They typically start mid-February and you can hear the owls calling at night.