Every April, thousands of elegant terns migrating from Central and South America nest in the sands of the Bolsa Chica Ecological Reserve, one of the last remaining protected coastal wetlands in Southern California.
This year, however, their refuge was no sanctuary. On May 13, a drone crash-landed on their nesting ground, scaring off about 2,500 of the terns. Left behind were about 1,500 eggs, none of which were viable after they were abandoned.
“In my 20 years of working with wildlife and in the field, I have never seen such devastation,” said Melissa Loebl, an environmental scientist and manager of the Bolsa Chica Ecological Reserve, which encompasses more than 1,300 acres of mud flats, saltwater and freshwater marshes, dunes and other habitats in Huntington Beach, Calif.
“My gut is wrenching,” Ms. Loebl said. “It’s awful to see.”
Nicholas Molsberry, an officer with the California Department of Fish and Wildlife, said no one had come to claim the drone in the three weeks since it crashed into the colony.
Officer Molsberry said he was seeking a search warrant to allow him to review the contents of the drone’s memory card, which he hopes will allow him to identify the operator and the flight path the drone took that day.
If he can find the person, he said, he will seek misdemeanor criminal charges relating to the needless destruction of eggs or nests, the harassment of wildlife and the use of a drone in a closed ecological reserve.
The elegant tern, a sleek seabird with a pointed orange bill, is among 800 species that rely on the reserve as a critical habitat, Ms. Loebl said. Although the elegant tern is not considered threatened or endangered, a number of other birds in the reserve are, including the California least tern and the Ridgway’s rail, Ms. Loebl said.
She said it was not surprising that the elegant terns had abandoned their eggs when the drone crashed on the sand where they were nesting.
“They were responding to a threat,” Ms. Loebl said. “That drone, to them, was a huge predator. It came crashing down and absolutely terrified them.”
Despite being a protected sanctuary, the reserve has frequently been disturbed by bikes, dogs and drones, another one of which crash-landed on the reserve on May 11, according to Ms. Loebl and Officer Molsberry. The crash on May 13 was previously reported by The Orange County Register.
“It’s always been a hot spot for these violations,” Officer Molsberry said. “I really wish we had more officers to patrol.”
Ms. Loebl said drones were already prohibited in the reserve under California rules, but she hopes the Federal Aviation Administration will issue a federal rule against operating drones in the area.
“I am really hopeful we are going to make positive change as a result of something so horrible,” she said.
Michael H. Horn, a professor emeritus of biology at California State University, Fullerton, said that although the loss of 1,500 eggs might not threaten the long-term health of the elegant tern, which has a worldwide population of about 100,000 to 150,000, the drone crash was still troubling.
He said the reserve was one of four important nesting sites for the elegant tern. Three are in Southern California, and one is in the Gulf of California in Mexico, he said. Though the nesting areas are typically threatened by coyotes, peregrine falcons and other predators, drones should not be among the hazards, he said.
“We need more protection,” he said, “and I am hoping the attention this is getting is going to help us.”
He said had long worried that the increasing popularity of drones would eventually pose a threat to nesting seabirds.
“I knew it was going to happen,” he said. “I just didn’t know when.”