Threatened and Endangered Species

Federally listed endangered and threatened species are determined by the U.S. Fish and Wildlife Service under authority of the Endangered Species Act of 1973 and are listed in the Federal Register. Endangered and threatened animal species listed by the state of Maine are determined by the Maine Department of Inland Fisheries and Wildlife, and state listed plant species are determined by the Maine State Planning Office pursuant to the Maine Endangered Species Acts of 1975 and 1986, respectively. Maine critical areas are those areas designated by the Maine State Planning Office, pursuant to the 1974 Maine Act Establishing a State Register of critical areas, as worthy of special planning and management because of their natural, scientific, scenic, and historical values.

In keeping with the Endangered Species Act, the U.S. Fish and Wildlife Service was informally consulted concerning endangered or threatened species or critical habitats that potentially could be in the area affected by the General Management Plan. The service advised that two endangered species, the peregrine falcon (Falco peregrinus) and the bald eagle (Haliaeetus leucocephalus), and one candidate species, the harlequin duck (Histrionicus histrionicus), are known in the park.

Peregrine falcons: Probably never more than two pairs of these falcons have inhabited Mount Desert Island. Only two former aeries are known — one on the steep slope of Champlain Mountain near Bar Harbor, the other on the Eagle Cliffs of Saint Sauveur Mountain bordering Somes Sound. During the late 1950s this species was extirpated as a breeding bird on Mount Desert Island. Due to a cooperative reintroduction program, falcons nested successfully on Champlain Mountain in 1991 and 1992.

Bald eagles: These birds have traditionally inhabited the state of Maine, including habitats found in Acadia National Park. The Maine Department of Inland Fisheries and Wildlife formulated a bald eagle management plan that is being implemented in cooperation with wildlife personnel from the University of Maine and the U.S. Fish and Wildlife Service. As part of the management plan, an annual census is conducted to determine nesting activity, breeding success, population changes, and perturbation. Surveys indicate that eagles actively use areas within the park.

Harlequin ducks: The population of western Atlantic harlequin ducks has decreased dramatically in the last 100 years so that there are now only about 1,000 individuals. The largest wintering group of the western Atlantic sub-population is in the vicinity of Isle au Haut.The park also supports 38 plant and 59 animal species officially listed for special status by the state of Maine. Sixteen animal and seven plant species are of concern to park management and are listed in the Resource Management Plan. These species include natives that were possibly extirpated, species at the edge of their range, those representing genetic variability, and those whose numbers are so low as to be near the minimum viable population. A dozen registered Maine critical areas are on parkland.