Wildlife experts hope plan to relocate Oakland herons will fly

Black-crowned night heron on 14th at Alice streets on Thursday, April 20, 2017, in Oakland, Calif. Black-crowned night heron on 14th at Alice streets on Thursday, April 20, 2017, in Oakland, Calif. Photo: Liz Hafalia, The Chronicle Buy photo Photo: Liz Hafalia, The Chronicle Image 1 of / 5 Caption Close Wildlife experts hope plan to relocate Oakland herons will fly 1 / 5 Back to Gallery

The more than 250 herons that flock to Oakland every year to breed are in store for a feather-ruffling surprise when they return to their favorite downtown nesting spot in February.

The giant canopies where the long-legged fowl have gathered for nearly a decade are no longer there, and the humans who removed their nests are hoping to lure them to a new breeding ground about a half-mile away at Lake Merritt with decoys equipped with loudspeakers to broadcast recordings of heron mating calls.

The humans insist this is not a bird-brained idea.

“This is ultimately going to be a better thing for the birds,” said Cindy Margulis, executive director of the Golden Gate Audubon Society. “It’s a bird that belongs in Oakland; it just doesn’t belong in downtown streets.”

The herons’ preferred perches have been in the trees shading a cluster of downtown streets, including 12th, 13th, 14th, Alice, Harrison and Jackson. Developers bulldozed many of the trees and trimmed others in early November to make room for two big mixed-use buildings, including one 17 stories high.

Downtown Oakland “wasn’t an ideal spot for the herons, but we can’t control all their choices. All we can do is try and present as many alternatives as possible,” said Lesley Estes, the city of Oakland’s watershed manager.

Mostly known for leaving poop on cars and mail trucks parked under the large trees near a post office at 201 13th St., the birds were first spotted breeding in the neighborhood in 2010 and have returned every year since despite hazards the urban area poses for the chicks they hatch.

In the past year, the Golden Gate Audubon Society rescued more than 65 baby herons that plummeted from the trees onto the concrete jungle below — making the chicks susceptible to being squashed by both foot and vehicle traffic.

“The fact that they’re nesting in these big trees in the middle of Oakland is anomalous,” said Jeff Smith, an associate wildlife ecologist with H.T. Harvey and Associates, an ecology consulting firm that developed the strategy to move the herons.

The city of Oakland required the apartment-building developers to come up with a strategy to move the birds. Working with ecologists like Smith and the Golden Gate Audubon Society, the developers hope their relocation plans flies.

When artist Rick Oginz noticed the crews removing the trees just outside his art studio at Jackson and 14th streets, he angrily called the mayor’s office demanding answers.

“The trees have been a great pleasure to me, as well as the birds,” Oginz said. “I loved watching them coming and going and building nests. I was really upset when I saw the trees going down.”

When Oginz confronted the foreman of the crew cutting the trees, he said, the man explained to him the plan to relocate the birds.

“That made me feel better,” Oginz said. “The bird droppings are kind of a problem for the parked cars.”

A team of ecologists removed the herons’ nests from the trees beforehand and put them into a storage unit in Oakland, displacing an estimated 264 herons, and also 38 egrets.

The nests will be strategically placed in their new living quarters on the shores of Lake Merritt in January, Smith said.

In addition to the nests, Smith will install plastic decoy herons that will begin broadcasting recorded sounds of the bird’s breeding calls in January, ahead of when their nesting season begins in February.

“Now the question is, will this work?” said Estes, the city watershed manager. “The hope is to bring them to a better place to live, to attract them there and to keep them there.”

A similar strategy was used in Long Beach in 1998, when ecologists worked to relocate a large colony of herons from the former Long Beach Naval Station to Gull Park.

There was one notable difference: Workers in Long Beach uprooted 50 trees and moved them to the new nesting location. The plan worked for several years until the birds decided to find their own quarters elsewhere along the Southern California coastline.

In Oakland, Smith tracked down prime real estate in and around Lake Merritt.

Now comes the hard part. The goal is to convince the birds that the lake area and its bird islands are the best spot for them.

The first bird island was built in 1925, and four others were added in 1956 to attract nesting water birds, including herons, according to the city Parks and Recreation Department.

Though the islands lost some of their plush habitat over time, Smith said the rehabilitation of the islands in recent years make them an ideal dwelling for the displaced herons and egrets.

Other locations include a stretch of oak and redwood trees near the northwest edge of the lake.

The move to Lake Merritt won’t be easy, and there are new dangers to consider for the birds.

“There would be mortality in any circumstance. They’re not going to get run over by cars, but they’re going to get eaten by predators,” Smith said, referring to raccoons, feral cats and other creatures that lodge at the lake.

But Smith said he and his team are prepared. They’ve placed barricades around the trees to keep the monsters at bay, and the bird islands also offer some protection and isolation from wildlife looking to feast.

“We may or may not succeed with this effort insofar as there are other alternative locations for these birds to move to” throughout Oakland and the greater Bay Area, Smith said.

Yet they remain hopeful.

Once the decoys are placed and the nesting season starts, the work is not over, Smith said. His team plans to monitor the bird’s progress over the course of the next several years.

And it wouldn’t be the end of the world if the herons follow in the Long Beach flock’s footsteps and find another place to live.

“Let’s just keep our fingers crossed and see what the birds do. It’s an experiment,” Estes said. “I’m glad that we get to do it. I think we will learn a lot.”

Sarah Ravani is a San Francisco Chronicle staff writer. Email: sravani@sfchronicle.com Twitter: @SarRavani