Owl Invaders

Owl Invaders

From a news story by
CNN San Francisco Reporter Don Knapp

September 26, 2000

Owls

(NOTE: You may recall the battle to save a threatened species, the northern spotted owl, threatened by logging old growth forests in the Pacific Northwest. Now, it appears the owl is under attack again. This time [it’s] from another owl and invader from the north.)

Wildlife biologist Stan Sovern shows how he calls in northern spotted owls close enough to be counted. But more and more, Sovern says, it’s another owl that answer's Sovern's call.

Stan Sovern hears the call of an owl and says, "That's a Barred."

After a few more calls, a short hike, and a little patience, a large barred owl lands on a branch, within feet of our camera. Then [it] swoops down to take a mouse, biologist Sovern placed on the ground.

Barred owls migrated from the eastern United States and are turning up throughout the spotted owl's range in the Pacific Northwest.

What little scientists know of the barred owl invasion, they've learned incidentally from monitoring spotted owl populations. And it seems, when barred owls appear, spotted owls disappear.

Researchers have documented about 15 to 20 cases of hybrid owls’ offspring of a mixed marriage between spotteds and barreds. And [there’s] one case of a barred owl killing a spotted owl.

A decade ago, the federal government declared spotted owls a threatened species and dramatically reduced logging on seven million acres of public lands to protect spotted owl habitat.

Stan Sovern says, "This is one of those variables that sort of argues for being conservative when you start coming up with management plans. There's always unknown things with other species that we can't possibly predict."

It’s not yet clear what, if any, impact the arrival of the larger, more aggressive barred owls will have on logging restrictions designed to protect spotted owls.

Professor Ned K. Brown of the University of California-Berkeley says, "In some areas of Washington, the barred owls moved into very dense, deep woods. The same kind of woods that are opened up, or destroyed by logging, that adversely influences the spotted owls."

No one knows why barred owls are moving into spotted owl country, but scientists say it's not likely anything can stop them.

Further notes and discussion:

Barred owls are about 17 inches long and have a wingspan of almost four feet. These dark-eyed birds’ markings are a mixture of white, light buff, and brown. Diet includes mice, small mammals, insects, fish, and snakes. They normally hunt for food at dawn and dusk but will hunt on cloudy days. Barred owls have been known to eat other smaller owls.

Although the story deals with the migration of barred owls from the northeastern United States, barred owls live in other parts of the country and Canada. They are commonly found in Florida’s swamps and river bottoms. They like to build nests in the cavities of trees. Florida campers like to imitate the sound of the barred owl as it sometimes sounds like the bark of a dog.

Additional Notes: