Steadying her mini-telescope in the mud, Muriel Kotin cooed as she spied on a fist-sized bird with yellow tips under its wings, perched in an olive tree.
"For those of you who don't know, that's a yellow-rumped warbler," Kris Ohlenkamp told the 31 bird-watchers on a recent Sunday morning.
The little bird flitted away with three staccato tweets, and a stately red-shouldered hawk swooped down to roost in the tree's top branch. The soft early rays of sunlight glinted off the hawk's orange eyes as it swiveled its head almost completely around and confidently surveyed its territory. A familiar crowing disrupted the peace.
"That's a chicken!" Kotin said.
"Yes, there's a rooster over there," Ohlenkamp said, pointing to the high fence of the Donald C. Tillman Water Reclamation Plant.
Just then, a motorized model airplane swooped over the fence and crashed into pieces. Two teen-agers rushed to the fence. The hawk flew away.
With the model airplane, the sounds of civilization--the droning of traffic, the huffing of joggers--came rushing back in. These bird-watchers had to go no farther than the heart of the San Fernando Valley--in the Sepulveda flood control basin--for some first-class "birding."
In fact, the wide-open fields in the basin at the northwest corner of one of the world's busiest freeway intersections--the San Diego and Ventura freeways--is also one of the country's busiest crossroads for migratory birds.
"They stop in from all over; we've counted 180 species," said Ohlenkamp, 42, a San Fernando Valley Audubon Society member who's been giving tours here for 15 years. "Any bird passing through here will stop in this large patch of green in the center of the Valley." (The most prolific birding areas in the country are waterfront places such as Freeport, Tex., and Morro Bay in San Luis Obispo County, where species counts exceed 200.)
Ohlenkamp's eyes turned toward an unusual whistle, and he scratched his head as he spotted a female Northern oriole.
"She's supposed to be in Central America right now," he said.
Birds dropping by enjoy a habitat that is relatively free of predators. Coyotes stick to the hills; few foxes make it over the freeway, and hunting is prohibited.
The basin, also known as the Sepulveda Dam Recreation Area, is owned and operated by the U. S. Army Corps of Engineers and leased to the city of Los Angeles. It is a dry reservoir area serving the 52-year-old Sepulveda Dam and is designed to catch runoff from the surrounding mountains. That's why the area flooded so drastically in last spring's storms, and that's why no buildings are allowed in the wildlife refuge area, which is in the southeast corner of the basin.
Two years ago, a coalition of local environmentalists formed the Wildlife Areas Steering Committee, which is working toward expanding the protected status of the flood-control area to make it a world-class urban bird sanctuary.
"To become world class, we need to have the area re-vegetated with natural plants, no introduced species, and we need to have more area designated as a wildlife refuge," Ohlenkamp said.
To do that, the birds need water. The two lakes in the 60-acre wildlife area are composed of treated waste water pumped out sporadically by the treatment plant, but the differing water levels disturb the birds, Ohlenkamp said.
Environmentalists recently won permission from the Southern California Regional Water Quality Control Board to have a steady and unvarying flow of water into the area.
In two years, the nearby Valley Sod Farms will be dug up by the treatment plant, and then the wilderness district is scheduled to expand from 108 to 140 acres--with minimal recreational use.
"We are studying what effects certain recreation has on the birds and their nesting habits, and we're coming up with a master plan," Ohlenkamp said. So far, the model airplane field doesn't seem to scare off the birds.
Ohlenkamp, an industrial hygienist, is one of 2,800 members in the Valley Audubon chapter. The birders are of all ages and ethnic backgrounds, said this year's local president, Arthur Langton, a junior high school science teacher.
"People are attracted to this because it's a test of skill and observation," said Langton, who recently led a Christmas bird count to seven areas in the Valley, including Encino Reservoir, Hansen Dam and Pierce College.
"Even if you have no knowledge of birds, you can count," Langton said.
Wendi Gladstone of Woodland Hills joined Audubon after her first bird count the day after Christmas seven years ago.
The most recent count also began the day after Christmas, part of a bird count that is held during a two-week period around the world. The count was started nationally 93 years ago as the conservationists' response to hunting during the holidays.
Bird enthusiasts go into an area and count every bird--sometimes from sunrise to sunset--and publish the results in a worldwide guide.