Tiny western snowy plovers struggling to survive on Sonoma Coast beaches need space, respect from beachgoers

SONOMA COAST STATE PARK — Tiny shorebirds scattered around the region’s sandy beaches are beginning their nesting season, launching an annual, epic bid for survival invisible to most beachgoers and dependent on it staying that way.

Slightly bigger than sparrows, western snowy plovers nest in the open, laying eggs in shallow depressions on the same beaches that are being used more frequently by human, equestrian and canine visitors as the weather warms.

The federally protected birds are extraordinarily vulnerable. Nesting failures are common.

In many ways, the birds employ the same measures used by shy kids in school to survive: keep to yourself; avoid attracting notice; blend into the scenery as much as possible.

And they’re adept at it.

They are masters of camouflage, with tan, white and darkly streaked plumage that allows them to disappear into the landscape. Their speckled eggs and chicks vanish easily against the sand.

“Their superpower,” avian ecologist Jenny Erbes said, “is invisibility”

But the threats to their survival are increasing — from habitat loss and destruction, to wildlife predation and plundered nests, to forceful winds and whipping sand, to the growing popularity of outdoor recreation.

A random person traipsing through a nesting area unawares could cause adults to abandon a clutch or destroy a nest entirely.

Last week a Press Democrat reporter and photojournalist spotted two skittish birds along the Sonoma Coast. Though not nesting, they were foraging near a popular beach access point, upland from surfers splashing their way back to shore and families coming onto the beach on a sunny afternoon.

Down the beach, a handful of horseback riders blithely tramped across the dunes and onto the upper beach just outside an area roped off because of its potential for nesting.

Once found in abundance between the central Washington coast and Baja California, the Pacific coast population of the western snowy plover has been listed as threatened under the federal Endangered Species Act since 1993.

Only about 2,350 individual breeding adults are now estimated to exist. Federal law prohibits their disturbance or harassment.

Because of development and invasive vegetation, only two dozen nesting areas — half the historic number — are still viable, most of them in California.

European beachgrass introduced a century ago to stabilize dunes and the banks of water channels has crowded the upper beaches where snowy plovers prefer to nest. Rising oceans coming higher up the beach will further narrow the area where they can lay their eggs and teach their chicks to hunt.

Biologists believe litter and food scraps, even the biodegradable stuff, left behind by humans draws predators like skunks, raccoons, coyotes and even other birds into the plovers’ sphere.

Ravens, whose populations have multiplied many times over, have become an especially voracious and omnipresent foe — accounting for a third of all nest failures at Point Reyes National Seashore from 2002 to 2020, according to a national seashore analysis.

People and unleashed dogs can drive adults off their nests, forcing them to use precious energy stores to escape potential harm or drawing threats away from their chicks.

Even birds that stay put likely shift their focus away from where their attention should be to assess a perceived threat, said Erbes, a snowy plover specialist and monitor working under contract to California State Parks.

“We’re sitting on the edge here,” Erbes said Wednesday, noting the influx of visitors headed to beaches with the arrival of fine weather. “It’s getting sunny and warm, and there’s not a lot of space for everyone.”

Park wildlife managers were hesitant even about this story and whether alerting the public to the birds and their whereabouts might draw unwanted attention to creatures that need more than anything to be left alone. (The Press Democrat is not naming specific nesting beaches.)

At the same time, the heavy use of local beaches during breeding season and the narrowing strip of upper beach available for nesting makes it even more necessary to educate the public and have them police themselves to prevent the birds from being disturbed.

Nesting observations from 2020, when COVID closed beaches around the area, provide some reflection of the human presence. At least two Sonoma Coast beaches had nests where none had appeared in recent decades, and another had four birds live long enough to leave the nest, which hasn’t happened on that beach since.

“It’s always that balance between allowing recreation and giving the birds enough space,” said Chris Heintzelman, an environmental scientist with California State Parks.

Snowy plovers “are cryptic, and that was their whole strategy, and it worked because beaches were big and there wasn’t much going on,” he said. “Now that’s changed.”

Though 30 years have passed since the birds were listed, many monitored beaches still have only sporadic nesting. Others have three or four breeding pairs consistently attempting to reproduce. At the Point Reyes National Seashore, there have been 38 to 40 breeding adults each of past three years, wildlife biologist Matt Lau said.

So those trying to enhance their survival are focused on every last clutch of eggs they can save.

That’s why “symbolic fencing” made from posts and fiber rope has been installed around historic nesting areas at several sandy beaches, in a preemptive effort to provide space to the plovers.

Notices are posted as well, and dogs are prohibited, even leashed ones, on some public beaches due to plover conservation efforts. Docents are on-hand at Point Reyes on weekends from Memorial Day to Labor Day to educate the public.

Potential plover mates, their courting behavior and nesting, the progress of their chicks and successive nests are closely monitored and recorded, and may birds are banded, as well, to track populations.

At Point Reyes, biologists are experimenting with cage-like structures that prevent other birds and animals from reaching the nests but allow plovers to come and go.

The structures have raised the nesting success rate “dramatically,” from a range between 5% and 30% to 60%-to-90%, wildlife biologist Lau said.

Heintzelman said a permit for structures at state beaches is in the works, as well.

Still, Lau said, “a lot of people go to the beach, and they don’t even know this bird exists.”

And in some ways, park wildlife managers wish it would remain that way. The lure of something rare is hard for people to resist, and some visitors, Erbes said, will stand at the symbolic fencing looking for plovers “like it’s a zoo” rather than abide by directions to move on and leave them space

“They’re so easily disturbed,” said Sheila Murphy, wildlife management technician at Sonoma County Regional Parks and Doran Beach. “This is really a critical time.”

They’re hoping the public will help with patience and respect for the birds’ plight — leaving them plenty of space and refraining from behavior and removing at least one of the many threats the birds face.

“This is heartbreaking work,” Erbes said, “but every time I want to give up, I just come out and sit with them. And they don’t give up.”

You can reach Staff Writer Mary Callahan (she/her) at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB.