With fewer people on the beach, shorebirds may spread their wings

If you head to the beach, keep your eyes open: You may encounter some coastal dwellers who have ventured into new territory during the closures.

While most Californians are under coronavirus stay-at-home orders, shorebirds such as endangered least terns and threatened snowy plovers may benefit from the hiatus of humans on San Diego County’s shoreline. It’s migration and nesting season, so birds are at the peak of activity, and some may spread to unoccupied beaches.

“The least terns are arriving now; they’re just getting to all the nesting sites,” said Kevin Clark, director of biological services at the San Diego Natural History Museum. “They really want to nest in beaches, but normally can’t. It will be interesting to see where they nest, if they have all this empty real estate if the beaches are closed.”

Sue Smith, a research fishery biologist and expert birder, said the COVID-19 closures haven’t left much opportunity for bird watching. But on one recent outing, she spotted something new at Del Mar North Beach, where canine visitors normally rule the roost.

“I was there a day or two after the closure and could see a flock of royal terns already perched happily on the beach, plus western, California and ring-billed gulls, and also shorebirds: willets and a few whimbrels,” she said. “First time I have ever seen them perched there. So the birds learn fast when these loafing spots clear up for them!”

As beaches reopen for some activities, biologists say people will have to be careful to protect not only each other but also the shore-nesting birds sharing the space.

The adventures of wildlife in the absence of humans has drawn attention to reports of goat herds traipsing through Welsh villages and of bobcats and bears enjoying a tourist-free season in Yosemite Valley. It makes sense that birds and animals would behave differently when people aren’t around.

Scientists caution, however, that population-level effects on wildlife would take much longer than a month or two to occur, and would require long-term study to document. Moreover, the very closures that could open opportunities for fertile nesting seasons or new patterns of predation also prevent us from observing those changes.

Parks, trails, beaches and lagoons have been closed for a month or more, and even the most avid birders and devoted wildlife watchers say they have been out of the loop of those environments.

“Unfortunately, since the citywide trail closures, including our trail, we have not been able to be on the trail for the last six weeks or even at the nature center,” said Paula Kirpalani, a board member for the Batiquitos Lagoon Foundation. “I’m guessing since people aren’t walking the trail, there is probably more animal activity during the day since the animals have the trail to themselves.”

Birds are en route along the Pacific Flyway, but it’s hard to say whether there are unusual numbers or unexpected species in the mix this year, experts said. After a rainy spring there are plenty of water sources to sustain the migrants, so it would be a good year for bird-watching if you could get out on trails to see them.

“I am not noticing any obvious differences where I am going, but I am not going to half the usual places I go due to closures,” said Paul Lehman, a veteran San Diego birder. “There are lots of spring migrant land birds passing through this month, one of the best years in a long time.”

Clark said rare shorebirds such as least terns and snowy plovers could be freed from their isolation as we remain in social-distancing mode. The birds’ nests are simple depressions in the sand, and are vulnerable on crowded beaches.

Scientists maintain protected areas for least terns at local lagoons and on San Diego Bay, where they are safe from predators and people who threaten their eggs. But those areas aren’t their preferred habitat, he said.

“For the most part, they want to fly out to the ocean where the fishing is,” he said. “Historically, they want to be right on the beach, in the sand dunes. They’d much rather be in Mission Beach or Coronado Beach.”

With foot traffic down, terns might recolonize those prime areas, he said, spreading out across the San Diego County shoreline instead of sheltering in the preserves.

“As they arrive, maybe they’ll think that the beaches look a lot nicer than these protected areas we have for them,” he said.

Snowy plovers hunt for small crustaceans on the shoreline and must nest near the water. But since most beachfront in San Diego and neighboring counties is crowded with people, they stay mainly within fenced preserves on Silver Strand Beach.

“They have to forage along tide lines to feed their chicks,” Clark said. “They have very little nesting area left in Southern California. They’re going to be expanding out to use these areas that people aren’t using anymore.”

Expanded nesting grounds could be jeopardized by renewed beach use, however, as San Diego County coastal cities roll out plans to reopen beaches over the next week.

Still, large groups won’t be allowed, and social distancing restrictions — imposed to prevent COVID-19 infection — could also safeguard ground-nesting birds. Beachgoers should be aware of possible nest sites and steer clear of them if they see them, said Hans Sin, a senior environmental scientist with the California Department of Fish and Wildlife.

“The big thing we want to let the public know is to be cautious if you do encounter wildlife, and to tell the lifeguards where they are, so that we can have information on them,” he said.

In addition to notifying lifeguards or other authorities about shorebird nest sites, beach-goers can report sightings on apps such as eBird or iNaturalist, which scientists use to help map and monitor wildlife.

“The biggest concern is giving them space as far as nesting, and if you are recreating with dogs, to make sure they are on leash, and to make sure that we can give them the best chance at reproduction that we can,” Sin said.

There are other possible outcomes of the closures orders on wildlife, Clark and others said. Roadkill may decline because of drops in vehicle traffic, he said, which could lead to fewer deaths of small animals such as reptiles and rodents, and “even rare species like ring-tail, foxes, mountain lions and bobcats.”

Predators could be winners as well, with hawks and other raptors getting a better shot at squirrels in typically crowded spots such as Balboa Park.

Last weekend, the San Diego Museum of Natural History helped host the City Nature Challenge, a citizen science event in which cities around the world tally plant and wildlife sightings over a four-day period, vying for the greatest diversity.

Outdoor enthusiasts in the Americas, Europe and Asia capture images of local flora and fauna, then upload their photos on the iNaturalist app for verification. In the past it has run as a competition, and last year San Diego took third place for both biodiversity and total sightings. This year, it was re-imagined as a celebration of nature amid the global health threat.

Participants said it was tough to find places to observe nature that weren’t shut down or occupied by hikers or recreationists who turned to open space preserves after city and county parks were closed, said museum spokeswoman Rebecca Handelsman.

Patricia Simpson, an avid iNaturalist user, had planned a whirlwind circuit for this year’s City Nature Challenge, traveling from Cabrillo to Mission Trails, Mount Laguna, Anza Borrego and Palomar.

“Covid-19 changed all that, but I was amazed about how much I could do right here!” she said.

Mary Duffy, a regular iNaturalist user and an outreach director and biologist at Earth Discovery Institute, said she missed the “joy of discovery” that comes from interactions with other nature watchers during the City Nature Challenge.

But she added that San Diego was “lush and green, and water flowing everywhere,” which created excellent conditions for viewing plants and wildlife. The closures, she said, may be an opportunity to take a closer look at nature in our own backyards.

“Of course, I hope people had fun getting to know the critters in their yard,” Duffy said. “The more you know, the more connected you feel and the more you want to know. Maybe it was a good year for noticing the little things.”