Califonia Bountiful

Spotted Owls

May/June 2005 California Country magazine

Wildlife biologist Lowell Diller has a very interesting talent--he can call out to spotted owls in the woods and they answer the call.

Myths, legends and how they're doing today


Wildlife biologist Lowell Diller has a very interesting talent--he can call out to spotted owls in the woods and they answer the call. More often than not the owls come to him, not close at first, but close enough to check him out.

Diller says calling owls is a matter of pitch and patience. The skill is easily learned with some practice. He shrugs diplomatically and doesn't comment when asked if he practices his calls in the shower.

He points out that for $13 anyone can buy a wooden owl caller, with a hoot enhancer, from a manufacturer specializing in game-calling instruments--turkeys, ducks and geese. The success a caller might have, however, probably won't equal Diller's.

He is a senior biologist for the Green Diamond forest products company in Humboldt County. He also is an adjunct professor in the Department of Wildlife at Humboldt State University.

Diller has studied the spotted owl in the forest for more than 20 years. He knows where they nest and when their chicks are born, what they eat and where they go. He is a leading authority on the species.

Diller took California Country magazine to Green Diamond's forestland near the Klamath-Trinity rivers watershed for a face-to-face encounter with these fabled creatures.

On cue a pair of owls swooped through the trees, perching in clear view, but still a safe distance away. After a live mouse was placed on the end of an extended stick, the big male owl swept from the trees, hovered for an instant within arms length, grabbed the mouse and flew back to the safety of a nearby branch.

The spotted owl, a species that has served as a rallying point for environmentalists who want to prevent logging and active forest management, has been credited with bringing timber harvesting on California forests--and those throughout the Pacific Northwest--nearly to a halt.

Along the way the spotted owl also has been the subject of much scientific research, including millions of dollars spent for studies that looked at such things as species demographics, genetics research, competition from other species, habitat condition and the adequacy of existing government regulations.

Through the years, many myths and legends have developed about these creatures, not all of them true or accurate. For example, there's the inaccurate myth that spotted owls can only survive in old-growth forests or that they are so scarce that humans rarely see them.

And, many have wondered, 15 years after it was listed as 'threatened' on the federal Endangered Species List, what's really going on with the spotted owl?

The Western Council of Industrial Workers, which represents workers in all aspects of the forest products business, took the U.S. Fish and Wildlife Service to court in 2002 to force the government to conduct the mandatory 'five-year' review of the Northern spotted owl's status as required in the federal Endangered Species Act. When the results of the review were made public several months ago, the researchers determined that the spotted owl is not 'endangered,' not in California and not even in the northern part of the bird's range where scientists said demographic results were least promising.

The U.S. FWS review recommends continued listing of the Northern spotted owl as a threatened species, but does not specifically recommend the same for the California spotted owl.

California Department of Fish and Game records indicate that about 2,300 California spotted owl sites have been located within the state, which translates to between 3,500 and 5,000 individual owls, but as much as 50 percent of the potential spotted owl habitat hasn't even been surveyed yet.

State wildlife experts say the location of these large populations of California spotted owls indicate a high degree of adaptability. Contrary to the common myth that the species can only survive in old-growth forests, California spotted owls live in a wide variety of habitats.

Experts say these habitats range from the Pit River in the north to the Southern California mountain ranges and cover a wide variety of climatic and ecological conditions. They're found in a variety of major forest types, including the Sierra Nevada mixed conifer, ponderosa pine, true fir, evergreen hardwoods and the oak woodland forest type.

The report noted that threats from logging, which has slowed to a trickle in the lush forests along the West Coast, has been replaced by the threat of forest fire as fuel loads have built to catastrophic levels.

And new threats are looming--the spread of West Nile virus, which can infect raptors, and the sudden oak death pathogen, which is killing native owl habitat. And then there's competition from invasive barred owls.

Diller said that although there are a number of environmental concerns for the California spotted owl, he sees the barred owl as a significant threat to spotted owl populations in Northern California and the Pacific Northwest. The barred owl, which historically has been found in the eastern United States, has been moving west and has an advantage over spotted owls because it's a bit larger and much more aggressive.

'It's kind of like the big, rude cousin who shows up at the family picnic and everybody else wants to leave because this person is so loud and obnoxious.' Diller said. 'It seems like that's how spotted owls view barred owls.'

The barred owl's northward and westward movement is a natural phenomenon, Diller said.

'You can't necessarily blame it on any human activities. Probably the only thing that we've done that contributes to this bird's westward expansion is plant trees around our towns and build parks, which probably has created stepping stones for the barred owl to migrate to other areas,' he said.

Diller said he thinks most biologists would agree that this was going to happen, just as it has happened with many other species through the millennia.

'With the retreat of the ice age, species that were separated have come back together,' Diller said. 'Sometimes one species displaces the other and sometime they don't.

'There's some hybridization of the two owl species going on and the best assessment of it right now is that we'll see one of two outcomes--either the two species will co-exist here in the West or we're going to end up with just barred owls.

'My guess is that the spotted owls will be completely displaced in British Columbia, Washington and parts of Oregon,' he said. 'I'm thinking this will take hundreds of years into the future to complete. In Southern Oregon spotted owls probably will co-exist with barred owls.

'But, barred owls don't appear to be doing as well as you go further south. It probably will be just spotted owls in the southern part of its range.'

'The U.S. Fish and Wildlife Service's scientific opinion that the California spotted owl seems to be surviving OK is now being taken to court by environmentalists,' said attorney Emma Suarez with the California Farm Bureau Federation Natural Resources and Environment Department.

Of importance to Farm Bureau members, she said, is the concern that scientific evidence indicates the California spotted owl is doing OK and the same conclusion has been arrived at over and over again.

'In as much as a court reaffirms the scientific methods used to arrive at that conclusion, then it's a good thing,' she said. 'But look, the service makes the scientific determination and that's not the end of it.

'Now environmentalists are suing over that determination. The end effect is that the service spends its resources going to court over a species that doesn't appear to need any help-- and, does so at the expense of helping species that do.'

The U.S. Fish and Wildlife Service's 5-year review of the Northern Spotted Owl can be found on the Pacific Region's Web site at

(Kate Campbell is a reporter with the California Farm Bureau Federation. She may be contacted at (800) 698-FARM or by e-mail at

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