Peregrine Falcon (Falco peregrinus). Photo Credit: Bob Gress The peregrine falcon has a distinctive black head with a “moustache” over its beak, continuing onto a blue-grey back. Its white underparts are barred. They nest as far north as the Arctic tundra and winter in South America. Homing instincts lead them back to their nesting sites (aeries) that have often been used by uninterrupted generations of falcons. Peregrine populations became endangered because of the widespread use of DDT during the 1950s, 60s, and 70s but have responded to curtailed use of DDT and other pesticides. DDT was believed to reduce the amount of calcium in their eggshells. Thinner shells broke prematurely resulting in poor hatching success. The peregrine falcon was removed from the U.S. Endangered Species list on August 25, 1999 and from the Kansas list in 2009. In natural surroundings, the peregrine falcon nests in a scrape on cliff edges. The female scrapes a shallow depression in loose soil, sand or gravel in which to lay eggs. No nest materials are used. In cities, man-made structures like bridges and building ledges have become substitutes for the cliffs as nesting locations. The peregrine is renowned for its speed, reaching more than 200 mph during high speed hunting dives known as stoops (wings tucked in close to the body). These dives take many different waterfowl and shorebirds plus pigeons, doves, flickers and meadowlarks. Their dramatic courtship flights showcase aerial acrobatics, spectacularly steep dives and precise spirals.