How The Peregrine Fund is helping

In the mid-1900s, the pesticide DDT was having a devastating effect on many bird species and other wildlife across North America. The Peregrine Falcon was no exception. By the 1960s, Peregrine Falcons were gone from the eastern United States and large portions of the western states due to the effects of this pesticide.

At the time, DDT was being sprayed in agricultural fields, marshes, and other landscapes as a means to control insect infestations. When small birds ate insects contaminated by this pesticide, some of this chemical remained in their bodies. The more contaminated insects they ate, the more they themselves became contaminated. When Peregrine Falcons, in turn, ate these small birds, DDT accumulated in the falcons’ systems as well, but at an even higher rate. This affected the female falcons’ ability to lay healthy eggs. Their eggs lacked calcium, which meant they were thin-shelled and weak. They all broke before hatching, usually when the parents sat on them to keep them warm during incubation. When an eggshell cracks or is broken, the young bird developing inside cannot survive.

Without young falcons being born, the population was in trouble. In 1972, the U.S. Environmental Protection Agency banned the use of DDT, which made recovery of the species possible.

The Peregrine Fund, which was founded in 1970 to save the Peregrine Falcon, pioneered many techniques for successfully breeding the birds in captivity and releasing them into the wild. Special chambers were built to house breeding pairs. Here, the adults received good care and were given healthy food and vitamins, which helped them produce healthy young. Though many people didn’t think it could be done, The Peregrine Fund and other organizations worked together to raise thousands of Peregrine Falcons in captivity.

About a month after hatching, young bird were ready to be released. Biologists worked hard, climbing cliffs and constructing release sites, to place young falcons into the wild. Through captive breeding and release, these falcons were restored to their historic range throughout the United States. When all was said and done, more than 4,000 young birds had been released. All that hard work paid off. In 1999, the Peregrine Falcon was removed from the U.S. Endangered Species List! Today, it is still one of the most successfully recovered endangered species ever.

Where they live

From Morocco to Malaysia, Greenland to Greece, Australia to Argentina, and India to Iraq, Peregrine Falcons live and breed on every continent in the world except Antarctica. They are strong, efficient flyers and skilled at catching a variety of prey from small songbirds to large ducks. This versatility allows them to live in almost any type of climate and habitat – and they do!

Deserts, seashores, mangroves, wetlands, tundra, grasslands, dry forests, scrubland, and craggy mountains are places one might find a Peregrine Falcon. The most common factor among these different locations is the presence of good nesting habitat. These falcons like to nest in high cliffs, but in cities, Peregrine Falcons use tall buildings or bridges instead. In the spring, a webcam monitors the daily life of a falcon family nesting on the ledge of a tall building in downtown Boise, Idaho.

What they do

Among the most impressive birds to watch hunt, Peregrine Falcons are known for their high speeds, impressive aerial acrobatics, and unmistakable grace. But Peregrine Falcons not only fly fast, some populations fly incredibly long distances, too. In the northern part of their range, Peregrine Falcons are migratory, which means they travel from their breeding grounds to non-breeding grounds and back every year. Some of these individuals travel from the Arctic nearly to Antarctica, making a yearly round trip journey of more than 20,000 miles. That would be like crossing the entire United States seven times in one year!

Peregrine Falcons that live closer to the equator tend not to migrate. This makes sense if you think about one definition of migration: the seasonal movement from one area to another for the purpose of finding food or to reproduce, usually triggered by a change in the weather. Since temperatures along the equator are not as extreme as in the northern and southern regions of the world, there tends to be more year-round prey. With more available prey, there is no reason for a Peregrine Falcon to leave its home. Even when they are raising young, the tropical regions of the world usually provide them with enough food to raise a healthy family.

Perhaps because of their amazing flying and hunting skills, Peregrine Falcons have had cultural significance for humans throughout history. To this day, they are still one of the most popular birds in the sport of falconry, and in ancient times they were considered the birds of royalty. Today, Peregrine Falcons that are trained as falconry birds are sometimes flown by their trainers at airports to scare off ducks and other birds that could collide with a plane and cause accidents. These falcons are helping to keep our skies safe! The Peregrine Falcon also appears on the U.S. Idaho state quarter.

Why they need our help

In the 1970s, when Peregrine Falcons began to disappear, scientists wanted to understand why. This led them to discover the environmental dangers of DDT, not just for birds but for other wildlife and humans as well. By studying Peregrine Falcons, we continue to learn more about long-term effects from other environmental contaminants.

To this day, Peregrine Fund biologists are studying Peregrine Falcon populations in the United States. Part of this work takes them to South Padre Island, Texas, to measure the effects of the large oil spill that occurred in the Gulf of Mexico in 2010. There they capture falcons using specially designed traps and bait. After the falcons are captured, biologists place a band on each bird’s leg and draw a small amount of blood to be tested and evaluated for signs of oil exposure.

