ACADIA NATIONAL PARK (AP) – Peregrine falcons have returned to Acadia National Park, prompting rangers to close parts of the park’s trail system to the public.

The area around Precipice Cliff will be closed until further notice after falcons were seen last week defending their nesting territory and engaging in breeding behavior, said park Superintendent Sheridan Steele.

Peregrine falcons, which have nested at Acadia since 1991, are protected under the Maine Endangered Species Act.

To protect the birds from being disturbed, the popular Precipice and East Face trails on the east side of Champlain Mountain have been posted. Those trails were already closed because of damage from a series of small earthquakes last fall, but the new posting reinforces the earlier closures.

Trails would normally remain closed until about five weeks after falcon chicks first take flight, usually in late July or early August. This year, however, the trails will remain closed until a trail crew can repair sections of the trail that were damaged or blocked from the earthquakes.

If the park biologist determines that any nesting attempts have failed in the Precipice Cliff area, the park will open the trails once the repairs have been completed.

The peregrine falcon was placed on the federal endangered species list in the early 1970s after its population declined from pesticides and habitat loss.

Acadia was chosen as a falcon reintroduction site in 1984, and the first pair of falcons successfully nested on Champlain Mountain in 1991. Since then, falcons have established other nesting sites on Beech Cliff above Echo Lake and at Jordan Cliffs.

In 1999, the bird was removed from the list of species receiving protection under the federal Endangered Species Act.