Mattresses, boat parts, toys, cans of insect spray, plastic trash bags, and Styrofoam packing fodder are only some of the trash that the local Audubon Society takes out of San Diego County wetlands every year. The organization conducts regular cleanups near the San Diego River, the Tijuana River estuary, and Mariners Point on Mission Bay.
The Audubon Society's volunteer coordinator Terri Foster relies on 300 repeat volunteers for the work. Many more onetime volunteers, especially from schools, provide additional assistance. Twenty to fifty people show up at each cleanup, says Foster.
Now, for the first time, the San Diego National Wildlife Refuge Complex will allow the Audubon Society to clean mudflats at the Salt Works in Chula Vista. As an incentive for people to attend the December 4 event, the Society is billing it as a chance to do some bird-watching along with the work. Park ranger Debbie Good will lead the participants, who are advised to bring binoculars. An adult must accompany children 13 and under.
The Salt Works is bad news and good news for the wetlands it has occupied on San Diego Bay for nearly 150 years. According to Jim Peugh, chairman of the Audubon Society's conservation committee, the Salt Works "turned the Otay River estuary, with its fresh, brackish, and saltwater, into a narrow-flowing channel. In the process, it destroyed lots of good places for bird nesting. But the less natural environment is productive, too. It has lots of brine flies and brine shrimp, which many different kinds of birds eat for protein."
During the Salt Works cleanup, volunteers will pull out obvious nonnative plants, leaving the more difficult to recognize for experts. I ask Peugh why it's necessary to remove the nonnative vegetation. He cites the behavior of the least tern, a small shorebird on the federal endangered species list. As soon as least terns see predators, they fly up in great numbers.
"But if a lot of plants taller than the low native ones are growing nearby," says Peugh, "the least terns won't nest there. They need to see a predator approaching. When they do, they gang up on it, strafe it, and poop on it. They're very aerobatic. I once saw a gull flying toward a least tern nesting area. It suddenly turned left, went around the spot, and then continued on its way."
Dogs and feral animals in the area used to be a danger to shorebirds before the San Diego National Wildlife Refuge Complex leased the Salt Works from the California Lands Commission. According to the U.S. Fish and Game Service's wildlife biologist Brian Collins, the refuge "acquired use of the property in a trade." Five years ago, Point Loma's former Naval Training Center had a bird-nesting site it wanted to save from the city of San Diego's development plans. The parties involved struck a deal to allow the city to go ahead with development, mitigating environmental damage by allowing the Wildlife Refuge to use the 40 to 50 acres of Salt Works land, explains Collins.
If birders attend the cleanup at the Salt Works, are they likely to be treated to bird sightings they won't get anywhere else? "That would be an absolute way of putting it," remarks Collins. "But bird-watchers are likely to encounter migrating species rarely seen in these parts." He mentions little blue herons, black skimmers, and even peregrine falcons. Black skimmers have a bill that is red at its base and a lower mandible that is longer than the upper.
"Peregrine falcons do live in San Diego County," says Collins, "but they are so fast and dark that they are hard to spot. Gulls are a little too big for them, but they prey on various other shorebirds, such as black-necked stilts." The black-necked stilt is black over the top of its body and has a white belly. It has a long and thin pointed bill.
The Audubon Society's Peugh thinks birders at the Salt Works may see gull-billed terns, which nest at the Salton Sea, and varieties of grebes -- stocky waterfowl that migrate to Alaska in the spring to nest but spend winters in warmer climates. Another Alaskan nester, the long-tailed duck, turns up in San Diego waters in the winter. It is capable of diving almost 200 feet underwater. And long-tailed ducks are known for an elaborate courtship in which males give out a call that sounds like barking. In the spring, they go back to Alaska in pairs.
Especially interesting in coastal waters is the sight of phalaropes "swimming in little circles," says Peugh. "That causes an updraft in the water, bringing to the surface the plankton the birds eat." Phalaropes are small, weighing no more than a tenth of a pound. Males of the species assume the normal female role of caring for the nest and sitting on eggs.-- Joe Deegan
San Diego Audubon Society Salt Works Cleanup
Saturday, December 4
9 a.m. to noon
San Diego Salt Works
Bay Boulevard between Palomar and Main
Info: 619-682-7200 or [email protected]