The Peregrine Falcon (Falco Peregrinus, or Wanderer Falcon) is a raptor found, amongst other locations, in North America. Three subspecies are indigenous to areas there; one off Alaska (Falco Peregrinus Pealei), one in sub-Arctic North America (Falco Peregrinus Tundrius) and one which at one time spread across the greater North American continent from coast to coast, reaching perhaps half way down the current contiguous states of the U.S.

Recent History of the Peregrine

The Peregrine is a hunter; a bird of prey. It sustains itself on small mammals or birds, killed in flight. One of its favorite meals is pigeon, which turned out to be quite handy in recent years; more on this in a moment. In the 1950s and 1960s the Peregrine population of North America went into a precipitous decline. The species appeared headed for extinction. A group effort among research scientists and professional falconers turned up a likely cause. Healthy, adult female falcons were laying eggs with extremely thin and brittle shells. As a result, the weight of the mother bird was crushing the eggs. Many nests with such smashed eggs were located. Research showed that the biochemistry of the birds' reproductive system and metabolism was imbalanced; not enough calcium was being retained and deposited onto the eggs as they were being formed and laid.

After a great deal of investigation, it was discovered that DDT, a pesticide then quite popular in the U.S., was to blame. Although the traces of DDT in the environment were not nearly enough to harm the falcons directly, the falcon was far enough up the food chain that bioaccumulation meant that they were receiving very high amounts in their diet. DDT, in sufficient quantities, was shown to disrupt the calcium levels of the birds as well as have other deleterious effects.

Following this discovery, a large lobbying and education effort managed to help secure a near-total ban on the use of DDT in the U.S. and worldwide, which went into effect in 1972. By this time, the falcon population was in dire straits; in 1965 no chicks were fledged (raised to the point of leaving the nest) successfully anywhere in the Central or Eastern U.S. The ban appears to have halted and in fact reversed the decline of the peregrine - one of few such success stories in environmental policy history. Peregrines, which have no natural predators as adults, rebounded. The falconers and scientists discovered that unlike many species, the human development of their habitat was not necessarily a lethal interference. Peregrines prefer to nest in the tops of dead trees, where their eggs and chicks are safe from ground-based predators and where the parents can watch over both their young and nearby airspace for food or threats to those chicks. Crows, for example, often prey upon small peregrine chicks or eggs, dragging them from the nest if the parent isn't watchful enough.

However, dead trees share many of these advantageous characteristics with some manmade structures. The researchers found that peregrines would happily and effectively nest on large power-line support towers, as well as in cities on the sides, ledges and tops of skyscrapers. In the latter case, their favorite food (pigeon) was in fact in oversupply; very little effort was required on the adult falcons' part to feed their young, meaning they could spend more time watching over the nest.

It has been eight or ten years since peregrines were first nested on power lines. It is estimated that the percentage of the peregrine population that was fledged in such nests is as high as 30%. Those placed in cities not only enjoy fewer predators and more food, but usually the avid attention and guardianship of the inhabitants of their nesting towers, the modern U.S. office workforce. Websites and newsletters abound as everyday folk discover the thrill of watching these birds raise chicks and of participating in the rescue of a species. Webcams can be found all over the Internet which offer live views of falcon nests, both in the wild and in urban settings. Peregrines, luckily, don't seem to mind such mechanical observation.

The Peregrine was removed from the Endangered Species List by Secretary of the Interior Bruce Babbitt in August of 1998. This is a mixed blessing; while it reflects the species' amazing recovery, it also removes protections that many feel should be maintained.

Peregrine Facts

The Peregrine is not an enormous bird. The female, fully grown, typically is comparable in size to a crow; perhaps fifteen to twenty inches in length with a wingspan of twenty to thirty inches. Males are slightly smaller than females. Peregrines do, however, have one enormous weapon in their struggle for food and survival - speed. Peregrines have been clocked at speeds of up to 215 MPH when stooping, or diving upon their prey. They have amazing eyesight; I have witnessed a Peregrine circle a field perhaps eight hundred feet in the air before suddenly folding its wings and plummeting. When we reached the bird, it was proudly sitting atop a mouse it had seen and taken, breaking its neck on impact in a typical falcon kill. This mouse was visible to the falcon 800 feet up, in a heavily-grassed field.

They are beautiful creatures, in my opinion. Fully-grown females typically have dark guard feathers on their backs, wings and shoulders, with a spotted white underbelly and underwing area. The spots are dark brown and/or black. The head is usually dark, with white tracings around the eyes. Even the bird's coloring screams fast! They have sharply-hooked beaks, used for tearing flesh and for breaking bones; talons designed for gripping a target at 215 MPH and holding it, and their eyes are black spheres.

Although falcons lead dangerous lives, some have been known to live 15 years or more. Young falcons begin breeding at perhaps two or three years of age. The average clutch of eggs hatches between three and six young; usually only two to four will survive to fledge.

Peregrine Behavior

I was privileged enough to spend three months one summer at age 16 volunteering at the Cornell University Raptor Research Center, on Sycamore Woods road in Ithaca NY. There, I cleaned cages, fed birds, assisted in any way needed, and generally did a lotta work. The most precious thing I took away from that time was the experience of interacting with falcons; not just peregrines but gyrfalcons, goshawks, kestrels and even an enormous Bateleur Eagle from South America. Although beautiful and lethal, Peregrines really aren't that smart, but that's okay; they don't need to be. They can, however, communicate with humans to some degree. I learned to ask if a bird was ready for dinner by making small peregrine-style cries while fluttering my arms, folded at the elbows, to simulate ruffling feathers. If it was, it would usually pump its head up and down and call back; if not, it would either ignore me or wait until I was finished and then look away. A few other messages could be passed, as well.

There were two types of birds at this facility. One set of birds were quarantine birds; the center acted as a U.S. Dept. of Fish & Game/Dept. of Agriculture quarantine site for falconers bringing their birds into the country. These falcons were familiar with humans, and what is known as imprinted; they had developed bonds with their owners, and 'thought' of themselves as humans. Consequently, you could feed them from your hand and interact with them as much as you liked. Some were quite conversational.

Others were research or rescued birds, and these demanded special care. One problem these birds have is than once imprinted, falcons have no fear of humans, and would fail to avoid humans in the wild who might harm them. Also, once having seen humans feed them a few times, they would begin to habitually approach humans for food rather than hunt. In order to prevent imprinting, we would feed the birds by pushing their food (usually a quarter or half a chicken, still feathered) through a hood with a curtained opening. The food would fall to a small platform, and the bird would fly over to eat - without seeing a human.

For these birds, we observed them through one-way mirrors, tried to avoid any human sounds near them, and in general made as much effort as possible to prevent them from seeing their keepers. Some were released into the wild while I was there, successfully rehabilitated from injury or having been raised from a chick. Chicks were raised on a diet of ground baby quail.

Believe it or not, this is a Nodeshell Rescue. Original nodeshell by the now-defunct DMan.
  • The Raptor Research Project. Website:
  • Zimmerman, David R. To Save a Bird in Peril: Coward, McCann & Geoghehan, New York, 1975.
  • The Peregrine Fund. Website:
  • The Raptor Research Lab at Cornell (Moved now to Boise, Idaho)
  • Personal experience
  • Environment Canada. Website,
  • ABC News

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