Ratcliffe’s next survey, in 1963, showed a further dramatic drop in peregrine numbers, especially in the south, where only three pairs were found. Again, it was only in remote areas of Scotland that the birds were unaffected. Reports coming in from Europe documented a similar decline in bird populations, including peregrines.
The Fight to Ban DDT
As more people became aware of the death of so many birds, there was a great public outcry. The British government tasked scientists at Monks Wood research station with conducting studies on the adverse effects of pesticides. Meanwhile a series of “voluntary bans” were recommended, restricting the use of organochlorines and other toxic pesticides. Rat-cliffe had found that even occupied eyries (nests of eagles and falcons) often contained broken eggs. Suspecting that chemicals were affecting the thickness of the eggshell, he took an addled egg to Monks Wood for testing. It contained traces of DDE (the residual product of DDT) and other chemical pesticides.
Thus the British team had already been studying the effects of chemical pesticides when Rachel Carson published Silent Spring in 1962—the results of her own research into why thousands of birds and insects in the United States were also dying. And reports coming in from Europe documented a similar decline in bird populations, including peregrines, also thought to be caused by pesticides.
In the United States, Joe Hickey, a professor at the University of Wisconsin, was one of a number of ornithologists and falconers concerned by a seeming decline in the peregrine populations. In 1939, he had made an extensive survey of active nest sites of the Appalachian peregrine east of the Mississippi. In 1963, he enlisted Daniel Berger (who had been making annual surveys of the peregrine population along the Mississippi for thirteen years) to undertake a survey of nest sites in the areas he (Hickey) had covered more than twenty years before. In 1964, Berger and his teammate traveled to fourteen US states and one Canadian province. They found no occupied eyries and saw not one peregrine for the whole three months. The crash of the Appalachian peregrine population in the eastern US was total.
Soon after learning this shocking news, Hickey heard about the pesticide situation in the UK from Ratcliffe. He at once set about organizing a gathering to which all interested parties were invited: falconers, scientists, government officials, even representatives of the agriculture and pharmaceutical companies. The Madison Conference, as it came to be known, took place in Wisconsin in mid-1965. There Ratcliffe explained to the assembled group what was going on in the UK. And he reported on a conference he had just attended involving seventy-one scientists from eleven countries in Europe, who had concluded that persistent pesticides in general, and the organochlorines in particular, posed a major threat to wildlife.
“Almost immediately after the conference people started looking at eggs and also tissues of Peregrines that had died—and they found both DDT and the residual product DDE,” Tom Cade wrote. “From that point on, it was pretty clear that DDT was the main problem the Peregrines were facing.” But more scientific “proof” was needed to convince governments to legislate against the use of these poisons given the determined opposition from the agrochemical and agricultural industries. These interests claimed that causal correlation between thinning of eggshells and the use of some pesticides was circumstantial.
So Ratcliffe designed a way of calculating the thickness of an eggshell based on its weight, length, and breadth as measured with calipers and used it to examine eggs in collections throughout the UK. He found a marked decrease in thickness from 1947 onward. Meanwhile, at the Patuxent Wildlife Research Center of the US Fish and Wildlife Service, scientists were investigating the effects of DDT and DDE on different bird species, including kestrels. Their experiments showed that relatively small amounts of various chemicals could lead to eggshell thinning in kestrels, and that this correlated with the situation of wild kestrels contaminated with pesticide-affected prey.
“Restrictions on DDT Will Never Happen”
The scientific evidence was mounting, but opposition remained strong. Indeed, one of President Lyndon Johnson’s scientific advisers at the Madison conference stated that “restrictions on the use of DDT will never happen.”
“That statement,” Tom told me, “served as a challenge for many of us.”
Pesticide regulation was the responsibility of the newly formed Environmental Protection Agency (EPA), which, under a court order instigated by the Environmental Defense Fund, started hearings on DDT in mid-1971. They called 125 witnesses over eight months, after which William Ruckelshaus, appointed first EPA administrator by President Nixon, courageously banned DDT nationally, with the president’s support.
The inevitable appeal was overturned by the US Supreme Court. The evidence given by so many scientists on the effects of the chemical on birds of prey, particularly the peregrine, bald eagle, osprey, and brown pelican, could not be refuted. It was a long, hard fight, but it resulted in a major victory for conservation, and set legal precedents in environmental law that have had far-reaching benefits for the environment.
In Canada, DDT had already been banned, and in several European countries conservationists had also been lobbying for legislation against the use of DDT and other harmful chemicals. In Britain, the government’s voluntary bans on the most toxic chemicals used in pesticides, along with farmers’ reductions in the amounts they used, meant that most had already been phased out by 1979, when the European Union finally banned their use.
Discovering the Nature of Peregrine Breeding
In anticipation of an eventual ban on the use of DDT, Tom Cade founded the Peregrine Fund in 1970 and began plans for a captive breeding program with the goal of reintroducing peregrines into the eastern United States. However, very little was known about breeding them in captivity, although a handful of falconers in the US and Europe had achieved some success. In the late 1950s, when some falconers had already noticed that peregrine populations seemed to be in trouble, they formed the North American Falconers Association, and forty-five falconers from many states had attended the founding meeting in 1961 to discuss the situation. Some had suggested captive breeding.
