Helping save the California Least Tern
It's always so wonderful this time of year to hear all the various birds and their calls reinvigorating the air in and around Venice. From the screeching calls of the sea gulls to the marauding wild parrots [ka-kau, ka-kau], the ubiquitous crows [caw-caw], mockingbirds [tcheck tcheck], sparrows [spr-spr-spr tseet], tiny hummingbirds [whrr-whrr-whrr], ducks [quak quak quak], blue jays [jeee-ah eeh-ah keerk], and mourning doves [coah, cooo cooo cooo]. Among many others.
But the sweetest music to my ears is the klee-ip and kee-zink, kee-zink of the Least Tern (Sternula antillarum). This gray and white seabird with long, narrow, black-tipped wings and a black cap holds a favored place in my heart because of the efforts of local citizens to bring this bird back from the edge of its "Endangered" classification.
The U.S. Fish and Wildlife Service listed the California Least Tern as an Endangered Species on October 13, 1970, with a population of about 600 pairs. With aggressive management, the Californian population has rebounded in recent years to about 4,500 pairs, a marked increase from 582 pairs in 1974 when census work began, though it is still listed as an endangered subspecies. While numbers have gradually increased with its protected status, it is still vulnerable to predators, natural disasters or further disturbance by humans.
This small bird, about 9 inches long, is a wonder in appearance. The upper parts are a fairly uniform pale gray, and the underparts white, with yellowish legs. The head is white, with a black cap and line through the eye to the base of the bill, and a small white forehead patch above the bill. The bill is yellow with a small black tip in summer. In behavior, it flies over water with fast, jerky wing beats and a distinctive hunchback appearance, with the bill pointing slightly downward. When flying the wingbeats often are so rapid that they cannot be counted.
The Least Tern hunts primarily in shallow estuaries and lagoons, where smaller fishes are abundant. They hover until spotting prey, and then plunge into the water without full submersion to extract dinner. In the bays and lagoons of Southern California and northern Mexico, the favored prey include anchovy, smelt, silversides, shiner surfperch and small crustaceans. Sometimes the terns feed near shore in the open ocean, especially in proximity to lagoons or bay mouths. When feeding, the terns often follow schools of fish north and may be seen fishing off the southern coast of Oregon.
California Least Terns presumably winter in southern Mexico, Central America or northern South America, although their wintering range remains unknown. The Least Tern arrives at its breeding grounds in late April. The breeding colonies are not dense and may appear along either marine or estuarine shores, or on sand bar islands in large rivers, in areas free from humans or predators. Courtship typically takes place removed from the nesting colony site, usually on an exposed tidal flat or beach. Only after courtship has confirmed mate selection does nesting begin by mid-May and is usually complete by mid-June. The birds leave around August or September.
Once considered abundant, the California Least Tern has suffered dramatic declines due to human encroachment and destruction of its nesting habitat. Formerly these terns regularly nested on sandy beaches and mudflats near the ocean. However, human disturbance related to dredging and development projects have drastically reduced tern-nesting habitat. The construction of the Pacific Coast Highway in the early 20th century had a significant impact on California Least Terns, as well as other shorebirds, by directly destroying nesting beaches as well as making these areas more accessible to human encroachment. Today, the construction of housing developments continues to reduce suitable breeding grounds, and many remaining tern populations choose to nest on mudflats away from the ocean and man-made landfill instead.
Historically, they nested in several small, scattered aggregations on sandy beaches and salt flats along the California and Baja California coast, although the progressive loss throughout this and last century of undisturbed sandy beaches resulted in a severe reduction in both nesting sites and numbers of nesting pairs. By the 1940's, terns were gone from most beaches of Orange and Los Angeles counties and were considered sparse elsewhere in the state. There are only two sites left in Los Angeles County, Marina del Rey - actually Venice Beach around Union Jack Street - and at the Port of Los Angeles.
So that's what that fenced-in area near the end of the marina peninsula is for. I always wondered why this area, approximately 120' x 160' in size, was closed to the public. And little did I know that this pristine beach site was the chosen location for these winged-wonders to nest and thrive.
Least terns have nested in the Ballona Creek wetlands since at least 1894. They occupied the beach near the current enclosure between the late 1800's to the early 1920's. Between 1933-1953 they occupied nearby Playa del Rey on the south side of the Ballona Creek channel. In the 1970's they moved to the mudflats inland of Playa del Rey. Researchers began to study this colony intensely in 1973 after having been listed on the endangered list. Flooding of the salt flats due to rain early in the 1977 nesting season apparently prompted birds to nest for the first time on the beach at the enclosure. They have nested on the beach at Venice since 1977.
That year, three pairs of California least terns were discovered nesting at Venice Beach, north of Ballona Creek. A temporary enclosure was immediately set up to protect the colony. Temporary fences were used again in 1978 & 79. After predation by a dog in 1980, a permanent fence was put up in 1981; a new enclosure was completed in March 2006. This is where I now go to observe them.
Since re-establishment, the Venice Beach Colony has supported up to 16.6% of pairs of breeding least terns statewide, and over 30% of statewide fledglings. Since 1999, numbers have been highly variable and the colony has failed to produce fledglings in four of the past 7 nesting seasons. 1999 and 2001 were bad years for least tern productivity statewide. This has lead to great concern among wildlife managers over the long-term success and stability of this colony. Fortunately, 2007 was a very successful year with nearly 550 nests producing between 400 and 450 fledglings. Thanks to the efforts of the local Audubon Society, this enclosed space on the beach has guaranteed a recurring nesting spot for these fragile birds.
Here's how you can help protect the Least Terns in 2008. Volunteer monitoring is scheduled from April 15 to August 15. Volunteers will spend approximately 1-2 hours one day per week watching and counting the terns and their chicks. Training is provided Saturdays from 9 am - 3 pm. For more information on how to be a bird-conscious volunteer, contact Los Angeles Audubon at firstname.lastname@example.org and www.laaudubon.org.