Just before they hatch, researchers can hear snowy plover chicks chirping and tapping from inside their eggs.
Coastal ecologist Stephanie Coates recorded those noises as she was monitoring nests at the Salinas River National Wildlife Refuge. Each year in late spring, scientists and volunteers try to count every plover on the West Coast.
"It's a rough estimate, but it's the best we can do," she said.
The annual count started more than 20 years ago. Coates has participated for the last five as a researcher with the nonprofit Point Blue Conservation Science.
Researchers put little plastic bands around the plovers’ ankles right after they hatch to identify them. Coates often calls them by their band color combo or what the combo spells.
"There's Baby (blue-aqua-blue-yellow). There's a Barb (blue-aqua-red-blue) down at Monterey State Beach. There's a Rory that I saw last week at (the) CEMEX area: red-orange-red-yellow," she explained, referring to a former sand mine in Marina.
She’s gotten to know the personalities of some of the tiny shore birds. As we walk along the beach, she points out one with a reputation as a "bad dad."
"None of his chicks have made it that I know of," she said.
In plovers, males raise the chicks—usually three at a time. Coates keeps track of all the nests in the area and when they’ll hatch.
Plovers nest in sandy dune habitats, which are threatened by development and sea level rise. Biologists call this narrowing of habitat “coastal squeeze.”
Western snowy plovers were listed as threatened under the endangered species act in 1993 because of habitat loss and human disturbance. Andrea Jones is the vice president of Audubon California. She says the annual count is vital.
"Those results every year help inform conservation efforts on the ground," she said. "A lot of restoration projects are happening along our coastline, and it really gives the opportunity through that data to focus conservation dollars."
She adds there’s also a winter count in California. The U.S. Fish and Wildlife Service collects the results and recently announced a conservation milestone: over 3,000 birds were counted last year.
The population needs to stay there or grow for at least 10 years in order for snowy plovers to come off the threatened list.
Point Blue principal ecologist Kriss Neuman leads the count in the Monterey Bay area. She says the best thing people can do to help plovers is to leave them alone.
"There's pretty good evidence that snowy plovers are sensitive to human use of beaches—so not just development, but recreation," she said.
Neuman says COVID beach closures drove that point home. The plovers started nesting in new places.
"An example from here in Monterey Bay is at Sunset State Beach," she said. "They were way out next to where the lifeguard towers would be placed."
But usually, plovers stay out of sight. Neuman says one of the other challenges people pose for the tiny birds is introducing nonnative grasses that hold dunes in place.
"Pacific Coast dunes are not meant to be stabilized," she said. "They're really dynamic."
The steep slopes the invasive grasses create can block the plovers’ view of predators like ravens.
At the refuge, Stephanie Coates pointed to a bird pretending to be injured to try to distract us from a nest.
"That’s a lure display," she said. "See how the tail is spread out? She's hiding, flattening herself on the ground."
Coates has a permit to approach the nest. One at a time, she places each egg into a cup of water to see how it floats and estimate age.
"As the chick develops in the egg, an air bubble forms and gets larger, so the egg will start to tilt upward—wide end upward—and then break the surface of the water eventually," she said.
That’s when Coates knows the tapping and hatching is coming soon.
It’s the 76th nest in that area this year. Scientists are cautiously optimistic for the plovers. They say the little birds are remarkably resilient and help illustrate that even beaches that look deserted are full of life.
