Birds on the Bay

San Francisco is flooding with tourists. Actually, not those kinds of tourists.

I'm talking about birds - hundreds of thousands of ducks and geese winging their way down from Alaska and Canada for the winter.

The most common are the Greater and Lesser Scaup, dark ducks with white sides, Bufflehead, with their big white patch on the back of their heads, and Ruddy Ducks, small compact ducks with blue bills. We've also got Western and Clark's Grebes, Wigeon, Pintails, Coots, Cormorants, and Loons. A favorite of mine are the Surf Scoters with their white, red, yellow, and black bills. Sadly, these birds have declined a lot of recent years.

Like most visitors to the Bay Area, the birds are here for weather, nice places to stay, and - most importantly - the food. They're looking for herring, clams, mussels, and invertebrates. These things are the foundation for life in the Bay, and are incredibly sensitive to things like oil spills, development, dredging, and illegal moorings.

The smallest mistake from us in San Francisco Bay can upset a migratory chain that stretches for thousands of miles along what we call the Pacific Flyway.

These winter birds will spend most of this winter out on the open water of the bay, where they're hard to see from shore. But you can catch a glimpse of them from places like the Tiberon shoreline, San Pablo Bay and Don Edwards National Wildlife Refuges. 

While they're here, the birds will rest, build some energy, and perhaps even meet their mates before heading north again in the spring to breed. This incredible natural phenomenon is just another reminder that, despite all the human impact, San Francisco Bay remains one of the most important natural places in the Western Hemisphere.

The birds have known this for millennia, and thankfully more and more human residents understand it as well. They're supporting efforts to protect water quality and restoration of habitat - things that are not only good for our winged visitors, but for us as well.

With a Perspective, I'm Brigid McCormack.

Brigid McCormack is executive director of Audubon California. She lives in San Francisco.