Tom is a falconer himself, and again and again as he moved ahead with his ambitious plan, he sought advice and help from other falconers. It was thanks to them that he knew that young peregrines can learn to hunt without parental tutelage. And falconers had practiced “hacking” since the Elizabethan era: They would haul a hack—a kind of wagon—to the top of a hill and put falcon chicks on it just before they were able to fly. Food was delivered each day, and after fledging, the chicks could come and go at will. When they had developed muscle tone and could catch birds for themselves, they were recaptured for training. Clearly, hacking would be part of Tom’s reintroduction plan. Most importantly, falconers knew that the nature of the peregrine was well suited for breeding in captivity. Tom wrote, “Although master of the sky and a denizen of wild and haunting landscapes, the Peregrine has also for centuries been … a bird that because of its gentle and placid disposition comes readily to the hand to do man’s bidding… .”
Because he taught at Cornell University and was associated with its famous Laboratory of Ornithology, Tom was able to establish a breeding facility there, affectionately known as Peregrine Palace. For some of his first birds, he turned to Dr. Heinz Meng, a professor at the State University of New York–New Paltz. A keen falconer and a Cornell alumnus, Meng had set up his own small breeding program, and he lent his breeding pair, and their offspring, to Tom’s program.
Through trial and error, Tom and the Peregrine Fund staff learned how to breed the greatest number of birds in the shortest time. The program incorporated natural breeding by pairs of falcons, double- or even triple-clutching, and artificial insemination, with the resulting eggs hatched either by nesting peregrines or in incubators. Gradually they learned that success depended primarily on the age at which a bird entered captivity (older individuals seldom bred) and how the nestlings were handled. They found that i
t was best to raise chicks in groups and take them, at five weeks of age, to the hacking boxes that were being set up in suitable places throughout the country.
Phyllis Dague and Jim Weaver, in particular, played key roles throughout the program. “Those two ran the program at Cornell,” Tom told me. “Phyllis did everything—secretary, accountant, fund-raiser, baby bird feeder, field assistant.” For several years, Phyllis actually lived at Peregrine Palace since Tom felt that someone should be with the birds at all times. Initially there was not even a window in the place, and in Return of the Peregrine, Phyllis describes dark windy nights spent on her own, living in the Peregrine Fund’s “office.” Indeed, that office, despite its annual condemnation by fire marshals, was used by a small group of people to accomplish great things.
Jim Weaver was also recruited in the early days at Cornell. Tom told me that Jim had a wonderful talent for handling the birds and keeping them fit in captivity. Even more important, he was a great manager and great team leader, and he recruited a team of loyal and dedicated co-workers. One was Bill Burnham who, after years of working on the restoration program, eventually founded the World Center for Birds of Prey. He was president of the Peregrine Fund until his premature death in 2006 at the age of fifty-nine.
Peregrines in Love
One of the things I have enjoyed when researching this story is the descriptions of the different peregrine personalities. I loved reading about a particularly feisty male in the Cornell breeding program named Sergeant Pepper. He terrorized rather than bonded with the females offered to him as mates. But then, after rejecting eight females in succession, “he fell in love with a little Latin lady from Chile,” wrote Tom. The two birds immediately accepted each other. “They started courting and he began feeding her. And even though she came to us in the middle of her molt, she somehow accelerated her molt and came back into breeding condition that spring. And they produced a lot of young every year after that.”
Artificial insemination, or AI, is considered a necessary tool only when a female refuses to accept a male’s courtship—or when a male refuses to mate with any female. Such a male was BC (Beer Can), who was collected from the wild when he was two days old. BC was hand-reared and imprinted on humans, and he utterly rejected females. When he became part of the breeding program, therefore, he had to become a semen provider for AI, and William Heinrich was given the job of “stripping” BC by hand. This was stressful for BC—“and very undignified!” said Heinrich. So when he heard that Les Boyd had designed a “copulation hat,” he persuaded him to come and explain how it worked.
Les told Heinrich to climb up to one of the nesting ledges in BC’s chamber, carrying a dead bird. When BC flew to take the offering, Heinrich had to make eye contact while imitating the ee-chip courtship call, then bow so that his head was level with the ledge—thus enabling BC to copulate with his hat. Heinrich accordingly ee-chiped and bowed: BC merely fed contentedly on the dead bird. Les instructed Heinrich to repeat the whole performance—from making eye contact to bowing—until BC showed some interest. When Heinrich was patiently doing this for the tenth time, Les could not stop himself from bursting out laughing—and Heinrich, thinking he had been made to look an idiot, climbed down and said he was quitting.
