L.A. County tests plan for bird-friendly plant maintenance at parks

The distress call of a marsh wren at Los Angeles County’s busiest park has led to an experimental maintenance plan that favors birds by restricting tree trimming and vegetation cutting to winter seasons.

Los Angeles County Parks and Recreation officials revamped maintenance strategies at Legg Lake in South El Monte’s Whittier Narrows Recreation Area after bird watchers complained that a cattail removal effort had disturbed a marsh wren.

Now, with the approval of state and federal wildlife authorities, the county aims to make the park as peaceful and comfortable as possible for its avian visitors.

“The beauty of this plan is not so much what we are doing as what we are no longer doing,” said Mickey Long, the department’s natural areas administrator. “Essentially, we’re pushing maintenance work into the winter months and out of nesting seasons in spring and summer.

“But no matter what time of the year it is, if a bird is nesting nearby, we will stop trimming and cutting,” he said.

Under the plan, one of the park’s three man-made lakes has been declared a wildlife preserve where future vegetation clearance work will carefully target non-native species. “That lake’s two islands are now regarded as bird sanctuaries,” Long said.

In addition, bird-viewing stations will be installed in areas where great blue herons and double-crested cormorants build enormous nests each year in the limbs of 100-foot-tall eucalyptus trees at the water’s edge.

Vegetation at the other two lakes will also be managed to protect wildlife and enhance habitat. However, those lakes will continue to allow recreational activities, including model boat racing and pedal boat rentals, officials said.

“This plan does not preclude safety work that needs to be done, such as removal of a hazardous limb from a tree,” Long said. “We also intend to maintain a clear waterway in each of the three lakes for trash removal and emergency response by boat.”

If successful, similar strategies will be adopted in other regional parks, including Frank G. Bonelli Regional Park in San Dimas and Castaic Lake State Recreation Area.

Word of the new management plan in the Whittier Narrows area, a lush pocket of remnant willow stumps, sycamore groves and grapevines where the San Gabriel and Rio Hondo rivers converge, was welcomed by naturalists and birding enthusiasts.

“Managing county parks in a manner that promotes wildlife and biodiversity is a step in the right direction,” said environmental consultant Dan Cooper. “This section of Los Angeles County embraces some of the most biodiverse public parklands in the United States.”

In June, Cooper spotted a yellow-billed cuckoo less than a mile from Legg Lake. The species was last recorded there in 1952.

“It’s obviously advantageous not to disturb habitat during the nesting season, when it is easy to disrupt and destroy an entire breeding season’s efforts,” said Kimball Garrett, manager of the ornithology collection at the Natural History Museum of Los Angeles County. “It is also nice to know that government agencies can be responsive to the concerns of observant citizens.”

The issue was first brought to the attention of county officials in February by Michael San Miguel, an ardent conservationist in Southern California field ornithology, who died in July.

“Michael heard a marsh wren call out from a stand of cattails that was being cut down,” Long said. “That bothered him so he sent out e-mails to Audubon chapters and county officials.”

“In cooperation with the California Department of Fish and Game and the U.S. Fish and Wildlife Service, we came up with this plan,” he added. “I also handed out copies of the ‘Los Angeles Audubon Guide to Bird-Friendly Tree and Shrub Trimming and Removal’ to each of our maintenance units.”

In June, a copy of the management plan was dispatched to San Miguel. A short time later, “I learned that he had died,” Long said.

“In Mike’s honor,” Long said, “we came up with the best possible management plan.”

louis.sahagun@latimes.com