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.
In 2008, The Peregrine Fund organized a landmark conference, “Ingestion of Lead from Spent Ammunition: Implications for Wildlife and Humans” in Boise, Idaho. It drew 150 professionals from the fields of human health, wildlife health, management and conservation, outdoor sports and hunting, and public policy to hear research, discuss solutions and share expertise. The conference proceedings are available at no charge online or in book form by ordering here.
The World Center for Birds of Prey is home to the world’s largest flock of captive California Condors. Chicks are hatched and raised by their parents, then transferred to our release facility at Vermilion Cliffs in northern Arizona. When released to the wild, the birds each have a wing tag that identifies them and allows the field staff to track their movements as the birds forage in Arizona and southern Utah.
Each year since 2000, The Peregrine Fund has trapped almost every condor in the Arizona flock and tested each one for lead exposure. If they have ingested fragments of lead in carcasses or gut piles from game animals shot with lead ammunition, the condors become sick or die unless they are treated to remove the lead from their system.
The Peregrine Fund has 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.
In 2018 The Peregrine Fund, along with the Oregon Zoo and the Institute for Wildlife Studies, founded the North American Non-lead Partnership to expand the coalition of hunters, anglers and other conservationists dedicated to improving ecosystem and wildlife health by choosing non-lead options.
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.
The drug is still used to treat livestock in some areas although a safer alternative, Meloxicam, is now available. Vulture populations may be stabilizing, but, tragically, some species already have declined by up to 99 percent, making extinction a continued threat to these ecologically and culturally important birds.
Species affected include:
Diclofenac is an anti-inflammatory drug used to treat ailing livestock. Even a trace of diclofenac in a carcass is enough to cause vultures to die slowly and painfully of renal failure. Just one cow carcass can poison many vultures, which eat in social groups. Not only has diclofenac brought the birds to the brink of extinction, but the effect of the vulture population decline on people is becoming evident, too. The drop has caused a burgeoning population of feral dogs, rats, and other animals more likely to come into contact with humans and spread rabies and other diseases.
Vultures fill a vital ecological niche as nature’s clean-up crew. These remarkable birds can pick a carcass clean long before it has time to contaminate land and water resources. The Peregrine Fund was the first conservation organization to set up “vulture restaurants” in South Asia, where diclofenac-free carcasses were set out for vultures to eat.
See the Asia-Pacific Program for more information on our work with Asian vultures.
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 their domestic animals. Despite efforts to ban it, Furadan is still cheap and available over the counter.
U.S. manufacturers have halted sales of Furadan to Kenya, where large die-offs have occurred, but the devastating effects continue to be seen on all scavenging animals. A single Furadan-laced carcass kills lions, hyenas, jackals, and scavenging birds including vultures, Marabou Storks, Bateleurs, and Tawny Eagles.
Vulture species affected include:
These three species have declined at such an alarming rate in one of Africa’s most significant wildlife reserves that they are threatened with extinction. A 2010 study by The Peregrine Fund, National Museums of Kenya, and Princeton University found that vulture populations around the Masai Mara National Reserve have dropped up to 60 percent in three decades.
The Peregrine Fund supports ongoing studies and education efforts in Kenya and elsewhere in Africa. See Africa Program for more information about our work with vultures.
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.
The Peregrine Falcon was one of the species hit especially hard by the widespread use of DDT in the 1950s and ’60s. Subsequent research showed that DDT and its derivatives broke down very slowly in the environment, accumulated in the food chain (becoming more concentrated with each link), and reached such high levels in top predators, such as the Peregrine Falcon, that it interfered with their calcium metabolism and caused eggshell thinning in birds. By 1972, when DDT was banned, Peregrine Falcons were gone from the eastern half of the United States.
The Peregrine Fund was founded in 1970 to bring the falcon back from the brink of extinction through captive breeding and release to the wild. More information about our history is available here.
Birds of prey are excellent indicators of environmental health. Their problems are an early warning system that there may be effects on people, too. Recent studies have shown that childhood exposure to DDT and its derivatives from 1945 through the 1950s is linked to a five-fold increased risk of breast cancer in women who are now in their 50s.
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.
From the clear-cutting of rainforests in the Philippines to the plowing up of native grasslands in Mexico, birds of prey are losing their homelands at an alarming rate. The Peregrine Fund is actively involved around the world in efforts to protect and restore the landscapes that endangered birds of prey require for food and shelter.
Birds of prey are an effective indicator of environmental degradation. They are near the top of a delicate food chain that works sustainably only if all the pieces and parts are in their proper place. Without a reliable food source, birds of prey cannot live and raise young in the landscapes to which they belong.
In Madagascar, in partnership with local communities, we are developing protected areas to safeguard habitat for many endangered species, including:
See Madagascar Project for more information about our work in this island nation, home to some of rarest animals on Earth.
Habitat protection is sure to be one of the most confounding problems facing the fast-growing human population in the 21st century. The Peregrine Fund’s experience and expertise in working cooperatively with landowners can contribute to solving problems, finding solutions, and leading the way to a future that preserves the world’s incredible diversity of birds of prey for future generations.
Birds of prey are shot on sight in many parts of the world, mostly as a result of misunderstanding and fear. People often believe birds of prey are a threat to their domestic animals, when in fact they can be beneficial. Occasionally, a radio or satellite transmitter has led field staff to homes with an endangered bird in the stewpot, especially in areas where poverty and unsustainable population growth create conflict.
Shooting affects all birds of prey but is especially harmful when it further reduces the numbers of rare and endangered species. Some of these vulnerable species include:
Our experience has shown that intensive education efforts can build pride and reduce persecution of endangered birds of prey.
In Panama, our staff visited classrooms and villages in areas close to Harpy Eagle habitat to explain the benefits of this forest raptor, launched a festival to celebrate the Harpy Eagle, and helped make it Panama’s national bird. In Dominican Republic, we partnered with the Hispanola Ornithological Society to develop an entertaining play that was performed in rural areas to explain that the Ridgway’s Hawk is a helpful predator of snakes and rodents, not chickens. In the Philippines, we support outreach and education efforts by the Philippine Eagle Foundation.
Such measures with local partners are crucial to preventing the shooting of birds of prey.
The Gyrfalcon and its main prey, the 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 has begun exploring how climate change might affect birds of prey like the Gyrfalcon and what steps can be taken to confront its effects.
In early 2011, we organized an international conference, Gyrfalcons and Ptarmigan in a Changing World, in Boise, Idaho. More than 120 scientists, scholars, wildlife managers, and other conservationists from around the world attended to share findings, learn from one another, and determine what knowledge gaps remain. The presentations have been published in book form and also made available online.
Ian Newton, a renowned ornithologist who serves on our board of directors, summed up the results of the conference this way:
“Sea ice is shrinking, spring is earlier, vegetation is clearly responding, tree lines are rising, willow patches are expanding but not everywhere. Key species are going to lose habitat.”
Newton urged researchers to go beyond monitoring the species to improving a broader understanding of a highly complex problem.
Future plans include: