To us, the bridge is a way to get across the water, but to cormorants in San Francisco Bay, the old Bay Bridge is home sweet home. And the 800 protected birds currently nesting there are not very keen on moving to the new Bay Bridge span—despite its shiny $700,000 bird "condos." If Caltrans can't lure the cormorants away in time, then the plan to demolish the old Bay Bridge, already behind schedule, could fall off the rails entirely.


Caltrans says it has a $12.8 million plan to get the birds on board—they are considered a "species of special concern" in California—but the results so far have not been promising, according to the SF Chronicle. Although the bird condos, essentially 2 1/2 foot-long steel nesting platforms, went up on the new Bay Bridge span to much fanfare, the cormorants have ignored them.


Ornithologists have also tried adding decoy birds and playing recorded calls to lure the cormorants away. They've even put out nesting materials to the delight of the birds—who have promptly taken it back over to their nests on the old Bay Bridge.

"I'm not going to disparage the birds... but they're kind of like people—moving is hard," said Randy Rentschler, spokesman for the Bay Area Toll Authority. Just as people do not like to be displaced by construction projects, neither do cormorants

In the beginning, Caltrans was smart enough to plan the demolition around the cormorant's mating season—in the same way you might plan it around seasonal traffic flow. That left plenty of time to stop work and put up nets around the old Bay Bridge to keep out birds. But delays have crunched the schedule. If work isn't finished in time, nets can't be put up and the protected birds will lay their eggs on the old Bay Bridge, which then can't be demolished—a whole cascade of delays that will stretch far beyond the planned two years.


Demolition in progress at the old Bay Bridge span

We may build infrastructure for our own convenience, but animals have a way of adapting to the built environment and making it their own. Perhaps this is all a lesson in designing infrastructure for people and animals. Endangered animals have held up construction projects before—the snail dart and the Tellico Dam being one famous example—but this case is different. We built this bridge, unwittingly creating a habitat for endangered birds, and now Caltrans is scrambling to get them to their new home. [SF Chronicle]

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