Like a bower bird desperately seeking to attract a mate, Caltrans and other agencies have spent perhaps lavishly to maintain the habitat of the double-crested cormorants who made their nests on the old Bay Bridge span. In fact, the MTC even scheduled phases of the demolition of the old eastern span so as not to interfere with the birds' annual nesting season. Doing so reportedly cost millions to the state, but the cormorants are a state-protected “species of special concern" and legally require such accommodations. Was that sum and the $1 million spent trying to induce them to shack up beneath the new span of the bridge, using bird calls over outdoor speakers, decoy cormorants, and more, really worth it? Should $709,000 have been spent on stainless-steel nesting platforms where the birds have yet to perch?
“We really thought when the old span was removed, they would choose to move over to the new span,” Metropolitan Transportation Commission spokesperson Randy Rentschler tells Matier and Ross, who went birding for their latest Chronicle column. “We did our best, but they didn’t.”
Despite 12 years of noisy construction on the new Bay Bridge span that began in 2002, the cormorants never departed their nests. But in 2009, perhaps due to a population crash of northern anchovy, a staple food for the cormorants, the birds failed to breed, and bridge colonies declined to 252 nests from a height of 1,296 in 2007. That's according to accounting by seabird biologist Mark Rauzon in the April-June issue of Bay Nature magazine.
Rauzon calls the cormorants #8217;an “only in San Francisco” story: "The Bay bridges [the Bay Bridge and the Richmond-San Rafael Bridge] have provided the cormorants with both benefits and challenges... They got a short commute to feeding grounds and a cool place to nest, but they have also had to contend with required bridge maintenance." It seemed likely that some of the displaced cormorant colony would flee to the Richmond-San Rafael Bridge, but that structure's underside was closed off for construction and maintenance.
"Our urban cormorants are at a crossroads. Where will they turn?" Rauzon asks. "Will they learn to live on the new bridge? Relocate to the South Bay salt ponds? Fly out to the Farallones, or wait out the Richmond Bridge work? I hope that once the old Bay Bridge is gone some genius cormorant will discover that the new bridge platforms are open, and the colony will begin to settle in."
It's possible that some are already on their way: Wildlife monitors confirmed two cormorants have landed, the Chronicle reports, and were enjoying their new accommodations. “Too early to know yet if this will lead to actual nesting on the platforms," Retschler told Matier and Ross, "but hey, ‘Woo hoo!’”
Finally, Rauzon appears to think Matier and Ross are ruffling feathers where there's no real scandal. "Phil Matier of the San Francisco Chronicle harped about the half-million-dollar price tag," Rauzon writes, seeming to refer to the nesting platforms alone, "but Caltrans was in fact complying with the Migratory Bird Treaty Act. If nothing were done, the birds would relocate to the Richmond-San Rafael Bridge and the power towers of the South Bay, adding greatly to those maintenance costs. Public money would likely have to be spent one place or another."