Birds on the Bay Bridge


Hundreds of cormorants nest below the roaddeck of the old Bay Bridge, and bird monitors with CalTrans are trying to figure out how to get them to leave. (Photo courtesy of CalTrans.)

Of all the birds that nest on or around the Bay Bridge—gulls, terns, pelicans, pigeons, falcons, hummingbirds—Lauren Bingham is most concerned with the cormorants. It’s not that they’re worse, bird by bird, more onerous or unruly than the other birds; it’s just that there’s so many of them.

Standing on the unopened new span of the Bay Bridge, halfway to Yerba Buena Island, she points at the steel latticework right below the road deck on the old bridge, then gestures back toward Oakland. Cormorants the whole way, she says. “They love it,” she says. “I think the visibility is good.” A black, bowling-pin-shaped bird swoops down towards the water. Traffic is a steady roar. “They don’t seem to mind the noise,” she says.

Bingham, who works for Ganda and Associates, is one of a dozen biologists who track all the birds on the old bridge and its new, LED-bedazzled sister span. They’re subcontractors with CalTrans, and their job to make sure the construction crews don’t violate federal and state law by bothering the birds. The main law, the Migratory Bird Treaty of 1918, protects more than 800 species of birds. It says you can’t hunt them, or poison them, and if you’re working on a construction site, you’re not allowed to run them over with a bulldozer.

On construction sites, it’s okay to flush a bird from its roost and raze its nest as long as it isn’t full of eggs. But if the gulls do manage to build a nest and lay an egg, it’s illegal to disturb it—the biologists mark off buffer zones, or put up plywood blinds. Then they, and the construction crews, wait until the chick has fledged. That’s why, Bingham says, it’s usually best for both parties if the birds don’t build a nest in the first place.

Birds can be a hindrance on all construction projects, but the headaches increase with the size of a project—and the Bay Bridge project is one of the biggest in the country.  Spring is nesting season, so the scientists are on high alert to prevent gulls and other birds from making a home on the top of the new bridge, where they could get in the way of the construction workers hustling to finish the bridge before September. The scientists work for several environmental consulting firms, each with a slightly different role—one team boats around in a skiff, checking on the birds near the water; others conduct patrols of the road deck every few days.

Bingham stands with Eric Lichtwardt, another biologist. “As you drove up here there were a couple pairs of Western Gulls hanging around, looking suspicious,” he says to her. “We’re keeping our eyes on them.”

William Howe, one of the lead engineers overseeing the Bay Bridge project, says that working around the birds is just part of the deal. “It’s just a question of knowing what the rules are and then following the rules,” he says. “It’s not like we have people that are trying to hide the fact that they are impacting birds, kicking eggs off of nests.” During the 10-year project, the birds haven’t caused too many problems or delays, he says.

But he’s not sure what will happen with the cormorants already living underneath the older span. The old bridge’s cormorant infestation is a special problem, Bingham agrees. The day the new bridge opens, crews will start tearing down the old one. About six years ago, anticipating the problem, CalTrans installed shelves on the underside of the new bridge, hoping to attract the cormorants. The shelves, meant to offset the destruction of the birds’ habitat, won’t be visible to people driving on the bridge. So far, though, the $550,000 worth of “cormorant condos” haven’t paid off. Neither the fake cormorants resting on the shelves, nor the speakers blaring warbly cormorant mating calls have attracted any real cormorants.

If the birds don’t move on their own, Bingham says, they’ll probably have to be evicted, shooed out of the way of the crews tearing the bridge down.

She gets in her car and drives over to another biologist, who is peering through a scope at a peregrine falcon. “She’s facing us, she’s got a big white crest,” biologist Eric Jepsen says. “She’s really far away.” He’s been standing there for about an hour, taking notes on the bird’s activity and location. She’ll lay an egg in the next few days, he predicts. (“Egg-heavy” is the correct term for birds, he says, not “pregnant.”)

Jepsen will probably be there another hour, maybe more, before he moves on to spy on the cormorants for a while. “Biology in general is 90 percent boring, or 99 percent boring,” he says, then nods in the direction of the bird. “She turned around a minute ago and preened. It was a very exciting moment.” The biologists laugh.

But the biologists say they’ll be sad when the gig’s over—the Bay Bridge is one of the biggest construction projects in the country right now, with the most birds, and the most challenges for bird monitors. Bingham says the next job is sure to feel small after this one.

“You’re gonna be like, ‘You only have one bird?’” she says. “Come on!”

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