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Northern Spotted Owl Trip - June 2005


Several books have been written about the spotted owl saga. The best is "The Final Forest" by William Dietrich (available at

If you search on "Stahl" at the Amazon Final Forest link you'll get a basic outline of my role without having to read the whole book.

Dietrich doesn't, however, plumb the interesting science story . . . the Forest Service's first spotted owl protection plan, circa 1980, called for protecting 500 pairs of owls each with 1000 acres of old-growth forest, these habitat circles to be spaced in a grid-like pattern across the owl's range from the Canadian border to the Bay Area. The balance of the owl's habitat would be logged.

My inquiry started with this question: why 500 pairs? The Forest Service cited a "personal communication" with Dr. Michael Soule (the spiritual founder of Conservation Biology). I called Soule and asked if the FS had cited his views accurately. "No." Soule never said 500 pairs would prove sufficient to maintain the owl's viability. Instead, he told the FS that a colleague (Ian Franklin) had observed that 500 fruit flies randomly mating in a jar were sufficient numbers to avoid fixation of a bristle hair mutant through inbreeding. Soule told me that inbreeding depression was unlikely the most significant risk faced by the owl -- he suggested I find a population demographer. With some help from my dad, who put me in touch with population geneticist Jim Crow, I found one of Crow's former students, Russell Lande. Lande was amused by the question -- how much spotted owl habitat is necessary to maintain a viable population?

While eating a lobster dinner in Maine, where I had run Lande to earth, he sketched on a napkin his proposal for answering the question (his later articles on the subject won him a MacArthur "genius" award). Lande started with some mathematics developed by Richard Levins to assess the success of pest control in a farmer's fields. Consider a field with discrete pockets of pest infestation. Two processes are at work -- the farmer's efforts to eradicate the infestations and the pest's concurrent dispersal to create new infestations. Only if the rate of pest pocket eradication exceeds the rate of pest dispersal and recolonization will the farmer win the battle.

Lande turned Levins on its head. The spotted owl's range is the farmer's "field" and each of the 500 1000-acre habitat reserves is an "infestation" that suffers local extinction when one of the resident owls dies and enjoys recolonization when an unpaired dispersing owl (of the appropriate sex) finds the vacated reserve. Assume further that dispersing owls from the reserves search randomly (no reason to think otherwise) and plug in the owl's demographic data, i.e., adult and juvenile birth rates, death rates and dispersal distances. For the owl population to persist the rate of successful recolonization can be no less than the rate of local extinction. For the Forest Service's plan -- 500 reserves of 1000 acres -- the rate of recolonization was substantially less than the rate of extinction, based upon the demographic data then available (and that's still the case using current data). To attain equal rates, Lande showed that all of the owl's extant habitat had to be preserved (and even this amount might not prove sufficient). Lande's analysis also predicts an "extinction threshold" (proportion of owl habitat) below which the rate of population decline accelerates.

With Lande's analysis in hand, I devised a series of lawsuits that I and two lawyer colleagues at Sierra Club Legal Defense Fund executed (we won six major spotted owl lawsuits). Our campaign culminated with the 1994 adoption of the Northwest Forest Plan, which protects 8 million acres of old-growth forests (80% of the owl's remaining habitat, compared to 5% protected by the Forest Service's original owl plan). Thereafter, FSEEE offered me this job and a chance to move home to Eugene.

I know of no guided service to see spotted owls. I've seen only one myself. A spotted owl researcher, hearing that I'd never seen one, grabbed me by the arm and took me to the woods so that I would have empathy for my cause. I suspect the lack of such tours may be based on the owl's status as a threatened species. Commercial tours on federal land require a special use permit, which the federal agencies may be reluctant to grant if the tour might "harass" the owl.

However, I have a friend . . . he studies spotted owls. If you're ever in the Eugene area, let me know and I might be able to arrange a private sighting for your life list!


Andy Stahl
Executive Director of FSEEE
(Forest Service Employees for Environmental Ethics) (

[NOTE: I (Kendric Smith) did not know Andy until I had some questions about FSEEE, but it turns out I knew his Father. He and I were in a similar area of science.]


Adam Steinbuck
Mendocino Redwood Company, LLC
850 Kunzler Ranch Road
P. O. Box 996
Ukiah, CA 95482

(707) 463-5110 - Main Number
(707) 463-5530 - Fax

They are a very environmentally conscious organization.
Their web site is:
They said that visits would be handled on a case by case basis.

The biologist with whom I dealt was Sarah Billig. She is a very nice recent graduate. With 2 people, you can fit in her truck (sort of). With more people you would have to drive your car over rough roads. The birds that we saw were about 12 miles from Willits, 6 miles of which were on the highway, but the birds could be anywhere in their big forest.

Don't take pictures of owls with a flash. You get red eyes, and then you have to try to paint them.


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