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Coincidentally, the great horned owl nesting offers a rather exciting insight into the diversity of behaviors and adaptations. An article such as this one considers different types of sites for nesting and the fascinating nest takeover behavior. It also explores cavity nesting in trees, unusual locations, and how these magnificent birds adapt to cities.
To that end, read this extensive primer on great horned owl nesting to enhance your knowledge with a proper appreciation for their amazing survival strategies in both wild and urban environments.
Table Of Contents
Key Takeaways
- Great horned owls are real estate opportunists, often taking over nests built by other birds or using natural structures like cliffs and abandoned buildings.
- They’re like the ultimate home renovators, adapting their nests to suit their needs, from adding new twigs to discarding debris to keep things tidy.
- They’re surprisingly adaptable to urban environments, finding nesting spots in parks and green spaces, and even using human-made structures like bridges and buildings.
- These owls are like the ultimate "cool parents," incubating their eggs during winter and hunting for food to feed their young for months after they leave the nest.
Nesting Site Varieties
The Great Horned Owls are most accommodating when it comes to nest site selection. They don’t build their own nests; instead, they take over an old one that has been previously used by other large birds or use natural structures.
Abandoned hawk or crow nests, tree cavities, cliffs, and even man-made structures seem to be favorite choices. Nest size and shape will vary, but they’re usually reasonably roomy and fairly sturdy. Nest height and exposure vary with habitat; you might find one 60 feet up a tree or tucked into a sheltered cliff ledge.
Unlike some birds, Great Horned Owls don’t mind nesting close to human activity as long as they have enough food nearby. While they don’t seem to care much about the distance from other nests, they’re fairly territorial and tend to be interested in known food supplies.
Takeover Behavior of Nests
From the great variability of Great Horned Owl nesting sites, turn now to their behavior of taking over a site. You’ll find it most interesting. Great Horned Owls are highly aggressive and will often usurp a nest from another raptor. Their timing is excellent; they tend to initiate takeovers when competition is most fierce during the early breeding season.
In particular, the behavior resembles kleptoparasitism, where one species usurps another species’ resources. Notable elements for this sort of rogue nesting behavior are as follows:
- Displacement: Great Horned Owls will easily use the nests of Red-tailed Hawks, Crows, and even squirrels.
- Aggressive Tactics: Using their physical prowess to overpower and expel current nest occupants.
- Strategic Timing: Pairs select nesting sites when the breeding season commences, thus conditions are most suitable for raising young.
Tree Cavity Nesting
Great horned owls are cavity nesters. They don’t build their own nests but appropriate those from other birds. They also appropriate nests from hawks, crows, ospreys, squirrels, plus even bald eagles. They seem to favor red-tailed hawk nests usually in the crotch of a tree and 40-70 feet above the ground.
The owls don’t repair the nest, and eggs or young may fall through holes in badly deteriorated nests. They’re good parents, however, continuing to feed their young for several months after they’ve left the nest.
Great horned owls are strongly territorial. Nest sites are vigorously defended against other owls and hawks, as well as against other great horned owls not part of the pair. Their territories range in size from one-third to two square miles.
Most owls start searching for nest sites in September. Courtship occurs in December and January. Female great horned owls normally lay two eggs, although incubation is the female’s sole responsibility. When a female lays an egg she immediately starts incubating it. So with the regular laying of two eggs, one may well be as much as several weeks bigger than its sibling.
Nesting is a winter activity, with females incubating the eggs while males hunt for food alone. Owlets, as the baby owls are known, arrive about the size of baby chickens and grow fast; their diet usually includes rabbits, mice, hawks, crows, fish, and even skunks. By three months, they’re normally fledged.
Great horned owls have adapted to cold temperatures; nests have been found as low as -20°F (-28.9°C).
Unconventional Nesting Locations
Building on their preference for tree cavities, Great Horned Owls also choose unconventional nesting locations. Sometimes, they adapt surprising places:
- Cliff edges: Though risky, cliff nests offer safety from ground predators.
- Old, large bird nests: Reusing existing nests, they adopt minimal nest scraping and augment with new twigs.
- Man-made structures: Abandoned buildings, hunting stands, or platforms provide excellent support.
- Ground-level sites: Rarely, owls nest on the ground in sheltered spots if no better options exist.
They practice egg adoption if they find abandoned eggs and maintain nest sanitation by discarding debris. For nest cooling, they choose locations with natural shade, keeping their eggs safe from excessive heat.
Urban Nesting Adaptation
Great Horned Owls adapt to urban environments by nesting on human-made structures such as buildings and bridges, which offer benefits like fewer predators and increased nesting opportunities. However, urban nesting comes with challenges such as noise impacts and light pollution that can disturb their natural behaviors. Despite these difficulties, owls exhibit remarkable adaptability. For instance, nest box programs can provide safer nesting spots, mitigating some urban challenges. Additionally, human-made structures often offer elevated vantage points, aiding in predator avoidance. Surprisingly, they thrive in parks and green spaces within cities, balancing the need for habitat with human presence. Understanding these adaptations is key to promoting coexistence and ensuring the owls’ future in increasingly urbanized landscapes.
Frequently Asked Questions (FAQs)
When do great horned owls lay eggs?
Great horned owls typically lay their eggs in late winter or early spring, with clutches of 1-3 eggs. The exact timing can vary based on location and environmental conditions.
How long is the fledgling period?
The fledgling period for Great Horned Owls lasts about six weeks when they leave the nest to walk around, and it another three weeks for them to learn to fly (Source).
What materials line the nest?
Ah, the age-old question of nest materials! Let’s just say these feathered architects have an eye for luxury – soft mosses, downy feathers, and even the occasional shredded rabbit pelt. Nesting in style, one twig at a time.
How many eggs are typically in a clutch?
Great horned owls typically lay 1 to 4 eggs per clutch. The number can vary, but 2 eggs are most common. They incubate for about 30-37 days, with both parents involved in caring for the young.
What is the incubation period for eggs?
Great horned owl eggs hatch in about 30-37 days of incubation. You’ll likely see the female, patiently incubating them, while the male will go off to hunt frequently. This period calls for patience and protection so that the chicks may arrive safely.
Conclusion
This is quite contrary to what one might expect from a formidable predator, but great horned owl nesting exemplifies the best of flexibility.
You have learned about the varied locations they nest in, the remarkable appropriation of nests other birds are using, cavity nesting in trees, and even unusual sites.
More recently, their adaptability in urban settings confirms their strength and multicalendrical talents. This has enhanced your appreciation of the great horned owl’s nesting behavior by bringing to light the strategies for survival and success in diverse habitats.
