By Mary K. Hanson
I was walking with my dog through a stretch of riparian — riverside — habitat in the region, and was suddenly attracted to the sound of a group of acorn woodpeckers, high up in the trees, having a squawking fit over something, so I went to see what the problem was.
At first, all I saw was the woodpeckers themselves. They were in quite a tizzy, shouting their loud, rasping calls as they jumped from branch to branch, flashing their wings. I couldn’t see anything in the tree that might have been the cause of such a ruckus, however, so I looked around a bit more. And then I spotted it.
In another tree just a few feet away was a huge great horned owl (bubo virginianus).
Basking in the early-morning sun, he swiveled his large head around, looked at me with sleepy, amber-gold eyes and then proceeded to completely ignore me. I couldn’t ignore him, though. In fact, I think I stood there for about 20 minutes or so just watching him and taking photographs. Great horned owls are one of the most easily recognizable owls in the country, but I’d never seen one this close up before. I was mesmerized.
Sometimes called “cat owls” because of their ear-like tufts, great horned owls occupy a wide variety of habitats in California, including riparian forests, cliffsides, deserts and even residential areas. And they’re not particular about where they nest, either. These owls may take over the treetop nests of other large birds, or move into an abandoned squirrel’s nest, occupy stumps, ledges, barns and “owl boxes” or other manmade structures.
Nesting season is generally between December and July — so we’re right in the middle of it now. Although they only use a nesting site once in a season and don’t return to it the next year, the owls are good tenants, with both parents looking after their young nestlings and one another. Female great horned owls usually lay two or three eggs in a clutch and then both parents take turns incubating them, with the male leaving the nest only to hunt down food for his mate.
Great horned owls have a somewhat broad diet that sometimes can include other birds (which explains why the acorn woodpeckers were so upset that the owl was so nearby) and prey larger than themselves, but they most often stick to mice, rabbits, squirrels and other small mammals, including skunks.
Like all owls, the great horned owls tend to swallow their meals whole, and then regurgitate up the indigestible parts like bones and fur in “pellet” form. (It’s not uncommon to find complete mouse skulls in these pellets.)
Once the owlets arrive, both parents remain to care for them until they’re about 9 weeks old and ready to fly off on their own. Even after the owlets are airborne, their parents still may look after them for a few more months. In fact, great horned owls are exceedingly protective of their young; they’d have no qualms about attacking a human who got to close to their youngsters. So, if you see a nest or owlets, it’s best to give them a wide berth.
Over the past few weeks, I’ve been able to spot several of these large, handsome birds in the local area — including a female in her nest above an outcropping of mistletoe — so keep an eye out for them, especially if you’re walking just before dusk when they’re heading out to hunt or just after dawn when they’re heading back to their daytime resting sites. And remember to take lots of photos!
— Tuleyome Tales is a monthly publication of Tuleyome, a conservation organization with offices in Woodland and Napa. Mary K. Hanson is an amateur naturalist and photographer who is the author of “The Chubby Woman’s Walkabout” blog. For more information about Tuleyome, go to www.tuleyome.org.