Back in the Wild, Condors Succumb to Old Nemesis: Lead

spectr17

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Back in the Wild, Condors Succumb to Old Nemesis: Lead


By DEBORAH SCHOCH, L.A. Times Environmental Writer


   Bird G32 fell from the sky one January day, too weak to fly and too wobbly even to stay perched on the branch of a withered tree. As helpless rescuers watched, the 4-year-old female condor took flight one last time and plummeted straight down. Biologists scrambled in pursuit through mountainous terrain near Paso Robles, finding the bird's body warm but its pulse stilled.

   Dead from lead poisoning, the bird was the fourth to die of the same cause in the past year.

   The return of the huge, black-winged birds to the wilds has been hailed as one of America's great environmental success stories. "We're pulling this majestic bird back from the brink of extinction," U.S. Interior Secretary Gale Norton said during her first official trip to California in April, when she released five of the birds in Big Sur.

   However, the reintroduction of captive-bred California condors to their native habitat is being threatened by the same peril--lead from bullets--that scientists believe was largely responsible for driving the birds to the edge of extinction 28 years ago.

   Since 1997, besides the four fatalities, 13 birds have required elaborate drug treatment to remove potentially lethal levels of lead. Condor scientists suspect that the birds, released in remote areas of Arizona and California, fed on carcasses of animals killed by gunfire, swallowing lead pellets or bullet fragments that slowly poisoned them.

    The casualties are casting a pall over one of the most high-profile, sophisticated and costly efforts in U.S. history to prevent a species from vanishing from Earth. An estimated $30 million in government and private money has gone to rehabilitating the species.

    The condor is North America's largest bird, with a wingspan of up to 9 1/2 feet. Its population had dwindled to 22 in 1982 and biologists set out to save the species with an experimental captive breeding program at zoos in Los Angeles and San Diego. After nine years of nursing and fledging newborn birds, biologists released two birds in the Sespe Wilderness in Ventura County and later along the Big Sur coast and in northern Arizona near the Grand Canyon.

    The official June 1 tally showed 128 of the birds in captivity and 56 condors flying free, learning to feed on animal carcasses like their ancestors and facing the same threat of poisoning.

    The danger creates a quandary for the biologists trying to restore the species. How can they save creatures from near-extinction, only to release them back into a world where the same threat awaits them?

    "We always knew the lead was out there," said Patrick T. Redig, professor of raptor medicine and surgery at the University of Minnesota and a member of the scientific team overseeing the program.

    "Now it's like, 'Holy smokes. Here we go. As soon as they get off the free lunch counter, they're into trouble.' "

    In March, scientists on the California Condor Recovery Team called on the federal government to take steps to eliminate lead bullets on some public lands and to encourage the use of lead-free ammunition.

    To date, the team's appeal has not drawn a response from federal officials, including Norton.

    Interior Department spokeswoman Stephanie Hanna said June 5 that Norton hadn't been made aware of the recovery team's appeal. Hanna referred questions to the U.S. Fish and Wildlife Service, which reports to Norton.

    In fact, the team's recommendations remain in the California office of the service where they were first sent in March. Miel Corbett, the service's Southern California liaison, said Wednesday that the recommendations will be analyzed and the conclusions forwarded to Washington.

    In Sacramento, Resources Secretary Mary Nichols' office referred questions to Ron Rempel, deputy director of the Department of Fish and Game.

    "We want to look at whether we have good information, whether we can trace it back to some specific lead in the environment, so that we can really focus on what's causing the problem," said Rempel.

    The condor recovery team found little room for doubt.

    "Available evidence indicates the ultimate source of lead is spent lead-containing ammunition in the form of shotgun pellets and fragments from slugs or rifle bullets," the recovery team stated. It also said lead toxicity appears to have played a major role in the birds' original plight.

    While some scientists have talked of removing birds from the wild, recovery team member Bill Heinrich of the Idaho-based Peregrine Fund says he is optimistic that the program will succeed despite the recent deaths. Heinrich's group oversees the releases in Arizona, where three birds died in rapid succession last year. He and others wonder if the birds fed on a large carcass that teenagers had used for shotgun practice. He believes the deaths were a fluke.

    "I say that with my fingers crossed," Heinrich said.

    Federal officials recognized the lead problem when they removed all condors from the wild in the mid-1980s, said Noel Snyder, a former Fish and Wildlife Service biologist who helped manage the condor program in 1980-86.

    "The major reason given for this was the lead poisoning problem," Snyder said.

    Experts later debated whether to release the captive-bred birds. They decided to do so and to supply the newly released birds with lead-free food, such as stillborn calves. The practice continues. As the condors grow more confident in the wild, they roam more widely and find their own food. Scientists believe that is how they get in trouble.

    In all, more than 40 condors have died since the releases began nine years ago. Some were electrocuted by power lines and others eaten by coyotes and golden eagles. Two drowned in a pond.

    The lead fatalities started showing up in Arizona last year when three birds died of poisoning.

    Three other condors that had been treated for lead poisoning were among five that disappeared in Southern California during 1999 and 2000.

    At least six condors have been found dead of unknown causes in Southern California in the last two years. Condor carcasses are often found days after the birds have died, the causes obscured by predators and decomposition.

    Lead can be more toxic to condors than to eagles and other birds. Some birds swallow feathers, bones and other indigestible items that they later regurgitate in the form of pellets. Any lead fragments swallowed by mistake could be disgorged. But a condor rarely regurgitates pellets. And even a lead sliver the size of the end of a fingernail can poison a bird, causing anemia, mental dullness, seizures and blindness.

    Condors can crave calcium, searching for bone shards in a carcass and possibly swallowing lead by mistake. X-rays of some sick birds have revealed lead fragments or pellets in their digestive systems.

    "There may even be a propensity for these birds
to go after a bullet," said Mike Wallace, recovery team leader and a wildlife biologist at the Zoological Society of San Diego.

    Wallace helped treat W5, a 4-year-old male rushed to the Los Angeles Zoo in 1998 with severe lead poisoning.

    Veterinarians inserted a feeding tube and fitted the bird with a large cone-shaped collar so it would not pull at the tube. They fed it a baby-food-like substance, gram after gram, day after day. They performed chelation, injecting a drug that speeds up the excretion of lead. Four months later, W5 was discharged. The bird was observed for two years in the wild and then vanished.

    Only one of the three launch sites has not seen lead deaths--the remote Ventana wilderness near Big Sur. There, 18 condors remain in an area where hunting is infrequent. The birds are young and still dependent on the lead-free diet supplied by their former keepers. But the Ventana Wilderness Society, which oversees the site, is taking nothing for granted.

    "We're preparing for the worst," said Kelly Sorenson, the society's assistant director. The society plans to build a special facility in case it needs to treat lead-poisoned birds.

    One breakthrough cheering condor keepers is the so-called green bullet developed by the U.S. Army. Instead of lead, the bullet's core is made of tungsten and tin or tungsten and nylon. The Army is using tungsten bullets in its standard-issue M-16A2 rifle. The bullet appears to cause less barrel erosion than lead and is slightly more accurate at 300 to 400 meters, an Army official said. A round costs the Army 31 cents to 33 cents, compared with 20 cents to 21 cents for the equivalent lead bullet.

    Privately, some biologists worry that insisting on banning lead would be a political disaster, angering hunters and alienating politicians. Others refuse to mince words.

    "Before you put animals back in the wild, you have to solve the problems that caused them to die in the first place," Snyder said. "Instead, you are just throwing birds out in the wild to die."
 

grizz

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Four dead from lead don't sound to bad.  When you compare that to thrity six from other causes.
 
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