June 30th - July 4th
An adult Peregrine Falcon seen in downtown Bar Harbor.
Photo by Jazmine DeBeauchamp
The juvenile Peregrine Falcons have been taking to the skies daily since their first flight. The siblings have been seen chasing each other through the air as a way of practicing their diving and prey-capture. They alternate between circling each other, colliding, and soaring side-by-side along the cliffs of Champlain. Their maneuvering seems to have improved since last week, but their landings are still a bit shaky. The fledglings also aren't quite ready to begin hunting for themselves. To hunt successfully, they'll need to continue working on strengthening their wings to support long-distance flights, and they'll need a bit more practice to perfect their stoop (diving after prey). This means the adult Peregrine Falcons are still responsible for bringing food back to the two fledglings to give them the best chance at reaching adulthood. Peregrines will fly up to 5-10miles to find food if needed. In fact, a Peregrine was even spotted feeding on a pigeon in downtown Bar Harbor! Although we were unable to confirm that this bird was one of the adults from the Precipice site, it is within their range. At the Peregrine Falcon Watch Program, we were able to see one of the parents exchange food with a fledgling. The adult flew in from the East, screeching, which alerted the juvenile of its return. The parent Peregrine Falcon then dropped a bird on a ledge, which the fledgling descended on to eat its meal. After eating, the juvenile bedded down in some grass and stared out over the ridge.On Tuesday afternoon, an adult Peregrine Falcon returned with a meal of its own. From the Precipice Lot, we could see feathers surrounding the Peregrine and red marks on its chest, likely remnants from its last meal. Afterwards, we were able to watch the adult preening itself and napping for nearly an hour. The adults will stay in the area for another month to keep supporting the juveniles as they gain independence. We’ll likely continue seeing all 4 of the Peregrine Falcons flying around the Precipice Trailhead lot for the rest of July!
Over the past few days, the Peregrines have shown that they can be voracious predators. Peregrine Falcons sit at the top of the food chain, which does have some perks; as adults, Peregrine Falcons don’t have to devote energy to evading predators. However, being a top predator can have its downsides, and the Peregrines have experienced them firsthand in the past. Because the Peregrines exclusively eat other birds, they consume any toxins that their prey have eaten, which can lead to a buildup of contaminants in their system. This is an effect called bioaccumulation. In the 1960s and 1970s, the widespread use of a pesticide called DDT led to a buildup of DDT in the tissues of the birds that Peregrine Falcons feed on. The DDT bioaccumulated at the top of the food chain as the Peregrines incidentally consumed increasing amounts of the pesticide. Unknowingly, this caused thinning in their eggs and a significant decline in nesting pairs of Peregrine Falcons in the U.S.
The nesting pairs we can see at the Precipice Trail and across Acadia National Park are here thanks to the continued restoration efforts of biologists since the 1970s. After the use of DDT was banned in the U.S., scientists began a process called hacking, where Peregrine Falcon chicks were captive-raised on cliffs to motivate them to return to the sites when they were ready to breed. In the mid-1980s, the first signs of success were observed on Jordan Cliffs when one of the captive-raised chicks returned to the site as a breeding adult. Since then, Acadia has been the breeding site for multiple pairs of Peregrine Falcons nearly every year!