Lead from carrion killing off California’s condors
When dairy farmers in California see the white Dodge pickup truck with the brown logo of the US Fish and Wildlife Service on the door, they know it’s time to bring out their dead. The biologists come by every couple of weeks to collect the bodies of stillborn calves and haul them to walk-in freezers strategically positioned around the state. Then, in the dark of night, they drag the corpses into clearings visible at dawn from the heights flown by California condors, a species that has battled back from the brink of extinction but is not yet trusted to feed itself. The massive birds now fly, nest and reproduce reliably outside zoos. But left to plan their own meals, they will swoop down on the carcasses of animals killed by hunters and, in gobbling the carrion feast, ingest chunks of the bullets that scientists now call the most persistent threat to the reestablishment of California condors in the wild: secondhand lead. “The science is irrefutable. There isn’t a shadow of a doubt that lead from ammunition is the leading cause of death and illness in the California condor,” said Judd Hanna, fired by Governor Arnold Schwarzenegger as member of the Fish and Game Commission for promoting a ban on lead ammunition in the condor habitat. Scientists cannot determine precisely how many of the deaths resulted directly from lead, but a recent study indicated 90 percent of condors in Arizona tested positive for lead during this year’s hunting season.
AIDS researchers warn that trial vaccine may worsen HIV risk
South African AIDS researchers have begun warning hundreds of volunteers that a highly touted experimental vaccine they received in recent months might make them more, not less, likely to contract HIV in the midst of one of the world’s most rampant epidemics. The move stems from the discovery last month that an AIDS vaccine developed by Merck & Co. might have led to more infections than it averted among study subjects in the USs and other countries. Among those who received at least two doses of the vaccine, 19 contracted HIV, compared with 11 of those given placebos. Researchers shut down the trial on the grounds that the vaccine was proving ineffective, but the surge in infection among vaccinated volunteers prompted intense scientific debate and anxiety among researchers. The failure of the Merck vaccine is the latest in a series of disappointing results for research projects aimed at curbing AIDS. Researchers in Soweto, Cape Town, Durban and two other sites began contacting South Africa’s 801 trial participants on Tuesday, mainly by cellphone text message. The goal is to tell each one individually whether they had received a placebo or the vaccine, a process called “unblinding” the trial. Researchers are telling the roughly half who received the vaccine that it might have increased their risk of contracting HIV. (LAT-WP)
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