Conservation Challenge: Poisoning
In 1962, Rachel Carson wrote her seminal book, “Silent Spring,” which alerted the world to the environmental dangers of DDT. Eventually, the use of the pesticide (dichlorodiphenyltrichloroethane) was banned in the United States and other countries. After nearly 30 years of captive breeding and releases to the wild, the Peregrine Falcon recovered from its brush with extinction due to DDT and was removed from the U.S. Endangered Species List.
Since then, many other substances have been found to have unintended consequences for birds of prey and other wildlife, especially scavengers at the top of the food web. Chief among them are:
- Lead poisoning is the most significant challenge to the recovery of California Condors. Our research and experience shows that lead from spent ammunition is a common source of lead exposure in condors and other wildlife that scavenge on carcasses and gut piles in the field, especially during and following the deer hunting season.
- The Peregrine Fund discovered in 2003 that the veterinary drug diclofenac was responsible for a catastrophic collapse of vulture populations in South Asia in less than a decade. The drug was banned for veterinary use in 2006 by India, Pakistan and Nepal, and Bangladesh took similar action in 2010. Continued use imperils efforts to recover the species affected.
- In Africa, vulture numbers have declined dramatically due to a toxin called Carbofuran or Furadan, a carbamate-based pesticide that is misused by livestock owners and others to poison predators like lions and hyenas that attack domestic animals. Despite efforts to ban it, Furadan is still cheap and available over the counter and, as a consequence, many vulture populations have plummeted in recent years.