UPDATE 7/29/2016: Park today announces reopening of Precipice, Jordan Cliffs and parts of Valley Cove Trails, and closure of 1-mile section of Valley Cove Trail between Flying Mountain and Man o’ War Brook because of deteriorating trail conditions.

A biologist at Acadia National Park said several popular hiking trails at Acadia National Park should open by early next week, following “a great” year for the peregrine falcon at the park.

Bruce Connery, wildlife biologist at Acadia, said 11 peregrine falcon chicks fledged, or took their first flight, at the park’s three main nesting sites this year. That’s up from 7 for each of the prior two years at those sites.

He said the peregrine falcon nests at the Precipice on the east face of Champlain Mountain and Jordan Cliffs each produced four fledged falcons and the nest at Valley Cove, three.

“It is great,” he said in an interview on Wednesday. “We usually have good success at one site, sometimes two. It is a rare to have that kind of success at three sites.”

He said there was also a chick of the peregrine falcon at Ironbound Island this year with a photo taken by the Bar Harbor Whale Watch Co. The park holds a conservation easement on Ironbound, a privately owned island in Frenchman Bay.

The Precipice Trail, the Jordan Cliffs Trail, part of the Orange & Black Path and the Valley Cove Trail, which were closed early this spring to protect the falcon chicks, should all open maybe this weekend or by early next week, he said. The trails usually do open in early August every year.

The park has not officially announced the date for reopening the trails and trail crews still need to approve some trail sections for safety reasons for hikers, he said. The park announced the trail closures in March.

Banner year for the peregrine falcon in Acadia National Park

Fledged chicks at the three key sites on Mount Desert Island rose by more than 55 percent.

Last year, for example, there were three fledged peregrine falcon chicks at the Precipice and two each at the Jordan Cliffs and Valley Cove sites.

In 2014, there were four at the Precipice, two at Valley Cove and one at Jordan Cliffs.

There were two at Ironbound Island in 2014.

Connery said the falcon chicks did well this year possibly at least in part because of a very mild spring and mild June with a lack of severe weather. There were no long periods of damp weather that would challenge survival of the chicks and foraging by the adults was easy, he said.

Most of the fledged chicks have moved on, but there is one chick that was returning to the nest at the Precipice.

He also said he spotted one adult falcon in January at the Precipice and a male and female around the end of February. He said he is assuming the adults remained in the area for the winter, though they were not banded. Because of a growing number of bird feeders, more smaller birds remain in Acadia in the winter, providing more prey for the falcons.

At times during the winter, the adults flew away for two to three days and then returned. Falcons can fly 200 to 300 miles in a day. He said he would guess that if the falcons remained in the park on all days, their prey – mourning and rock doves and blue jays, for example –  would become secretive and more difficult to catch.

Peregrine falcons have made a comeback since becoming nearly extinct in the mid-1960s. The falcons were reintroduced into the Maine national park in 1984, and have been returning on their own to nest successfully from 1991 to the present, according to the U.S. Department of the Interior’s “A Guide’s Guide to Acadia National Park.”

Connery said the recovery of the peregrine falcon stemmed from the EPA’s banning of the pesticide DDT in 1972.

Because of the pesticide, many eggs did not hatch and the populations precipitously dropped until a mere 12% of normal peregrine falcon populations remained in the United States, according to the Nature Conservancy.

Falcons ate other birds that fed on seeds and insects, for example, contaminated with DDT.

The peregrine falcon was listed as a federal endangered species in the early 1970s, but was removed from that federal list in 1999. The first successful nest in 35 years in Acadia occurred in 1991.

The resident breeding population of peregrines remains endangered under Maine’s Endangered Species Act.

The peregrine falcon is a great success story that’s being played out in Acadia National Park.