Sunday, November 18, 2007

The birds are back - along the Pacific Coast Flyway


..."In the late 1970s and 1980s, we were witnessing steep declines in birds, and it was very frightening," Chisholm said. "But the habitat restoration programs we've seen in the past 20 years have made a tremendous difference. It's not just the number of programs - it's the scale."

Right now, said Chisholm, Audubon California is participating in a project near Colusa in the Sacramento Valley that will turn 7,000 to 9,000 acres of former rice land into floodplain wetland.

"At Owens Lake, 50,000 acre feet of water that used to go to Los Angeles each year is now restoring the lake, creating fantastic shorebird habitat," Chisholm said. "Huge restoration projects are coming together at Tule Lake and Goose Lake in northeastern California, the Tulare Basin in the southern San Joaquin Valley, even the Colorado River Delta in southern California and Mexico. To a very significant degree, we're changing the face of the landscape in a way that benefits wildlife."

Chisholm also credits the decomposition rice program - which involves flooding fields in winter to decompose rice stubble instead of burning it - with a major role in improving flyway conditions.

"That change came out of clean air regulations, because burning rice straw was a serious air quality problem for the Sacramento Valley," Chisholm said. "But the program also has been a tremendous boon for waterfowl, shorebirds and wading birds. It has essentially created hundreds of thousands of acres of seasonal wetlands where birds can feed and rest through the winter and early spring."

...The new habitats have not only made birds more numerous - but they've also made them healthier. Throughout much of the late 20th century, wintering Central Valley waterfowl periodically suffered massive die-offs from botulism and avian cholera - the result of too many birds squeezing into too few places, contaminating their resting and feeding areas with fecal waste.

"There were times when we lost tens of thousands of ducks," recalls Greg Mensik, the deputy refuge manager of the Sacramento Valley National Refuge Complex. "I remember one day before the opening day of duck season when I picked up 125 carcasses. It was extremely depressing."

Today, said Mensik, such plagues are a memory....

"It's been at least 10 years since we've had a major incident," he said. "In large part, that's due to both the enhanced public and private marshlands and the expanded decomposition rice program. We've gone from 60,000 to 70,000 acres of flooded rice to 200,000 to 300,000 acres. The birds aren't packed together anymore, and it's harder for disease to spread."...

"Around 1980, we had a valley-wide population of about 125 ibis," Mensik said. "Today, there are between 50,000 to 100,000. No one really expected it."

To keep the birds burgeoning on the Pacific Flyway, the money will have to keep flowing - not just for restorations, but to manage the wetlands that have been restored. To stay productive, wetlands must be meticulously maintained, say wildlife managers.

"If you establish a wetland and then walk away, you'll see successional ecological changes over time that will eventually turn it into grassland and forest," said Dan Yparraguirre, a waterfowl coordinator for the California Department of Fish and Game. "We need to manage our wetlands for the species we want to benefit. That can involve any number of practices - land leveling or dredging, planting or removing vegetation, adjusting water levels. It's an active, ongoing process."

So despite the good news, the Flyway's birds are by no means home free. The pressures that winnowed their numbers in the 1980s - urban development and conversion of habitat to intensive agriculture - remain. Chemical contamination and oil pollution at critical habitats remain a chronic problem, as evidenced by the recent spill of 58,000 gallons of bunker oil in San Francisco Bay from a container ship that bumped a piling on the Bay Bridge. The bay and the contiguous Sacramento-San Joaquin River Delta comprise some of the most important wintering, staging and breeding grounds on the Flyway. And while the impact of new threats - most notably global warming and climate change - have yet to be fully felt, they are likely to be profound.

That said, the fact that we still have multitudes of birds that can darken the skies, the fact that we have rebuilt their numbers against all odds, the fact that they remain with us - well, some celebration is in order...

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