Just a stone's throw from two of Los Angeles' busiest freeways lies the Sepulveda Basin Wildlife Reserve, a unique spot in an urban jungle.
The northern portion of the reserve is adorned with 30-foot-tall cottonwood trees, spots of coyote bush and other plants. Native plants cover 50 percent of the nature spot, says Kris Ohlenkamp with the San Fernando Valley Audubon Society.
"On the other side it was significantly more than that," he says.
A cement corridor leads to the southern part of the reserve. "This 48 acres was the original wildlife area," Ohlenkamp says, "and now it's all gone."
Flattened trees, branches and bushes are scattered like a game of pickup sticks as far as the eye can see. Raised tire treads from heavy machinery lattice the ground in all directions.
Dave Weeshoff, who is also with the Audubon Society, says this area decades in the making provided food, shelter and a breeding habitat for wildlife and more than 200 species of birds.
Weeshoff says this is only Phase 1. Herbicides will be spread to prevent anything from growing. "This is going to get bad and then even worse," he says.
The U.S. Army Corps of Engineers manages this portion of the Los Angeles River flood plain. Tomas Beauchamp, an official with the Corps, says the agency tried multiple tactics to address current issues in the area.
Beauchamp says the clearing was necessary to improve flood-control operations and public safety. Under its vegetation management plan, he says, the Corps will replace what was removed with native grasses to discourage homeless camps, drug dealing and lewd activity. He says the Corps did approach law enforcement about the problems in the area.
"This was like a hurricane went through there," says California state Sen. Fran Pavley, whose district includes the reserve.
She has asked the Corps to explain a finding it had that no wildlife or habitat would be significantly disturbed by the clearing.
"It looked like extensive unneeded devastation of acres and acres of land," Pavley says, adding that "the public felt they had no knowledge."
The Corps says it posted notice of the project on its website but received no comments. Under pressure from politicians, other government agencies and environmentalists, it has temporarily halted work.
U.S. Rep. Brad Sherman (D-Calif.) says moving forward requires balancing the interests of public safety and the environment.
"First is flood control, but beyond that anything that can be done both to provide habitat for wildlife and viewing opportunities for valley residents is important," he says.
Now, in an area where the California thrasher would be in full song at this time of year, setting up its territory to attract a mate, there's hardly a chirp. In the thrasher's absence, Weeshoff pulls out his phone and clicks on an app that plays the bird's call.