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| PEREGRINE
FALCON |
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| The dashing, dark-eyed
peregrine falcon is a master of the air, and so great are its powers of
flight that it has established breeding populations on every continent
except Antarctica. The very word peregrine means "traveling"
(the word pilgrim comes from the same Latin root), and this falcon
is one of the most widely distributed birds in the world. It is also the
fastest animal in the world in its breathtaking stoops or dives, reaching
speeds of between 100 and 200 miles per hour. In level or horizontal flight
the peregrine is much slower, and can in fact be outflown by a pigeon. Like other falcon species, peregrines have long, pointed wings and a black line under the eye known as a mustache. Adult males and females are gray-blue on the back, wings and tail, although females have a brownish tint to their feathers. Both males and females have white or cream-colored chests, although the male tends to be whiter. Females are larger than males, something that is true of almost all birds of prey. Among falcons, males are known as tiercels because they are approximately 1/3 smaller than their mates. Wingspan of the males averages 38 inches across, while weight ranges from 1 pound to 1 1/2 pounds. Females have a wingspan that averages 44 inches across, with a weight range of 1 1/2 pounds to slightly over 2 pounds. Peregrines vary in size and coloration throughout their extensive range. The largest and most heavily marked birds come from islands in the Bering Sea, while one of the smallest forms occurs in India. North American peregrines (there are three recognizable forms that differ in markings and size) are intermediate between these two extremes in size. This is a bird-hunting specialist, knocking its prey out of the sky with a slashing blow from its powerful feet. The quarry is not snatched in the air unless it is very small; usually it is allowed to fall to the ground. There the peregrine may use a special projection on its upper beak to snap its victim's neck. Prey ranges in size from songbirds (especially those such as flickers, red-winged blackbirds and blue jays that show a flashy feather pattern in flight) to ducks, geese and even herons. Waterfowl is such a frequent target that the peregrine's old name was duck hawk. Another favorite prey is pigeons, which can occasionally cause the falcon problems. Peregrines are susceptible to a few lethal diseases and one of them, trichomoniasis, can be contracted by eating infected pigeons and doves. Another lethal problem for the peregrine has been modern agriculture's heavy dependence on pesticides. By the 1950s it was obvious that something had gone appallingly wrong with the falcon's breeding populations, and various causes were suggested. What was certain was that a deadly pattern of thin-shelled eggs and parental egg-eating was leading to widespread nesting failures and a catastrophic drop in the peregrine's numbers. By the late 1960s DDT had been pinpointed as the culprit, and by 1972 its use had been curtailed or banned outright in the U.S. But for the peregrine this good news came almost too late - it had already disappeared as a breeding bird east of the Mississippi River. The entire peregrine falcon population of the continental U.S. was down to 39 pairs. The plight of this magnificent species focused worldwide attention on the dangers of persistent pesticides, and scientists concentrated their efforts on captive breeding. To date more than 6,000 captive-bred birds have been released, and many are now raising young in the wild. In many cases the nesting sites aren't that wild - several cities, including Boston, Fall River and Springfield in Massachusetts, and Bridgeport and Hartford in Connecticut, now have peregrines nesting on the ledges of skyscrapers or under bridges. Peregrines find cities to their liking because tall buildings resemble the rocky cliffs they would ordinarily nest on, and food in the form of pigeons and starlings is plentiful. Many of the peregrine's former nest sites, used before so many of the birds were wiped out by DDT, have now been taken over by great horned owls or ravens. It may be that most of our peregrine falcons, at least in the Northeast, will continue to live in cities. At the present time, the total peregrine population of North America may be as high as 3,000 pairs. After being on the federal endangered species list since 1970, the peregrine was removed from the list in 1999, meaning that the specter of extinction no longer hovers over it. |
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