Fierce and swift, steel blue in color and called the world’s most perfect flying machine, the peregrine falcon is heading toward extinction in North America. The reason: DDT. Perilously high levels of the pesticide and related chemicals have been found in the eggs, fat and tissues of the birds…. [The falcons] are not picking up the DDT directly, but get it by eating other birds which, in their southern migrations, ingest DDT-contaminated insects. — Science News, February 22, 1969
Update
Two years after the American peregrine falcon (Falco peregrinus anatum) was declared endangered, the United States banned DDT in 1972. The pesticide lingered in the environment, however, and by 1975, North America’s population of peregrine falcons hit a low of 324 nesting pairs. State and federal agencies worked with conservation groups to breed the species in captivity, with some 6,000 birds released into the wild since 1974. The species was removed from the U.S. endangered species list in 1999.