California Least Tern Updates and Photos

The Port's Endangered Species Management Program provides enhanced nesting and foraging opportunities for the federally listed endangered California least tern (CLT).

This ongoing program includes the implementation of controlling access to nesting sites; site preparation and vegetation control; predator control, ant predator control; public information programs, and monitoring programs. Nesting sites on Port tidelands include the D Street Fill, Chula Vista Wildlife Reserve, and the South Bay Salt Works. The San Diego County Regional Airport Authority manages San Diego International Airport and the Chula Vista Wildlife Reserve.

2008 California Least Tern Report

2009 California Least Tern Updates

Some of these pictures of least tern chicks were taken at the San Diego International Airport by Mayela Padilla. The hands belong to Robert Patton, a biologist employed by the Zoological Society of San Diego. He is the only one allowed to handle the chicks.

In its role as environmental steward of the tidelands around San Diego Bay and a swath of oceanfront in Imperial Beach, the Port oversees a number of species and wildlife preservation programs. One of the most successful programs is the protection of the endangered California least tern (Sterna antillarum browni). Historically, the nesting site at the Port’s wildlife reserve areas in Chula Vista has had one of the highest percentages of surviving fledglings in San Diego County.

“We attribute the higher productivity to the enhanced habitat quality on the east side of San Diego Bay,” said Robert Patton, consulting biologist with the San Diego Zoological Society. The Port has contracted with the Zoological Society since 1997 to monitor and provide protection for the endangered California least tern.

Around April every year, the birds arrive at their ancestral nesting areas in Southern California, which includes the Port’s wildlife reserve areas in Chula Vista. Favored tidelands nesting sites for these migrating birds include the Chula Vista Wildlife Reserve and the Sweetwater Marsh National Wildlife Refuge. Nests are small depressions scraped in the beach sand. The females lay one to three well-camouflaged eggs. Robert Patton and his team of biologists visit these nesting sites twice a week to count eggs and band hatched chicks. Newborn chicks fledge quickly and are able to fly in a few weeks. To boost the survival rates of the vulnerable chicks until they fledge, staff from Wildlife Services and UC Riverside keep a close eye on predators in the area.

Many environmental projects that have been funded by the Port, such as restoration of eelgrass and storm water runoff controls, have boosted the survival rate of the young terns by providing cleaner bay water and abundant fish species for feeding the chicks.

“The least tern nest numbers and pair numbers have generally increased on Port tidelands over the years,” said Patton. “We consider the Port’s least tern program a success.”