By Laura Goldman From Care2

In San Diego’s Mission Bay, just a short drive from SeaWorld, endangered birds have a protected place to thrive, unperturbed by tourists. North Fiesta Island is home to a dog park, youth aquatic center—and a fenced-off sand dune where California least terns are building nests and raising their young.

Among the threats to these birds’ survival, however, is this habitat itself. Weeds and vegetation can easily take over the dune. This makes the least tern chicks more vulnerable to predators, like crows and ravens, because their light-brown feathers stand out among the greenery. The vegetation makes it easier for the predators to eat the chicks and more difficult for their parents to defend them, Megan Flaherty, restoration program manager for the San Diego Audubon Society (SDAS), told the San Diego Union-Tribune. And the small area of Fiesta Island that the birds are confined to makes them easier for predators to spot.

Fortunately, volunteers with the SDAS’s habitat restoration project help  keep the birds safe by clearing the area of weeds and other plants. “They need open expanses because their eggs and their chicks are both perfectly camouflaged—they blend into the sand,” Flaherty told NEWS 8 last year.

Adult California least terns are about nine inches long, making them the smallest North American terns and explaining the “least” in their name. They have gray and white feathers and a distinctive black cap with black stripes across their eyes to their beaks.

When they’re flying, you can see a black wedge on the ends of their wings. The birds migrate from Mexico to the coast of California in the springtime to mate and raise their chicks, with about 60 percent of them building nests in San Diego County. They return to Mexico in September.

Photo credit: Rinus Baak/USFWS

When the federal endangered species list was created back in 1973, the California least tern was one of the first animals to be added to it. Because these birds were later thriving, with their population nearly doubling since 1973, the U.S. Fish and Wildlife Service(USFWS) has considered downgrading their endangered status to threatened. This means the USFWS is no longer concerned about these birds becoming extinct.

But it probably should be. Flaherty said there’s been a large die-off of California least terns on Fiesta Island, largely because they aren’t able to find enough food. The birds live on a diet of fish, mainly anchovies, that have left the shoreline due to warmer ocean temperatures.

California least terns are essential to the ecosystem, because they deposit nutrients in nutrient-lacking coastal zones, Flaherty told the Union-Tribune. “In ecology, there’s no such thing as an action without consequences because all parts of the ecosystem are connected,” she said. “When you start losing lots and lots of parts of the ecosystem, you’re going to unleash a series of other actions that are going to cascade and potentially release catastrophic events.”

About 120 miles north of Fiesta Island, volunteers are also doing what they can to help other endangered birds thrive in a rather unexpected place. At least 10 rare burrowing owls have made their winter home at the LAX Dunes Preserve, directly under jets taking off from Los Angeles International Experts. Scientists are hoping the preserve becomes their permanent home.

To learn how to help the California least terns on Fiesta Island, visit the San Diego Audubon Society’s website.

Photo credit: Mark Pavelka/USFWS

For more on this story go to; https://www.care2.com/causes/endangered-birds-thrive-on-this-san-diego-island-with-a-little-help.html