February 18, 2011

Finding Peregrine falcons in the city or the art of smelling fear

Robert Bateman
Peregrine falcons have seen a remarkable turnaround since the dark days of pesticide use in the 1940s to early 1970s. The story is well known; toxins from pesticides like DDT accumulated in the soil and water climbing the food chain through "big fish eat little fish" only to accumulate in the largest predators. One side effect for these “top dog” birds like Peregrine Falcons, Bald eagles and Osprey was under formed eggshells incapable of protecting the embryo during incubation. The eggs simply crushed under the weight of the parent bird. With plummeting reproduction rates the peregrine’s population collapsed and in 1970 it was placed on the Endangered Species List. Local data confirms this trend. The Peregrine falcon was not recorded breeding in Massachusetts during the Breeding Bird Atlas of 1974. A 2007 Breeding Bird Atlas confirmed or probable confirmed breeding Peregrines in 15 of the 1055 “blocks” in Massachusetts. Compare these 15 reports to the over 500 reports of breeding Red-tailed hawks in the same atlas project. 
Silent Spring
The Peregrine falcon was removed from the Endangered Species List in 1999 but their numbers in Massachusetts are still low. This is due in part to the Peregrine’s preference to nest high on rocky cliffs. Mimicking these sky-scraping nesting grounds, peregrines have found skyscrapers themselves to be an adequate substitute. One innovative solution to city nestingAnd with downtowns replete with robust populations of pigeons and starlings the falcons have grown comfy in such urban settings as Worcester, Massachusetts.

Worcester has played home to one such pair of breeding falcons for the past few years and hopes are alive that the pair will take to a new nest site on the Printer’s BuildingHaving falcons nest in the city is simply put… amazing. Finding these 14”-19” birds high above city streets can be a challenge. Look for dark “gargoyles” perched on the roof line of tall buildings, or the ledges beneath windows. Accumulation of “white wash” is a good sign of a favorite hunting perch. Since falcons hunt entirely on the wing watch for close knit flocks of starlings or pigeons flying in tight, evasive patterns, this is often a sign that a falcon or other raptor is close by, "shepherding" the flock until an individual bird strays from the pack.

Join me on Sunday, February 20th at 10am for the Peregrines and Pediments walk sponsored by Broad Meadow Brook and Preservation Worcester.

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