Human changes in land use disrupt the delicate food webs and reproductive cycles that support many species of birds of prey. The world’s rainforests support an amazing array of bird of prey species but this critical habitat is rapidly being cut down or burned to make way for crops, livestock, and development. In other regions, birds like Aplomado Falcons need wide-open grasslands and African Fish Eagles need clean water. Conservation of native habitat is a serious issue that the ever-expanding human population must resolve if birds of prey are to survive.
Lead poisoning remains a 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, which scavenge on carcasses and gut piles in the field during the hunting season. We have partnered with the Arizona Game and Fish Department on an awareness program that has resulted in hunters voluntarily switching to non-lead ammunition in condor country. A similar effort is under way in Utah after condors expanded their foraging range there during the hunting season. Each year, dozens of condors are captured, tested, and, if necessary, treated for lead poisoning, a threat that far exceeds all other causes of death for California Condors.
In Africa, we are assisting efforts to stem the misuse of the pesticide Furadan to kill lions and other large animals preying on livestock. Vultures and other scavengers also are poisoned when they feed on the chemical-laced carcasses, causing large-scale die-offs. U.S. manufacturers have halted sales of Furadan to Kenya, the site of mass vulture deaths, but vulture populations there and elsewhere in Africa remain threatened by poisoning.
The Peregrine Fund discovered in 2003 that the veterinary use of the drug diclofenac had caused 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. Although the drug is still used illegally to treat livestock in some areas, it appears that vulture populations may be stabilizing. Tragically, some species already have declined by up to 99 percent, making extinction a continued threat to these ecologically and culturally important birds. Restoration projects are under way but releases of captive-bred birds to the wild are impractical while diclofenac exists in their food supply.
Birds of prey are shot on sight in many parts of the world, mostly as a result of misunderstanding and fear. Many people believe raptors like the rare Ridgway’s Hawk are a threat to their livestock, when in fact they are not. In a few cases, a bird’s transmitter has led field staff to homes with an endangered Harpy Eagle or Philippine Eagle in the stewpot. Our experience has shown that intensive education efforts can build pride and reduce persecution of endangered birds of prey.
The Gyrfalcon and its main prey, ptarmigan, are well-suited to life in the harsh conditions of the Arctic. Like the polar bear, however, the Gyrfalcon and other birds of prey are likely to experience profound life-cycle changes as the climate warms. The Peregrine Fund recently has begun exploring how climate change might affect birds of prey like the Gyrfalcon and what steps could be taken to confront its effects.
The Peregrine Falcon was one of the species hit especially hard by the widespread use of DDT in the 1950s and ’60s. By 1972, when DDT was banned, Peregrine Falcons were gone from the eastern half of the United States. In some parts of the world, use of DDT is once again being proposed to aid in control of malaria, which is carried by insects. Careful indoor use of DDT may be acceptable, but the lessons learned from a half-century ago need to be remembered today.