Where have all the least terns gone?
Scanning the white sand at Ormond Beach, where the endangered shorebirds traditionally nest in abundance, Al Sanders thinks he knows.
The local Sierra Club point man suspects they've been driven from their breeding grounds by motorized paragliders that have taken to the skies above the Oxnard preserve, tucked into one of Southern California's largest seaside wetlands.
Once home to hundreds of California least terns and their offspring, the sand dune habitat this season has played host to fewer than 30 nesting pairs, and only 10 fledglings have been observed this season at the protected shoreline between Point Mugu and Port Hueneme, according to a state monitor.
After years of working to build the population, years of shooing away wayward dogs and off-road vehicles, Sanders said the sparrow-sized, black-hooded birds face a new threat. This time, it comes from above.
"The birds should be flying all around us here, but they've been driven away," said Sanders, surveying the beach where authorities say they discovered abandoned nests and unhatched eggs. Wildlife monitors also report a decline in nesting by the Western snowy plover, a threatened species.
"The birds go berserk when these things come around," Sanders said. "They'll actually rise up collectively and mob one of these paragliders; it looks just like a giant predator to them."
Ultralight pilots, who in the last year have begun flying regularly at Ormond Beach, dispute those claims.
They say they've taken care to avoid the nesting area. And they say they are working with state and federal wildlife officials to map new flight paths to steer clear of the most sensitive sites.
"They don't seem to have any bother with us," said pilot Bob Armond, who owns a flight store in Newbury Park and is a frequent flier at Ormond Beach.
"The true issue is this: This is an area the bird-watchers enjoy, and we are probably disturbing their peace and quiet," he said. "They are just using this as an excuse to get rid of us."
It is the latest conflict over the terns at Ormond Beach, where wildlife officials, conservation groups and volunteers have scrambled to keep the flock flourishing.
Once numbering in the thousands, with nests from San Francisco to San Diego, the California least tern population dwindled to about 300 pairs by the early 1970s as coastal development and human intrusion took their toll. Although still highly vulnerable, the shorebird has made a comeback as preservation efforts boosted their numbers statewide to 6,688 in 2003.
Ormond Beach has been at the forefront, with wildlife officials and local environmental groups teaming to turn a mile-long stretch of white sand into a least tern haven. With no-trespassing signs and volunteer patrols, the beach has gone from supporting a handful of breeding pairs decades ago to nearly 100 pairs by the end of the 1990s.
Now many of the volunteers are urging authorities to intervene as they launch a campaign to ground the ultralights.
State and federal wildlife officials say they have not drawn a definitive connection between the arrival of ultralight aircraft and the departure of the least terns.
But Morgan Wehtje, senior environmental scientist for the California Department of Fish and Game, said she strongly suspects that the aircraft flushed the terns from their nests, contributing to the poor breeding season, which runs from about mid-May to about mid-September.
"It's not solely the aerial acrobats who are out there -- they're just sort of the straw that broke the camel's back," said Wehtje, noting that predators and human intrusion also continue to plague Ormond's tern colony.
Although enforcement action remains an option, Wehtje said she also understands that the ultralights are drawn to Ormond by the same things that draw the terns each summer -- a wide open, unpopulated coastline.
That's why she and other wildlife officials have been working in recent weeks to craft a compromise that would keep the fliers away from the breeding grounds but still allow them to use the beach.
"If we get a definite flight path, if we can really hammer home the idea that they cannot fly over that part of the beach, I think they can coexist," Wehtje said.
But she also knows that coexistence only works to a point. In other areas, as off-road vehicle owners have discovered sand dunes or wilderness trails, word has spread quickly. And that has brought degradation to environmentally sensitive sites.
"While I believe this current population of powered paragliders and ultralights can be educated," Wehtje said, "I worry about what happens if Ormond becomes known as a place for people to fly."