by Geoffrey Carpentier
If you ask anyone what sound an owl makes, they will likely respond “hoo-hoo” in a deep, resonant voice. However, most owls do not make this sound at all but use barks, screeches, screams, whistles and more, to announce their presence and intentions. Yet the Great Horned Owl, likely our most common local owl species, does use a medley of hoots, to call a mate and to proclaim territory. Although the male is smaller than the female, he has a larger voice box, so he produces deeper hoots, while hers are higher pitched. The female generally hoots 6-7 times in response to the male’s five hoots, so the sexing of the birds, when heard well, can often be determined fairly easily.
The owl’s name is derived from the two feather tufts which look like ears, on the top of the head. They are, however, not ears at all but simply feathers, called plumicorns, which can be raised or lowered to suit the mood and needs of the owl. Their purpose is uncertain, but some scientists speculate they can be used as a means of identification between individual owls.
This is the time of year these large owls (body length ~0.7 meters and wingspan ~1.5 meters) start to nest. Unlike many large birds of prey, they don’t build their own nest but commandeer another large stick nest built previously by a hawk or crow. They sometimes embellish the nest by adding bark, some of their own feathers, or even the pellets they eject after having dinner. The male chooses the nest site and most commonly uses whatever site is available, including cavities in trees and snags, cliff ledges, deserted buildings, artificial platforms, and sometimes even directly on the ground.
In our area, the first eggs can be laid as early as January 29th and as late as mid-May, so it is a protracted breeding season. One to two, sometimes up to five eggs are laid, with the first being the largest. This is a survival strategy whereby this egg, being larger, can produce a slightly larger baby, consequently enhancing its ability to thrive at the expense of its siblings. This is enhanced even further as the female owl starts to incubate the egg immediately, again increasing the young owl’s ability to compete. After about 4-5 weeks, the eggs hatch, just in time to take advantage of prey, which will feed the young birds. Six to seven weeks later, the young leave the nest, after increasing their body weight 23 to 28 times their hatching weight!
The Great Horned Owl will eat a variety of food, from small avian and mammalian prey to large birds of prey, such as osprey and other owls. In addition, it will eat snakes, scorpions, reptiles, amphibians, insects, Great Blue Herons and waterfowl. They certainly are opportunistic feeders.
Their hunting abilities are unbeatable, as they can hear and see prey better than many other predators. It’s hard for us to comprehend their abilities, as our senses are so poorly developed compared to theirs. They can see a mouse from as far away as 1.6 km. They only see in black and white but their vision is 35 times more sensitive than ours, to light. They can detect prey under low-light conditions 20 times better than we can. All this is enhanced further by the shape of their face, which acts like a parabolic mike to magnify sounds.
As I’ve written in the past, they sport soft feathers which insulate them against the cold winter weather and help them fly quietly, in pursuit of prey. Their short, wide wings allow them to manoeuvre silently among the trees of the forest. Their eyes don’t move in their sockets, but they can swivel their heads more than 180 degrees, to look in any direction.
One last thing: do they mate for life? Well, probably not, but they certainly are faithful to their spouses and can, on average, stay with their mates for at least five years.
Correction: in a previous column (January 9th, 2025 – Baby It’s Cold Out There), I said a chickadee keeps its core body temperature at 105C; it should have been 105F – oops.
Geoff Carpentier is a published author, expedition guide and environmental consultant. Visit Geoff on-line on LinkedIn, Facebook and Instagram.
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