UPS AND DOWNS.

Byline: Susan Palmer The Register-Guard

CORRECTION (ran 8/10/2005): A story on Page D1 in Tuesday's Register-Guard about bird banding in the Willamette National Forest misspelled the name of forest spokeswoman Patti Rodgers.

IKENIK STATION - The orange-crowned warbler tangled in a mist net blinked and trembled once as biologist Tim Pitz carefully pulled the net strands away from its body before tucking the bird into a small cotton sack on his belt.

This little guy's a great flyer, said Pitz. Just over 4 inches from head to tail, the orange-crowned warbler breeds in North America each summer before flying up to 4,000 miles to winter in the tropics.

But the nondescript creature with a touch of orange on its head and a yellow-tinged breast is in decline in the Willamette National Forest, one of four neotropical species that research suggests are decreasing throughout the Pacific Northwest.

The news isn't all bad. The research shows six other neotropicals - small songbirds that breed in North America each summer but winter south of the equator - are increasing.

The research being done by Pitz and hundreds of others across the country may help Forest Service officials develop management plans beneficial to the birds.

Ikenik Station, a boggy meadow criss-crossed by narrow creeks and seeps a few miles west of Clear Lake off Highway 126, is one of six study sites in the Willamette National Forest. It's part of the avian productivity and survivorship survey conducted by the Institute for Bird Populations based in Point Reyes, Calif. The research, begun in 1989, includes hundreds of North American monitoring sites.

Locally, two interns have visited each of the six sites in the Willamette every 10 days since May. On Friday, with help from their supervisor Pitz, Camila Gomez of Colombia and Mark Arnold of Pennsylvania raised the almost invisible nets just after dawn and checked them every 40 minutes for the next six hours, examining and banding trapped birds before releasing them.

On average, said Pitz, 20 to 30 birds will fly into the nets on a given day, but the number varies widely. At a Washington state site, the nets once captured 200 birds in a single day.

"It's pretty variable from year to year," he said.

The birds' size, gender, age and overall health are noted, and a tiny metal band with a unique number is attached to each bird's leg. The bird is weighed and then allowed to fly free in a process that takes a few minutes.

But Pitz and his interns don't limit their observations to the birds they catch.

They also record species they see and hear as they work. Since the observation station was set up in 1992 at Ikenik, researchers have seen 85 different species there. Some are transient visitors such as the American green-winged teal, the lazuli bunting and the belted kingfisher.

Others are regulars who breed and raise their young there, such as the MacGillivray's warbler, another species that has declined recently in the Pacific Northwest.

With years of data on the birds, the habitats and even the weather, Institute for Bird Populations researchers are producing reports that can help federal officials determine the impacts of their land management decisions. Most recently, the institute provided the U.S. Forest Service with a report detailing land management strategies that would support bird habitat in the Pacific Northwest.

The institute also expects to see how changes in land management influence species, and to compile enough data to begin predicting outcomes of management decisions, said Philip Nott, an institute biologist.

Nott, who has written extensively about bird populations, believes that 50 to 90 percent of the reproductive success of birds can be attributed to the changes in seasonal weather driven by ocean warming and cooling trends known as El Nino in the Pacific Ocean and the North Atlantic Oscillation in the Atlantic.

If birds face a drier winter in the tropics, said Pitz, they may have fewer insects to eat. That means fewer birds returning to breed in North America and less healthy birds that produce fewer offspring.

Loss of habitat or an increase in predators can also quickly take their toll on birds, he said.

Birds, Pitz said, are "good indicators of ecosystem health, and they're fairly easy to monitor compared to other species."

The research of Pitz and his interns will be considered as foresters revise the management plan for the Willamette National Forest, said Patty Rogers, a spokeswoman for the Eugene-based forest.

The plan revision won't begin until 2009, but current annual species monitoring will be evaluated, she said. It's not just the about the birds, however.

"We cover everything: air, water, wildlife, fisheries, botany. We also examine the socioeconomic aspects of the forests," she said. "The monitoring that we have done every year is helping us to refine and learn exactly what we will need to take into the next plan revision."

FOR THE BIRDS

Doing well: Neotropical birds in the Willamette National Forest whose numbers have increased in recent years: Hammond's flycatcher, warbling vireo, Swainson's thrush, Wilson's warbler, common yellowthroat and Lincoln's sparrow

Struggling: Neotropicals whose numbers have declined in recent years: Western flycatcher, dusky flycatcher, orange-crowned warbler and MacGillivray's warbler.

Learn more about this research at the Institute for Bird Populations at www.birdpop.org

At the meadow: For a list of species seen at the Ikenik Station since 1992: www.birdpop.org/nbii/status/statusresults.asp ?strStation=11157

Closeup view: For photos and thumbnail descriptions of birds and their habitats: www.mbr-pwrc.usgs.gov/id/framlst/infocenter.html.

CAPTION(S):

The research being done by Tim Pitz and others across the nation may help Forest Service officials develop management plans beneficial to the migrating birds. Chris Pietsch / The Register-Guard Biologist Tim Pitz examines a MacGillivray's warbler after extracting it from a mist net in the Willamette National Forest. Pitz and a team of workers are banding and identifying birds as part of an international bird migration research project. Tim Pitz examines an orange-crowned warbler as part of his work in the Willamette National Forest to identify and monitor birds, which are good indicators of ecosystem health. Chris Pietsch / The Register-Guard