| The Magazine of the CALIFORNIA ACADEMY OF SCIENCES |
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Feature Mirrors, Magic...and Murres Laura Helmuth Biologist Mike Parker is a magician. He needs no smoke, but he does use mirrors–mirrors, decoys, and loudspeakers. His audience is a seabird called the common murre, and his trick is to lure the birds back to a breeding site they abandoned after an oil spill more than a decade ago. Murres breed in loud, crowded colonies on narrow cliff ledges. Parker and his colleagues from the U.S. Fish and Wildlife Service's San Francisco Bay National Wildlife Refuge Complex want to convince the birds that the abandoned site, Devil's Slide Rock, 15 miles south of San Francisco, is the hot, hip place to breed. The decoys, mirrors, and amplified recordings of calls are supposed to assure murres still looking for a place to settle down that everyone is doing it here. It isn't easy. Devil's Slide Rock juts 70 feet out of the Pacific Ocean. Waves crash halfway up the island; its sides are steep and encrusted with barnacles, and the top–where the team of biologists arranges the wood and plastic mock murres in their best approximation of a thriving colony–is slick and smelly from years of accumulated guano. "They said it couldn't be done," says Harry Carter, from the U.S. Geological Survey, who consults on the restoration project. When other seabird biologists heard about the proposed plan four years ago, "they said it was too dangerous. They said it would be impossible to work on that rock." In early 1998, it proved to be almost impossible. El Niño storms battered the rock all winter while the biologists paced, impatient to deploy the decoys before the breeding season began. "We've been on call for months," says Dave Nothhelfer. His boots are shredded and his ripped pants are duct-taped together at the knees after weeks in the field. "They just don't make gear tough enough for field work," he says. Finally, in early March, the weather broke from stormy to gray and drizzly, and the Team Murre biologists made their first landing of the season on Devil's Slide Rock. On the first day of spring, the sea is again calm enough to boat out to the island, and I accompany the biologists as they set out to complete the staged murre colony. Onboard the 40-foot fishing boat Queen of Hearts, Team Murre dons bright orange survival jackets and looks out to take the measure of the sea. Except for Emilie Craig, who has only been on the team for three weeks, everyone has fallen into the ocean at least once. Craig smiles a bit uneasily. During the first expedition of the season, refuge biologist Jen Boyce slipped in up to her waist when she leapt onto the island. Thanks to the rain, the slippery rock "was like being in a sea of guano," Boyce says. "My mom asks me why I'm doing this." The boat's route from Half Moon Bay harbor north to Devil's Slide Rock veers around an infamous surf spot called "Maverick's," where 10-to-20 foot waves swell up routinely, and 30-foot waves sometimes break. The power of nature is palpable here. On the mainland, about 1,000 feet to the east, Devil's Slide has slid again. The steep hillside above the highway cuts off traffic every few years, and workers are once more trucking away the season's debris. Below the highway is the scar of a railroad track that connected Half Moon Bay to San Francisco until its foundation slid into the ocean in 1925. Once the Queen of Hearts nears Devil's Slide Rock, two biologists jump ship into a rubber Zodiac boat. Propelled by an outboard motor, the 14-foot Zodiac is maneuverable enough and sufficiently shallow-drafted to butt up against the island. While Carter steadies the boat, the others hurl helmets, ropes, cargo nets, and bags of decoys inside and then climb in on top of the mountain of gear. Catching a swell, Carter surfs the Zodiac straight at the towering cliff face of Devil's Slide Rock. The harrowing first step ashore is a narrow ledge lined with gooseneck barnacles and mussels some four feet above sea level, except the sea isn't level. On each approach, crew members must leap, one at a time, from the Zodiac, as it rides the cresting waves, onto the ledge and cling there as the waves break over their boots. They quickly adjust their helmets, harness themselves into rock climbing ropes and ascend the slick sides to make room for the next jumper. Some 350 adult murre decoys stand at attention atop the island. Though they do not move, it sounds as though they are calling–and loudly–as piped-in murre music carries across the cove. Parker recorded a murre colony on the Farallon Islands, west of San Francisco, and now loudspeakers blare the colony's chorus perpetually. Solar panels fuel marine rechargeable batteries to keep up the din. Murres make squawky, croaky calls. When they're really excited, it sounds like they're playing the kazoo. In between the solar panels and decoys, twelve mirrors are propped up so that arriving murres will see their reflected movements. Otherwise, the colony would look a bit unconvincing, even to a murre. Today, the biologists are adding wooden eggs and eight-inch-tall chick decoys to the colony. The black-and-white chicks are covered with felt, so they have that just-born baby bird look. The scientists remove the whitened decoys at the end of each breeding season to scrape off all the guano. The decoys soak in a bath of Biz and water to loosen the muck, and then the biologists hand-scrub each one. "We have to re-fuzz the babies every year," says Boyce. Fortunately, classrooms full of eager volunteers help with another annual task: re-painting the mock murres. Students attending schools from Pacifica south to Half Moon Bay paint the decoys in after-school workshops. During the breeding season, the students track the murres' success. "We send them regular updates on the number of birds on the rocks," says Boyce. Murre populations have plummeted in many of their historic nesting areas, but the birds are wide