by Matthew Warner
This post is the ninth in a year-long series celebrating the 40th anniversary of the Endangered Species Act. Read the previous post here.
For decades San Francisco Bay’s marshlands were viewed as a waste of space, so they were drained and filled in for development. However, we’ve come to learn that our tidal marshlands serve a number of important functions: They help prevent flooding by their ability to adapt to the rise and fall of water. They help keep our waterways clean by filtering pollutants. And they provide critical habitat for a number of critters.
If you are ever in the neighborhood of Larkspur and have time to take a stroll by Corte Madera Creek, you just might hear or see a clapper … no, not the part of a bell or the sound-activated switch as seen on TV (“Clap on, clap off”), but the California clapper rail (Rallus longirostris obsoletus).
The California clapper rail is listed as an endangered species. One reason their numbers are in sharp decline is the loss of habitat due to the diking that converted low-lying marshland into urban development. Another factor leading to their sharp decline is the predation of eggs by non-native foxes and rats. As adults, they have to keep a sharp eye on the sky as they are hunted by red-tailed hawks, northern harriers and peregrine falcons. It would have been “Clapp off” for the clapper rail if it wasn’t for the US Fish and Wildlife Service, which made a recovery plan in 1984 and is aiding in the recovery of the bird’s population.
Clapper rails nest close to the water’s edge and enjoy feasting on spiders, yellow and striped shore crabs, amphipods and the introduced non-native horse mussel. When you are out walking the creek you can thank the California clapper rail for taking out the horse mussel from our waterways! Feel free to watch and take pictures, but remember to keep a reasonable distance away from the birds so as not to disturb them.
The California clapper rail is yet another reason among many for us to support efforts to keep our salt waterways clean and to restore our tidal marshlands, which help prevent flooding and purify our water. Happy observing and “Clapp on” for the California clapper rail!