In San Diego world-class means saving a little bird

Eileen M. Maher
Assistant Director, Recreation & Environmental Services
Port of San Diego
San Diego, California

At the Port of San Diego, employees share a vision of being world-class through excellence in public service. They measure world-class not in terms of facility size, numbers of containers or tons of product, but rather in service to their community and environment. The Port, which receives no public subsidies or taxes, provides $8.4 billion of economic impact to the San Diego region. Its processes are a model of openness, transparency and public participation. Most importantly, this agency has embraced its role as environmental steward of San Diego Bay's natural resources.

In its quest to be world-class, the Port has learned that the public values and desires a clean bay and healthy ecosystem. As a result, the Board of Port Commissioners has adopted a policy to balance regional economic benefits with environmental stewardship. For example, this public agency is now a leader in enhancing natural resources and protecting endangered species of San Diego Bay. The Port's Environmental Services Department is actively supporting several endangered species programs, including protection of the light-footed clapper rail, green sea turtle, western snowy plover, and the California least tern.

By far the majority of the Port's efforts are directed at the protection of the endangered California least tern (Sterna antillarum browni). This small sea bird, dependent on pristine beaches for survival, has fallen victim to the loss of suitable habitat due to growing population and coastal development. The California least tern was declared endangered in 1973.

The Port is working cooperatively with the California Department of Fish and Game, U.S. Fish and Wildlife Service, and the University of California, Riverside to protect the least tern and its habitat along San Diego Bay. The Port has also partnered with the Zoological Society of San Diego to assist in managing nesting populations of least terns on Port lands around San Diego Bay. This resulted in a contractual arrangement whereby Conservation and Research for Endangered Species (CRES) administers habitat management and monitoring activities for the Port. In addition, predator control at least tern nesting sites is provided by the U.S. Department of Agriculture, Wildlife Services. Wildlife Services has live-trapped skunks, feral cats and dogs, raptors, raccoons and coyotes. Specialized research is being conducted at U.C. Riverside into the control of ant species that can puncture and predate least tern eggs prior to hatching or attack newborn chicks before they are able to walk.

The first action taken to help the endangered least tern was the creation of a safe haven for their nesting activities. This was accomplished cooperatively between federal and state resource agencies and the Port of San Diego. The Port has set aside sandy shoreline property along San Diego Bay as protected wildlife reserves. These areas—the Chula Vista Wildlife Reserve and land adjacent to the Sweetwater Marsh National Wildlife Refuge—are now favored nesting sites for the least tern. To ensure that these areas remain productive, the Port controls invasive weeds and occasionally imports select beach sand favored by the least terns for nesting.

Human access to these sites is strictly controlled. Among those authorized to access the reserves are researchers monitoring least tern nesting activities. Their work begins in April, when the least terns start to return to San Diego Bay, and typically ends by July, when new chicks have fledged.

About three to four times a week, a three-member monitoring team searches for evidence of least tern nesting activity. It requires a trained eye because everything the least tern does is small and camouflaged. A typical least tern nest is a small, shallow depression scraped out of the sand, about the size of a cupped hand. That may seem tiny, but it is just the right size for the least tern, the smallest of 39 species of terns. An adult least tern is only about nine inches long, bill to tail, and has a wingspan of about 20 inches and weighs in at about 1.6 ounces (45 grams).

Least terns lay one to three eggs, which both parents take turns incubating. The eggs are a speckled buff color that mimics the sandy surroundings. The eggs are so well-camouflaged that the team has to stay ever-vigilant not to step on them. Least tern chicks hatch after a 21- to 28-day incubation period.

The chicks, like the eggs, are camouflaged. Shortly after hatching, the chicks develop a sandy-colored down that is patterned with dark flecks on the back to look like beach sand.

Having an ample food supply is critical to the successful fledging of the vulnerable least tern chicks. The least tern feeds on a variety of small fish that inhabit San Diego Bay and its tributary marshes. Fish are caught by hovering a few feet above and then plunge-diving into the water. To do its share in helping the least tern find adequate food, the Port partners with federal and state resource agencies to protect, preserve and enhance the natural bay environment. Working cooperatively with these agencies, the Port of San Diego has environmental programs to improve water quality of the bay, restore intertidal habitat and create new areas of eelgrass, which provide effective fish nurseries.

When the research team finds newly hatched least tern chicks, they include detailed information about the chicks in their monitoring report. Specially trained and authorized to handle least terns, researchers carefully examine the chicks to determine their general state of health. The chicks are weighed and banded. One to two days after hatching, chicks typically weigh only about six grams, about the same as a new U.S. quarter. These diminutive least tern chicks grow fast, however. Within about three weeks they can fly and will have increased their weight to about 30 to 35 grams.

The Port of San Diego is a leading partner in these enhancement and protection programs for San Diego Bay. However, questions always remain whether this special attention afforded the endangered least tern is making a difference. Are environmental enhancement projects and protection efforts reaping hoped-for rewards? As with most attempts to revive endangered species, the results are mixed and year-to-year reproduction rates can vary significantly. Global events, such as El Nino-related weather and oceanic conditions, can severely reduce the least tern's food supply and curtail reproduction rates. Since 1973, when the California least tern was declared endangered and only about 600 breeding pairs were estimated to exist, meaningful progress has been made to prevent extinction of this small seabird. By the year 2000, breeding pairs were estimated to number about 4,600.

Even with this progress, the California least tern remains endangered and will continue to need intervention from the Port and its federal and state partners for its survival. Urbanization and loss of habitat continues along southern California coastal areas. However, the Port of San Diego is proud of its role in protecting the least tern. On reserves set aside by the Port, the overall numbers of nests and breeding pairs have generally increased and its least tern protection program is considered a success. This success is but one element of the Port's vision of world-class.

For more information about efforts to protect sensitive habitat and endangered species, including the least tern, check these Internet links:

Eileen Maher directs and coordinates the Port of San Diego's environmental restoration, protection and mitigation programs. She works directly with state and federal resource agencies to safeguard and enhance the natural resources of San Diego Bay. The Port of San Diego is a public benefit corporation created in 1962 by state legislation and serves as trustee of the State of California tidelands around San Diego Bay. Eileen can be reached at (619) 686-6532 or