CITY PEREGRINES

     Peregrine falcons are a stately kind of raptor that traditionally has nested in crevices high in rocky cliffs, particularly near rivers, throughout much of the world.  Unfortunately, their numbers in the United States had been depleted in the mid-twentieth century due to the use of DDT pesticides, shooting and egg collecting.  However, in recent decades, they have made a strong comeback in the United States, to the point that they seem relatively common these days.  DDT use is a thing of the past, peregrines are protected by laws and, most importantly, they have adapted to raising young on the ledges of tall buildings and under large bridges over rivers, places that must remind them of shelves on cliffs.  All those human-made nesting spots are in and near cities.  

     Furthermore, peregrines have also adapted to rearing offspring in nest boxes erected on cliffs, usually near rivers.  Their adjusting to hatching youngsters on city structures and in nest boxes on cliffs has greatly increased their numbers throughout this country.      

     Many big and medium-sized cities in The States harbor one or more nesting pairs of peregrines in recent years.  New York City is a good example of that.  In 2019, for example, it was estimated that New York City had 25 pairs of nesting peregrines, which might have been the largest number for any city throughout the world.  And there might have been several unpaired, young adults at that time, and as many as about 80 young birds in their nurseries, all adding up to maybe 145 peregrines in New York City during that year. 

     And, it was stated that peregrines hatch chicks on or under every bridge over the Hudson River from Albany downriver to New York City.  Peregrines also hatch young under bridges over the Delaware River at Philadelphia, and on buildings in Philly and Wilmington, Delaware, for example.  It's no wonder peregrines are becoming ever more successful in this county.  

     Peregrine falcons are majestic, fast-flying birds that need great speed to catch flying prey in mid-air.  They prey mostly on city pigeons, but also on starlings, mourning doves, shorebirds along the rivers and other kinds of birds.  They fly high on long, swept-back wings and look down for potential prey.  When a victim is spotted, each falcon dives swiftly at it, strikes the bird with its padded chest, which kills or stuns the prey, which falls limply out of an explosion of feathers.  The peregrine dives after it and catches it in mid-air, then speeds to a perch to dine.  All that is exciting to see.

     Peregrines generally mate for life.  And every year each pair attempts to raise three or four babies to fledging, but not always successfully.  Another plus for peregrines rearing offspring in cities is there is little threat from large and fierce great horned owls who will kill baby peregrines when they can.  

     City-nesting peregrines have human-made ledges to raise young in comparative safety, abundant food in the form of pigeons and other birds, and freedom from harassing horned owls, and other kinds of predators.  And, in return, nesting peregrines are exciting to see flying swiftly after prey species above city streets.       

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