Baited with peanuts, the trap is stunningly low-tech.
A wire mesh basket is propped on a stick tied to a string. A researcher in the brush tosses peanuts and makes pssht! bird noises. Then, when an island scrub jay hops under the basket, he lowers the boom and, minutes later, announces over a crackling two-way radio: "We have bird in hand!"
What sounds like a scheme concocted by Wile E. Coyote is part of an elaborate effort to preserve the island scrub jay, a bird that lives only on rugged Santa Cruz Island. It is the only bird in North America that lives exclusively on a single island.
The rare jay is not officially endangered but could be in peril: Biologists working in Channel Islands National Park worry that it's easy pickings for the West Nile virus, which could swiftly wipe out the species once infected mosquitoes or birds cross the Santa Barbara Channel.
"It's imprudent to think it's not going to happen," said Scott Morrison, director of conservation science for the Nature Conservancy in California. "It's just a matter of time."
Working on and off for more than a year, a crew has been laboriously trapping jays one by one and inoculating them with a vaccine produced — initially for condors — by the Centers for Disease Control. By next spring, the crew on Santa Cruz will have given the needle to about 250 birds — enough, they hope, to form a disease-resistant core if West Nile takes out all the rest.
Coordinated by the Nature Conservancy, which owns 76% of Santa Cruz, the complex effort draws on scientists from the UC Davis Wildlife Health Center, the Smithsonian Institution and Colorado State University. Just figuring out the size of the jay population was no simple task: For a week in the fall and a week in the spring, a helicopter flew keen-eyed observers with laser range finders to some 300 locations to look and listen for jays.
"Santa Cruz is crazy rugged," said Scott Sillett, a Smithsonian biologist. "If you were to hike to all those spots, you'd blow out several sets of knees."
Using statistical models, researchers figure there are fewer than 3,000 island scrub jays on the 96-square-mile island. They don't know whether the species is declining.
But a plummeting population would be an environmental tragedy, Sillett said: "We'd lose North America's only endemic island bird. On all the continent's thousands of islands, there's just one species confined to a single island — and this is it."
Birders from around the U.S. come to the island, hoping to glimpse its native jay.
The jay also is thought to be a key player in the comeback of Santa Cruz, an island degraded over many decades by thousands of grazing sheep and marauding feral pigs. With the livestock now gone, new stands of scrub oak are sprouting up across barren hillsides — largely because each jay finds and buries thousands of acorns a year.
"They're almost maniacal," Sillett said. "Losing them would have a dramatic effect on the ability of the island to return."
The island scrub jay is a cousin of the Western scrub jay, a fixture in Southern California backyards and campgrounds. The Santa Cruz version is bigger — the reasons for "island gigantism" are unknown — and a more brilliant blue. Like crows, island scrub jays are corvids — a family of birds so intelligent that one expert has dubbed them "feathered apes."
"They have a fantastic memory," said Mario Pesendorfer, a doctoral candidate at the University of Nebraska, who is working on the island. "They may even be able to plan for the future."
When they pick up acorns, they rattle them around, listening for weevil damage. When they bury them, it's always bottoms up — the perfect position, it turns out, for growing trees. When they see a peanut, they sometimes know it's just jay bait.
Pesendorfer lives in a rustic camp, with Colorado State graduate student Katie Langin and three workers who help them track birds over the island's steep ridges. At the crack of dawn, they set out in search of island scrub jays — to weigh them, band them, look them over for parasites, draw blood that will be checked for avian malaria. They take an array of measurements, from the length of the jays' tail feathers to the curvature of their beaks.
In addition to pursuing their own research on jays, the young biologists vaccinate them. The program's cost is about $100,000 a year, with about half coming from private sources and the rest from the National Park Service and the U.S. Fish and Wildlife Service.
One morning, outside the tiny cabins the group calls home for three months at a time, Langin cradled a captured bird that seemed to have descended into Zen-like tranquility. Even as she pricked its breast with a needle, it barely moved.
"Some species can be so wimpy," said Langin, who is writing her thesis on the jays' adaptability. "These guys don't mind at all."
It's tedious and painstaking — work that only biologists could love. Sometimes they follow a single bird for hours, mapping its favorite trees and the endless array of places it caches acorns. Trapping a jay can take just a couple of minutes — but many of the birds are unmoved by peanuts and seem to skeptically size up the researchers intent on saving their species.
On a promontory above the camp, jays — many of them already banded and vaccinated — swooped in to check out a trap.
"That's the neighbor from across the canyon," Pesendorfer said, "and that's his female. And here comes Joe Biden!"
The scientists' political nicknames for the birds are a rare reminder that the island just 25 miles offshore is part of modern-day America.
With the last of 5,000 pigs shot by contract hunters in 2006, the landscape is starting to again fill with plants — coyote brush, Mariposa lilies, island buckwheat — that have been native to it for thousands of years. Bald eagles soar overhead and island foxes saunter through the brush.
So far, testing has shown no sign of West Nile. But the virus spreads quickly. It emerged in New York City in 1999, and by 2003 was infecting both people and birds in California.
So far, it's killed nearly 100 Californians and tens of thousands of birds, including half of the yellow-billed magpies that are the signature bird of the Central Valley. Corvids are particularly vulnerable.
Whether island scrub jays will be the next victims is an open question. Though the vaccine they're receiving has produced encouraging test results, nobody knows how effective it will be or how long it will last.
"We're hoping they won't need booster shots," said the Nature Conservancy's Morrison. "You can catch them once and give them a shot, but it's not so easy the second time around."