New threats imperil spotted owl

Article Date: 2004-06-22   Source: http://www.tdn.com   Comments: 0

Portland, Oregon, U.S.A. - Protecting old growth forest habitat for the northern spotted owl is more important than ever because the bird faces new threats from its cousin the barred owl, West Nile virus, and sudden oak death, a panel of scientists said Monday.

''Habitat is critical,'' said Jerry Franklin, a University of Washington professor of forest ecology.'' Given all the uncertainties on the risk to spotted owls, it would just be exacerbated by the removal of additional habitat.''

Though the northern spotted owl is one of the most-studied birds on Earth, the magnitude of the new threats is not well understood due to gaps in research, said John Marzluff, professor of wildlife science at the University of Washington.

"The spotted owl really taught us a lot about conservation in the last decade in terms of (habitat) reserve design," said Marzluff. "Now it's going to teach us what kind of sacrifices we have to make to battle some of these new threats."

Franklin and Marzluff are among nine scientists who have spent the past 6 months reviewing more than 1,000 research papers and interviewing northern spotted owl experts for the U.S. Fish and Wildlife Service, which is under court order to complete a review of the bird's threatened species status by Nov. 15.

The scientists were to outline their findings at their last public meeting Tuesday in Vancouver, Wash., before assembling their report, which will take two or three more weeks, said Steven P. Courtney, vice president of Sustainable Ecosystems Institute, which assembled the scientists and is overseeing the information gathering phase of the review.

The status review of the spotted owl and another of the marbled murrelet came out of the Bush administration's settlement of a lawsuit brought by the timber industry, which wants to ease logging restrictions that protect the birds' habitat in Northwest national forests. The reviews marked the first time a private contractor was hired to assemble the information.

"We emphatically will not be making recommendations on anything to do with the listing under (the Endangered Species Act)," Courtney said. "Essentially we will be coming up with a statement on where the populations are and what the science says at this point. We won't be making any recommendations on management."

When the spotted owl was declared a threatened species in 1990, the greatest threat to its survival was the loss of its old growth forest habitat to logging, the scientists said.

Owl populations are still declining, but the Northwest Forest Plan, instituted in 1994, has conserved habitat on federal lands in western Washington, Oregon and Northern California, the scientists said.

Maturing forests that were cut or burned in the 19th Century are developing as new habitat, but wildfires, particularly east of the Cascade range, pose an increasing threat for destroying large tracts of owl habitat, the scientists said.

Now the spotted owl faces threats from the barred owl, which is pushing the spotted owl out of its territory since migrating from Eastern Canada in the past century; West Nile virus, a mosquito-born disease fatal to humans as well as spotted owls, and sudden oak death, a pathogen spreading through California into southern Oregon that kills trees the owl depends on.

"When it was just barred owls, I was not so concerned," said Alan Franklin, a research scientist from Colorado State University. "Then you get sudden oak death and West Nile virus. You're getting three factors that are going to hit them on some level we don't know. The whole multiple stressor thing has me very concerned about what is going to happen."

The threats do not appear dire at the moment, Gutierrez said. Owl populations are stable in some areas. And they are spread over a large range.

The barred owl may be the worst of the new threats, particularly in Washington, but the only way to test that idea would be to kill barred owls and see whether spotted owls move back, said Rocky Gutierrez, a professor of wildlife biology at the University of Minnesota.

Dealing with the new threats will be much more difficult than habitat loss, because there are no clear remedies, the scientists said. West Nile virus has not reached Oregon, but there is no cure for it. Because of their small population, spotted owls have less chance than common birds like crows of developing immunity. Sudden oak death kills tanoak, an important component of habitat for the spotted owl and its prey in southern Oregon and Northern California.

Related Articles:
2009-12-09 - Barred owls could get the boot (or a bullet) to save spotted owls by Matthew Preusch - Portland, Oregon, U.S.A.
2008-06-03 - New Threats to the Spotted Owl Prompt Legal Notice on the Elliott State Forest by Noah Greenwald - Portland, Oregon, U.S.A.
2007-06-12 - Spotted Owl Old Growth Habitat Protections Reduced - Portland, Oregon, U.S.A.
2007-04-28 - U.S. proposes killing owls to save another - Portland, Oregon, U.S.A.
2007-03-16 - Spotted owl ruling halts local logging by Paul Fattig - Portland, Oregon, U.S.A.
2007-02-16 - Appeals court says spotted owl protection violated by William McCall - Portland, Oregon, U.S.A.
2005-04-20 - Old Growth Up, Spotted Owl Numbers Down by Jeff Barnard - Portland, Oregon, U.S.A.
2004-06-01 - Experts ponder latest menace to the spotted owl - Portland, Oregon, U.S.A.

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