By comparing these blood samples with samples collected before the oil spill, biologists will be able to detect changes in amounts and composition of pollutants. Because Peregrine Falcons are part of a fragile, complicated food web, scientists will be able to tell whether the oil spill is having long-term effects on a variety of wildlife. Learning about how these issues affect Peregrine Falcons can tell us how wildlife and humans may be affected as well. As in the case of DDT, this information can help stop the use of dangerous contaminants – good news for all of us.

What they eat

Peregrine Falcons are mainly bird hunters; starlings, pigeons, blackbirds, jays, shorebirds, and waterfowl are all fair game for a hungry Peregrine Falcon. They also occasionally hunt mammals, reptiles, and insects and there have even been reports of some Peregrine Falcons specializing in eating bats.

A hunting Peregrine Falcon uses many strategies for catching a good meal but they typically catch their prey in the air with fast pursuits, rapid dives, and other impressive aerial maneuvers for which these falcons are known and admired. Perhaps its most famous hunting technique is the dive. To pull this off, a Peregrine Falcon flies high into the sky, using its keen eyesight to locate birds flying below. When it finds its target, the falcon folds its wings and falls into a nose dive, or stoop, gaining speeds over 200 mph. The falcon closes its feet, and uses them to knock the prey out of the sky.

When not stooping after its prey, Peregrine Falcons go after their quarry in a swift aerial chase, flapping their wings furiously in hot pursuit of a meal. Though it cannot move as fast as when in a nose dive, a Peregrine Falcon, in horizontal flight, can still rival a cheetah for speed! Peregrine Falcons also may hunt from the vantage point of an exposed perch – once again using their eyesight to pick out an easy meal. At sea, Peregrine Falcons use ships, which provide high perches, to hunt for seabirds. Peregrine Falcons will sometimes dismember their prey and eat it in flight, or they will land with their prey in a safe spot, pluck the feathers, and eat. Pairs sometimes hunt together to flush, chase, and catch their prey.

Nest, eggs and young

When Peregrine Falcons are 1-3 years of age, they are able to start reproducing, or having young. When looking for a mate, male Peregrine Falcons, like many other birds, must work hard to impress the females. To keep her attention, males bring females food during the courting and nesting season. She frequently takes the prey from him while they are both in flight by turning upside down in mid-air and grabbing the food out of his talons!

Like most falcons, Peregrine Falcons do not build their own nests. They lay their eggs in scrapes, or small depressions, they make in the soil or gravel of a cliff ledge. Sometimes, they use abandoned stick nests that had been built in trees by other species. Today, more and more Peregrine Falcons are making their homes in cities. There, they nest on ledges of tall buildings and bridges.

The female lays three or four eggs, sometimes five, which are incubated for about 34 days. Though the male does help incubate, or sit on the eggs to keep them at just the right temperature, the female does the majority of the incubating. She relies on the male to bring her food. After the chicks hatch and as they are growing, both the male and female provide food for the young. To feed their chicks, the adult falcon uses its beak to rip up small pieces of meat and delicately pass them to the nestlings.

The young falcons grow up quickly. When they hatch, they are covered with fluffy white down and have very large feet in proportion to their bodies! But in just 5-6 weeks, the falcons are fully feathered and ready to fly. Even their feet, though still large, look just right for their bodies. After the young falcons fledge, or fly for the first time, they still stay with their parents for a few months before leaving the adults’ territory. These few months are spent learning to hunt and to survive on their own.

During the entire nesting season, the adult Peregrine Falcons are very territorial. They dive and chase after almost anything that comes close to their young, including birds and other raptors much bigger than they are! They often emit loud cacking sounds as they dive after, and sometimes hit, any intruders that dare to enter their territory.

Idaho Connection

Though making an extraordinary comeback after the banning of DDT and conservation actions by many organizations and individuals, the Peregrine Falcon is still not very common in Idaho. According to the Idaho Fish and Game Department, fewer than 30 historic nesting sites for these species were ever identified. Despite the fact that a pair is nesting on a tall building in downtown Boise, populations within Idaho are found mostly in the central and eastern portion of the state.

Peregrine Falcon and The World Center for Birds of Prey

The World Center for Birds of Prey is home to several Peregrine Falcons that help make our raptor education program a fun family event. During our fall flight shows, guests are often treated to the sight of a falcon (Peregrine or other species) flying swiftly over the open fields behind the amphitheater or maneuvering deftly among the crowd. Inside the visitor center, you will see falcons on display, giving you a close up view of these incredibly beautiful raptors.

Research Resources