Great horned owls are nocturnal birds of prey that are known for their loud, hooting calls that can often be heard at night. These large owls have prominent ear tufts, or “horns”, on their heads that give them their common name. Great horned owls are found throughout North and South America and can thrive in a variety of habitats from forests to deserts to urban areas. But why do these owls make such a racket at night? The main reasons great horned owls vocalize after dark are to communicate with mates and offspring, establish territories, and warn off potential intruders.
To Communicate with Mates and Offspring
One of the primary reasons great horned owls call at night is to communicate with their mates and offspring. Great horned owls tend to form monogamous pair bonds that can last for multiple breeding seasons. The male and female rely on calling back and forth to maintain contact, coordinate hunting and nesting activities, and defend their territory. Great horned owl calls can carry for miles and allow the birds to locate one another even when separated by long distances.
Great horned owl pairs also use vocalizations to communicate with their young once the eggs hatch and nestlings emerge. The parents may call to the owlets to indicate that food has arrived after a hunting trip. The owlets beg and screech loudly when hungry, prompting the adult owls to respond with food items. This back-and-forth vocal communication allows great horned owl families to effectively provision and raise offspring until they fledge from the nest.
Types of Communication Calls
There are several distinct types of vocalizations used by great horned owls when communicating:
- Territorial calls – Deep, resonant hoots used to establish territories and ward off intruders.
- Contact calls – Softer hoots and calls used between mated pairs to maintain contact.
- Begging calls – High-pitched screeches and hisses emitted by owlets when hungry.
- Alarm calls – Harsh barks or screeches in response to danger or threats.
By calling out in the darkness, great horned owls are essentially having complex vocal conversations essential to their breeding and survival.
To Establish Territories
Another reason great horned owls hoot at night is to establish and defend their nesting territories. Great horned owls are highly territorial, with each monogamous pair staking claim to an area of woods or habitat to nest and hunt in. The male owl takes the lead in calling out with low, resonant hoots that can echo over a distance of several miles. These territorial calls serve to warn other great horned owls away and announce that an area is occupied by a breeding pair.
Great horned owls will defend their territories aggressively against perceived intruders. They have even been known to fight to the death when territorial disputes escalate. Therefore, the male’s nightly hooting plays an important role in delineating boundaries and trying to avoid dangerous territorial combat whenever possible. Any encroaching male great horned owls will hear the hooting and likely retreat to avoid an attack. This helps maintain stable breeding territories across the species’ range.
When Are They Most Vocal?
Great horned owl vocalizations peak during the late winter and early spring as they prepare to nest. The hooting reaches a crescendo during January and February during the height of mating season. It tapers off slightly but remains frequent through March and April as incubation gets underway. Territorial calls pick back up in late summer and fall as fledglings leave nests and juveniles disperse to establish their own territories. The intense hooting announces that nesting spots are taken and warns young owls to move on.
To Warn Off Intruders and Predators
Great horned owls also hoot at night to mob potential intruders and warn them away from their territories. Their calls carry an aggressive tone that tells predators like foxes, coyotes, or other owls to steer clear. The hooting can even be specifically directed at certain intruders that the owl can see or hear nearby. This mobbing behavior is a defensive tactic meant to scare off threats without the owl having to attack. It serves as a warning that the owl is big, strong, and prepared to defend itself if necessary.
In addition to warning off predators, the calls may also communicate to potential prey animals like rabbits, hares, or rodents that a dangerous predator is in the area. This can cause the prey to freeze in place or retreat to safety, making them easier for the owl to ambush. So the nighttime hooting has hidden advantages that aid the owl’s hunting abilities as well.
Adaptations for Nocturnal Calling
Great horned owls possess several special adaptations that allow them to effectively call and communicate at night:
- Large Eyes – Their extra-large eyes with pupils that open widely in darkness enhance their vision at night.
- Facial Discs – These concave, dish-shaped facial feathers help direct faint sounds towards their ears.
- Asymmetrical Ears – One ear is higher than the other, improving their ability to pinpoint sound sources.
- Powerful Chest Muscles – Allow great horned owls to project their low, booming hoots over long distances.
- Keen Hearing – Their sensitive ears can detect even faint noises in the darkness.
Thanks to these special adaptations, great horned owls are equipped for optimal nocturnal communication and hunting. Their nightly choruses are part of a complex social interaction system that these birds rely on for breeding and survival.
Conclusion
Great horned owls are famous for their vocal prowess and their loud calls can become a regular part of the nighttime soundscape in areas where they reside. While their noisy hooting may wake some people or even strike fear in the hearts of small prey animals, it is not done out of malice. The owls are simply following instincts honed over eons to communicate with mates and offspring, ward off intruders, and effectively hunt under the cloak of darkness. Understanding why great horned owls call at night provides insight into their family bonds, territorial behavior, and survival strategies. So the next time you hear the booming hoots of a great horned owl in the night, take a moment to appreciate the complex social interactions and adaptations at work behind their impressive vocal displays.