Get to know Maine’s wildlife!
Maine is a place of diverse creatures, some familiar, some not so well known.
Visit our Creature Feature often to learn a little more about what makes Maine so special.
photo by Beth Dimond Bald Eagle
|
Few birds are more conspicuous than the Bald Eagle—national symbol, year-round resident of Maine, and Endangered Species Act success story.
The Bald Eagle, also known as the American eagle since it occurs only here, is especially noticeable in winter, when eagles from the North and West move to the coast, where the climate is milder and the coastal waters are free of ice. In the winter they roost and hunt in groups, feeding in open water along large tidal rivers of the Maine coast, or perched on frozen ice in search of discards from the fishing shacks.
The eagle’s white head and tail are more striking now, when the contrast is mirrored by the white-washed landscape; these white feathers are the origin of the eagle’s name, which comes from the Old English word “balde,” meaning “white.” A white head and tail are indicative of a mature eagle that is at least five years old.
Eagles have been monitored by Maine Audubon and state and federal wildlife agencies since 1962; monitoring became more extensive and rigorous after the species was placed on the Endangered Species List in 1978. After listing, the breeding range and number of nesting pairs slowly increased throughout the state, from 85 two decades ago to 385 today. Among the lower 48 states, Maine ranks eighth in abundance of breeding eagles, and is the stronghold for the species in the northeastern U.S.
Removed from the Endangered Species List in 2007, Bald Eagles continue to be protected by the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act. Both federal laws prohibit killing, selling or otherwise harming eagles, their nests, or eggs.
While the Bald Eagle population has made a comeback, reproduction rates are still low in Maine, mainly because of chemical contamination of their food web. Unsafe levels of persistent organic chlorine compounds like PCBs and DDE (a derivative of DDT) continue to impair the productivity of nesting pairs. Mercury poses another problem to eagles because of their piscivorous eating habits. Eagles eat mostly freshwater fish like brown bullhead, white sucker, and chain pickerel. When opportunity presents itself, eagles will eat other birds, like black ducks, gulls, cormorants, and eiders, as well as seasonal, migratory fish like alewives.
According to the Biodiversity Research Institute, Maine Bald Eagle nestlings and adults are exposed to elevated levels of methylmercury via the freshwater food web, especially in lake habitats. Mercury is higher in the feathers, eggs, and blood of Maine eagles than in most other comparable populations, and may be affecting reproduction.
According to the Penobscot River Restoration Trust, Maine's Native American tribal members consider the eagle the most revered animal in the animal kingdom, and the decline of the eagle and subsequent recovery have deep cultural significance. The eagle maintained significance to new American citizens, who chose it as the national emblem in 1782, because of its long life and great strength. The Bald Eagle's majesty continues to inspire awe and wonder, no matter how common sightings of this bird may become. Look for them now, as come March many eagles will return to their nesting territories near inland lakes and rivers in Maine and places farther to the north.
This Creature Feature was provided by Catherine Schmitt, a biologist who lives in Bangor.