Peregrine falcons are now more numerous in New Jersey than they were historically.
“Falcons are a top-of-the-food-chain species, like eagles,” Clark said. “They were never as abundant as deer.” Twenty nesting pairs, she said, are more than the state had in the early 1900s.According to a report (pdf) on the state raptor website, there were 20 breeding pairs of peregrine falcons statewide in 2007. Of those, 4 nested on cliffs in the Palisades, 13 on towers and buildings, and 3 on bridges. New Jersey sent 12 young falcons to Virginia and West Virginia to help recovery programs there.
“There were at least six pairs at the Palisades Cliffs,” she said. “And we have some historical data that there were four to five pairs along the upper Delaware River. That’s it.” ...
“We never set a numeric goal for the population, because when we started, we didn’t have good historic information,” Clark said. “But one of our milestones was always to get them back into historic habitat.”
That natural habitat is Palisades Cliffs. Early attempts to place fledgling falcons at what are called “hacking” sites at the cliffs failed. “The release of young birds didn’t work in the cliff area,” Clark said, “because they were eaten up by great horned owls.”
Hacking, or hack sites, refers to feeding the falcons, while allowing them to fly and go wild as they learn how to hunt for themselves.
Adult falcons can stand up to the big owls, but the fledglings weren’t yet strong or smart enough. So the state shifted its repopulation efforts in the 1980s to towers in salt marshes.
There were fewer predators there. As a result, the birds did well in New Jersey and other states. “The salt marshes were the engine that fueled the recovery,” Clark said. “Here and in Delaware, Maryland and Virginia.”