ranging. In the Pacific Ocean, they breed from Big Sur north to Alaska and along the Asian coast to Japan. In the Atlantic, they nest from Maine through Canada and south through Scandinavia, Britain (where they're called guillemots), France, and Portugal. Throughout their range, oil pollution and gill netting have killed birds or forced them from their historic breeding grounds. Devil's Slide Rock is close enough to a surviving colony in the Farallon Islands, however, that murres find the decoy colony and can be persuaded to homestead there again. Conditions in a real, thriving murre colony would send a claustrophobe into fits. Hundreds of birds crowd onto a cliff face. The foot-and-a-half-tall birds, with black backs, black heads, and white bellies, greet their lifelong mates each spring when they return to their nesting spot to court and breed. The male throws his head back, pointing his bill up in the air. Both sexes bow to each other, stroke each other's bills, and preen each other. They build no nests, but lay their single egg on a bare patch of ledge. Just three weeks after hatching, the half-grown chick flaps down into the ocean and learns to feed. The father shepherds the chick around in the water for at least three weeks, feeding it until it learns to fly. Father and child squawk back and forth across the waves to maintain contact. Only in the common murre, as far as bird biologists know, does the father exclusively teach and guard the chick after it leaves the nest. The common murre is the latest in a string of "clients" for whom National Audubon Society biologist Steve Kress has helped find new homes. He invented the decoy-loudspeaker-mirror method, called "social attraction," in the 1970s, and he consults on the murre restoration effort. Kress first enticed puffins and terns to rocky islands off the coast of Maine. The birds had been driven away at the turn of the century by plume hunters, who sold the billowy breeding plumage to hat makers. The murres' deadliest enemy isn't plume hunters, but oil. Devil's Slide Rock hosted a thriving colony of some 2,900 common murres until 1986, when an Apex Oil Company barge spilled 25,000 gallons of oil, coating beaches from Monterey to Point Reyes. In one of California's worst spills, at least 6,300 common murres were killed. Those who survived abandoned Devil's Slide Rock, and for the next ten years hardly any murres ventured to the island. The birds are particular about where they nest, and they have long memories, preferring to nest in their natal cliffs. Apex was charged under the Clean Water Act and the National Marine Sanctuaries Act with destruction of national resources and, after a bitter, five-year court battle, paid $6.4 million. A large slice of that money now funds the murre restoration project, overseen by the U.S. Fish and Wildlife Service. "This is exactly where the money should be spent," says Carter, circling Devil's Slide Rock in the Zodiac. The immediate goal is to reestablish a breeding colony equaling the size of the colony prior to the oil spill. The larger goal is to protect the species from future ecological disasters. The more breeding colonies spread out along the coast, the better the chances that some will escape the next spill. Murre populations recover slowly; the birds do not breed until they are four to six years old, and then each pair produces just one egg per season. Back in 1908, for example, egg hunters disturbed a breeding colony on nearby San Pedro Rock. No murres have bred there since. Stocked with decoys and serenaded in stereo, the mock murre colony at Devil's Slide mimicked a real one so well that several live, randy murres soon decided to join the crowd. By 1997, the second year of the repopulation effort, nine breeding pairs made Devil's Slide Rock their home. Some of the murres, who can live more than 20 years, may have been members of the original colony wiped out by the oil spill. Seeing their native breeding grounds apparently teeming with life, they have decided to give the jagged pinnacle another chance. In 1998, despite El Niño, a record number of murres settled on the rocks. Just one day after setting out the first batch of decoys, the biologists (muscles still aching from the previous day's climb) counted 30 birds. By the end of the breeding season, up to 80 had joined the colony. Fifteen breeding pairs laid eggs, nine of which hatched. In July, six chicks fledged, leaping into the ocean to join their fathers. While the others finish arranging the decoy colony this March day, in preparation for the breeding birds to come, Carter zips the Zodiac around the base of the island, watching the birds fly around the cove and swim near Devil's Slide Rock. "This feels like a colony," says Carter, who has studied murres for 20 years. The biologists have decided that since the Devil's Slide Rock colony is attracting birds so successfully, they should try to repopulate San Pedro Rock across the cove, as well. Once the rock climbers have nestled the last decoy chicks and eggs into place on Devil's Slide Rock, Carter picks the biologists up and ferries them over. Boyce leaps into the Zodiac laughing. She says she still loves the work, even after three seasons of climbing around on the guano-frosted rock. "Maybe after the fourth season I'll get tired of it," she says over the growl of the outboard engine. "Probably not." They haul in more supplies from the patient, bobbing Queen of Hearts. Carter steers the Zodiac up to San Pedro Rock between crashing waves, and Nothhelfer heaves solar panels, decoys, and 50-pound batteries to Parker, already perched precariously on the rocks. After the supplies and scientists have been delivered, the biologists painstakingly ascend San Pedro Rock and place decoys all around. They anchor the batteries and position the loudspeakers, preparing to cast another spell. Laura Helmuth is a freelance writer in Santa Cruz, California. |
Winter 1999
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