A Clown Makes a Comeback
SOUTHERN SEA OTTER
Year listed: 1977
Skill: Uses tools (rocks, shellfish) to obtain food
Hundreds of thousands of sea otters once ranged from Baja California to northern Alaska and across the Bering Strait to Russia and Japan. The animal was thought to have been eliminated from the California coast in the early 20th century, despite a 1911 international treaty that protected sea otters from the fur trade. In 1938, biologists made a startling announcement almost like that of the recent ivory-billed woodpecker’s rediscovery: up to several hundred animals were living near Big Sur. With that news, a rocky conservation success story began unfolding.
Over the next four decades, in the absence of hunting pressures, the sea otter population in California climbed to approximately 1,800. But the otters faced new problems, including oil spills and some commercial fishermen who considered the otters competition (they are voracious eaters) and killed them. Commercial gill net fishing, a practice akin to dropping a curtain into the water and capturing almost anything that swims by, killed an estimated 1,000 sea otters between 1973 and 1983.
The otter’s tale provides a lesson in why species protection is so urgent. Plants and animals in a particular region interact with one another in intricate and sometimes unknowable ways; the disappearance of a species can set off a cascade of problems. Take the sea otter in Alaska. Research biologist Jim Estes of the USGS Biological Resources Division suspects that overharvesting of whales in the Aleutian Islands in the 1990s prompted orcas, which eat other whales, to venture closer to shore and prey on sea lions, harbor seals and sea otters. As sea otters dwindled, one of their key foods, sea urchins, boomed. Sea urchins graze on kelp, so kelp forests declined. Without the kelp, crabs, clams, sea stars and many fish species suffered. In California, the decline of sea otters due to hunting and lost habitat had a similar outcome.
The southern sea otter of central California has been helped by the ESA and other laws, including 1980s regulations that moved gill net fishing farther offshore. In the late 1980s, a small otter population was relocated to an island off the coast to ensure a separate, distinct colony as a hedge against a calamitous oil spill or disease epidemic. Today, there are more than 2,500 California sea otters between HalfMoon Bay and Santa Barbara, and the population appears stable. Sea urchins there are returning to normal, and kelp forests are thriving.
Who’s Your Mommy?
Population low point: 21 wild birds in 1941
Surrogate parents: Puppets, costumed people, ultralight planes
One of the most audacious endangered species recovery efforts starts at the USGSPatuxent WildlifeResearchCenter in Maryland, between Baltimore and Washington, D.C. There, researchers breed whooping cranes and prepare them for life in the wild. That might sound simple, but the project uses special effects worthy of George Lucas. Even before a bird hatches, researchers subject the egg to recordings of a roaring motor, to accustom a fetal bird to the sound of its foster parent— an ultralight aircraft. Once the birds hatch, they’re fed by crane puppets, and the people working with the chicks cover themselves in shapeless white sacks to prevent the birds from growing attached to humans. As the baby whoopers grow, they are taught to follow an ultralight equipped with a puppet crane head while a costumed pilot drives the plane in circles on the ground.
When the cranes are ready for the next step, at about 6 weeks of age, biologists ship them by private jet to the Necedah Wildlife Refuge in Wisconsin. There, the chicks learn to fly along after their aircraft parents. When it’s time to migrate, the young cranes follow the ultralight to their wintering home, in Chassahowitzka National Wildlife Refuge in Florida (along the way, the plane stops at different private and public properties to allow the birds to eat and rest). “We show them the way once,” says Heather Ray, who used to work for the group that runs the crane project, Operation Migration. After that, she insists, despite their odd upbringing, “these are wild birds.”