Propagation biologist Cal Sandfort patiently wearing a “copulation hat.” According to Bill Heinrich, Cal has probably raised more captive-bred peregrines than anyone in the world. (Peregrine Fund File Photo)
It took some time before a contrite Les was able to convince him that he had been really close to success and that his antics—while hilarious for a human observer—were far from absurd so far as BC was concerned! And so Heinrich carried on, repeating his “hilarious” courtship three times a day. And two days later, BC became the first voluntary semen donor to the Peregrine Fund. From then on, he provided good-quality semen several times a day, willingly—and perhaps joyfully! The results traveled far and wide across North America in the form of the scores of young birds he had, unknowingly, sired.
Return to the Skies
In 1974, the Peregrine Fund sent the first four youngsters from the breeding program for experimental release into the wild. Two were fostered to a wild pair in Colorado that had lost one lot of eggs (due to thin shells) and was incubating a second, dummy clutch (provided by the Peregrine Fund). These dummies were exchanged for the two captive-born chicks—they were accepted and raised successfully. The other two captive-bred chicks went to Heinz Meng, who had built a hacking facility on top of a ten-story tower on his university campus; they, too, fledged successfully. These were the first experimental releases of captive-born peregrine falcons in the United States.
The following year, sixteen chicks were sent to five hack sites in different places. Many of these young birds returned to the hack sites, or nearby, the following year. “When so many individuals came back in 1976,” said Tom, “I was fairly confident that we could successfully release more, and that we had a good chance of bringing this species back.”
During that period, Tom told me, “falconers from around the US lent me their peregrines to contribute to the breeding effort.” They also shared hacking techniques long known to falconry, which proved invaluable for the reintroduction to the wild. Indeed, all releases were initially carried out by falconers, although, as the project became widely known, hundreds of volunteers from all walks of life supported them as “hack site attendants.” This was a tough assignment, involving camping out at hack sites for weeks, enduring heat, cold, and insects, not to mention close encounters with bears and moose, bites from rattlesnakes, and even wildfires. Yet almost all accepted the hardship uncomplainingly, and developed a deep respect for the birds whose future they were helping to assure. “A Peregrine owns the air like nothing else I have ever seen,” wrote Janet Linthicum, one of the hack site attendants. Many volunteers went on to careers in conservation biology.
In 1976, there was a high survival rate among the peregrines that were released in five states; by the 1980s, the Peregrine Fund was introducing the birds into more than a dozen states in the eastern US—from Maine to Georgia—and in several Rocky Mountain states. Of course the project had its critics. Some scientists were concerned that genetic purity was being lost since peregrines from Alaska were breeding with individuals from Canada, Mexico, South America, and Europe. However, as Tom points out, “There were no eastern stocks left in the US, and we used a combination of whatever we could find to replace them. However, the preponderance of the breeding stock came from North America.”
Other critics feared that the introduced birds would not be able to adapt to their new environments because individuals from populations that migrated long distances were being used to build up new populations in the East, where peregrines had traditionally migrated only short distances. “But it all worked out okay,” Tom said. “Some of the released birds from Arctic stock did make fall movements into South America, particularly in their first year.” Others did not migrate at all, and none are known to have migrated to the Far North.
Total Restoration—Realizing a Dream
In this chapter, I have so far concentrated on the struggles and eventual success of the program in the eastern United States—because it was there that peregrines had become completely extinct, and their recovery was due entirely to captive breeding and reintroduction. But as Tom Cade pointed out, the aim of the Peregrine Fund was to restore populations of these magnificent birds to pre-DDT numbers throughout their range in the United States. In fact, as Tom stressed, most of the recovery of the peregrine in North America occurred naturally, through increased survival and increased reproduction of residual populations after DDT was banned. The Arctic peregrine falcon (Falco peregrinus tundrius) recovered naturally, with no captive breeding or reintroductions. And peregrines recovered well on their own in most of the Southwest and Mexico. In the West—California, Colorado, New Mexico, Utah, Idaho, Washington, Montana, and Wyoming—natural recovery was boosted by releasing captive-b
red birds.
The Peregrine Fund built a second breeding facility in Colorado in 1975, and under Jerry Craig, the program reached its target of producing more than a hundred birds per year by 1985. There was also a recovery program under Richard Fyfe for southern Canada. This covered the range of the anatum subspecies, and only anatum peregrines were used for captive breeding. Taken together, Tom told me, these programs released nearly seven thousand young peregrines by hacking, fostering, and cross-fostering.
In Gratitude
In 1999, the Peregrine Fund held a celebration to mark the day that the peregrine was officially removed from the endangered species list, and more than a thousand people attended. In his address, Tom said: “My dear friends and colleagues, you and I have fought the good fight for the Peregrine, and we have won a great victory… . What we have accomplished together is truly phenomenal, and I believe that the recovery of the Peregrine will be recorded in the annals of conservation as a major event of the twentieth century. But, as we all know, conservation is a continual series of challenges—the fight for conservation never ends—and so I exhort you: press on to meet new challenges, for they surely await, and will always be waiting, for those who strive to keep the earth fit for life in all its many splendored forms.”
Thanks to the successful reintroduction of the peregrine falcon in the major cities, Americans were given a new pastime. Shown here, an adult sitting on eggs on the 24th floor of the Union Central Building, Cincinnati, Ohio. (Ron Austing)
Hope for Animals and Their World Page 11
