Great Horned Owl, Bubo virginianus
DIET: Rodents and other small animals, including skunks.
PREDATORS: None.
HABITAT/RANGE: Much of North America. Adaptable to places with trees in general, but in SB, especially common to see in eucalyptus groves.
CONSERVATION STATUS: Least concern.
WHERE TO OBSERVE IN SB:
It's easy to recognize a great horned owl when you see one. These birds have distinctive tufts of feathers on their heads that resemble horns or cat ears. They feed on rodents and other small mammals and can be found in trees at the edges of clearings.
Appearance
Great horned owls are large raptors with neutral colored feathers and large forward-facing eyes. Like most owl species, the females are larger than the males, but otherwise resemble each other. The owls' horn-like tufts, from which they get their name, easily differentiate them from barn owls and other raptors in the area. Although some people may think these tufts are ears, they are actually just feathers used for territorial displays. The birds' actual ears are small openings underneath their feathers.
Great horned owls tend to sit very still in trees and camouflage well, so you're more likely to find an owl by hearing it than by seeing it.
Calls of the Great Horned Owl
The stereotypical hooting call associated with owls is one of the most common sounds of the Great Horned Owl, although not the only sound they make. In some cases, a screeching call may be heard, such as from juveniles begging for food, or from adults defending their nest. Listen to the varied calls of the Great Horned Owl on the Cornell Lab of Ornithology's website, or watch the video on the left to hear the call of a juvenile owl in La Mesa Park.
Ecological Roles
Great horned owls feed mostly on small animals, including lizards, birds, fish, and especially rodents. They also are the only natural predators of the striped skunk, since they are immune to the smell and effects of its musk, and in some cases they even prey on smaller owl species. It's common for a great horned owl to perch in a tree overlooking an open area, because it can easily hunt rodents from there. The specialized wing feathers of great horned owls allow them to fly with almost no sound, so as to not alert prey of their presence.
Your Natural Rodent Control
In areas close to human habitation, owls and other raptors play an important role in regulating populations of rodents such as roof rats, mice, and gophers. You can protect them, and other predators (even domestic cats and dogs) by avoiding the use of rodent poison. Certain kinds of anticoagulant rodenticides can cause secondary poisoning, meaning that the predator becomes poisoned itself after eating a poisoned rodent. This causes a painful death for the predator, and is also counterproductive in the control of rodents. Excluding rodents from your home and other unwanted locations with barriers, and using traps when necessary, allows you to keep the rodent population from getting out of hand without harming their natural predators.
Behavior
Great horned owls are nocturnal. They commonly start hunting at dusk, and stay out all night. Typically, an owl will start off by perching in a tree or other tall object at the edge of a clearing, scanning the ground for prey. Although they cannot move their eyes, great horned owls can rotate their heads almost all the way around to watch for movement. When an owl sees prey, it will fly silently down and attempt to grab the animal with its talons. Owls swallow their food whole, and regurgitate the bones and other inedible parts as pellets.
Great horned owls usually mate for life, and it is not uncommon for them to keep the same territory for the rest of their lives. Mother owls typically stay with their young several months after fledging to teach them the skills they need to survive.
How to Observe Great Horned Owls
In Santa Barbara, owls (and other raptors) are often seen perching in eucalyptus trees, since these tend to provide open branches with good views. The eucalyptus groves at La Mesa Park and Arroyo Burro Open Space have both been known to host great horned owls.
In the daytime, owl droppings, pellets, and feathers are good indicators that an owl frequents an area. Owl droppings appear as a whitewash-like substance on the trunks of trees that owls commonly perch in. Pellets, the masses of animal bones and other un-digestible parts that owls cough up, resemble animal scat and are found underneath trees. Sometimes, you can identify a raptor feather as being from a great horned owl if it smells skunky, because great horned owls are the only raptors that prey on skunks (being unaffected by their musk).
Once you have identified a place frequented by owls, go there around sunset and wait quietly for the owls to come out. Great horned owls are often heard before they are seen. Listen for their calls, and look for the silhouette of an owl perched in a tree or flying above a clearing. Imitating the call of the great horned owl will sometimes attract an answer, enabling you to more easily locate the bird.