Whooo are you? There's an owl in your neighborhood

Picture this: You're hiking through a forest just as the sun slips down behind the trees. Songbirds and squirrels have fallen silent, bedding down for the night. Bats have not yet emerged. All is still except for the crunch of your boots on the dirt path. Suddenly, something above you calls out.

Hoo! Hoo-oo-oo-oo! Hoo! Hoo!

You look up just in time to see a feathered figure glide from one tree to another, its six-foot wings spread wide. Perching on a branch, the bird blends with the tree trunk, almost disappearing from view.

You have just seen an owl – a sight that owlers enjoy.

Children's writer Jane Yolen introduced readers to the nocturnal activity of "owling" with her beloved picture book "Owl Moon."

In it, a girl and her father take a nighttime walk through a New England forest near their farm. "Pa" imitates the call of a great-horned owl, and the enormous bird hoots back. Then it appears. The girl is awestruck.

Is such a thing possible? Can you really call owls to you?

Yes, says Steve Gordon, who leads expeditions for the Lane County Audubon Society in Oregon. He explains that if you can imitate an owl's cry, even roughly, it will answer. "When you hear the call, just call back," he says.

Before you embark on your quest to see who gives a hoot, you'll need a few items.

First, make sure you bring a grown-up. And wear sturdy, closed-toed shoes or boots. You'll be walking on unfamiliar ground in the dark. Second, bring a working flashlight or headlamp. Finally, you might want to bring along a small, lightweight tape recorder. Then you can record and play back the sounds of the owls you discover!

Many owls are nocturnal. This means they're active from dusk until dawn. While you're winding down from your day, some owls are just waking up and leaving their nests to talk with one another. This is the best time to spot them in the wild. Later on, they're busy hunting – an activity that demands absolute concentration – and silence.

"You can also go out before dawn," says Mr. Gordon. "Nocturnal owls are often active in the last couple of hours before [daylight]."

Maybe you live in the country, with acres of forest around you. Or possibly you live in a suburban area with just a few trees in your backyard. Either way, you probably have owls for neighbors.

Screech owls and barn owls are cavity nesters; they view a hole in a tree as Home, Sweet Home. Larger birds, such as great horned owls, take over abandoned crow and hawk nests in tall trees.

All owls leave hints as to their location. It's up to you to look for the clues! Often, you'll spot whitish streaks on a tree trunk or on the ground beneath a high limb. These streaks are "mutes" (or bird poop), left by an owl that regards the tree as his favorite hangout.

Owls also make pellets. Anyone who's read Jane Hammerslough's kids' science book, "Owl Puke," knows that owls usually swallow their food whole.

However, they can't digest certain parts of mammals and small birds. Their stomach creates a pellet with the sharp bones of the prey on the inside and the soft fur or feathers on the outside. Soon after eating, owls cough up a pellet, which ends up on the ground. Owl pellets are about 1-1/2 inches long and grayish-white or black. If you find one, you'll know that an owl is near. (See sidebar on next page to learn how to dissect an owl pellet.)

'Tigers' in the trees

Ready to go owling? Several species of owls easily adapt to rural or suburban environments.

The first is the great horned owl. These birds are sometimes called "tigers with wings" because they're fierce hunters. They weigh between three and five pounds and stand about two feet tall, with two distinctive feathered "horns" on top of their heads.

Great horned owls may eat as many as 4,000 mice a year, and they'll chow down on squirrels, voles, frogs, skunks, and almost anything else their talons can seize!

These owls are found throughout North America – in remote wilderness, populated countrysides, and even in cities. At dusk, they cry a series of four to seven low hoots.

When you hear an owl hooting, hoot back. Stay under a tree and avoid open fields. You want to be able to see the owl before it sees you and flies away. Try not to use your flashlight too often. Let your eyes get used to the darkness and see if you can entice an owl to land near you. Owls are curious creatures; if they hear a hoot, they want to know who's talking!

A pleasant 'screeching'

Eastern and western screech owls prefer to live in forests, but they'll happily make a home in a woodpecker hole or a nest box you've put up in your backyard. These owls – weighing less than a pound and standing only eight or nine inches tall – hunt small rodents and insects, as well as salamanders, crayfish, and snails.

The screech owl's name is deceptive. Rather than a screech, this bird's song sounds like a bouncing ping-pong ball. The call lasts about three seconds and sometimes contains as many as 35 notes.

Brent Harrison, who directs kids' sports camps at the University of Oregon, looked up one night in his suburban backyard and saw two screech owls looking back at him. "It sent shivers down my spine," he says.

While screech owls have a pleasant voice, barn owls are the real screamers. These white and brown birds, a foot tall with an almost four-foot wingspan, are found almost everywhere in the world. They're distinctive because of the heart-shaped feathered disc around their faces and for their ear-piercing shrieks.

Barn owls eat 1-1/2 times their own weight every day. Like other raptors – that is, birds of prey – barn owls are extremely helpful. Without them, our houses, barns, and yards would be overrun with rodents.

You'll know a barn owl the minute you see it gliding across a field in search of dinner. Its white wings almost glow in the dark, and its scream is unforgettable.

You can attract these beautiful birds by building and putting up a nest box. Often, a pair of barn owls will take up residency and become your neighbors for years!

Did you know that there are hundreds of species of owls? Different types live in different parts of the world. The smallest, called an elf owl, lives in saguaro cacti in the southwestern United States. One of the largest, a snowy owl, loves the cold plains of northern Canada.

Some owls are easier to spot than others, says Mr. Gordon. "Some are diurnal," he explains, "which means they're awake during the day." Snowy owls, burrowing owls, and pygmy owls perch in broad daylight.

Once, he had the opportunity to help a baby owl. "I found it on the road," he says, "and I didn't want a car to hit it, so I got a dishrag and a box and put the owl back in the crotch of a tree. I looked up and its parent was on a low branch nearby. The owl was a baby, just learning to fly."

Mr. Gordon did the right thing. Baby owls on the ground are usually uninjured – they're just fledglings learning to take to the air while their parents watch. However, if you find what you believe to be an injured owl, don't pick it up. Gently place a box or a blanket over it and call your local wildlife rehabilitation center. Trained volunteers will be happy to help.

The famous nature writer Henry David Thoreau once wrote, "I rejoice that there are owls." The night you discover your first owl in the wild, you'll rejoice, too!

Those interested in owls will enjoy a look at a raptor center at which Ms. Hart volunteers (see story).