Bald Eagle

With the statewide breeding population surpassing 100 pairs for the first time in 2023, it’s hard to believe that as recently as 1987 there were no Bald Eagles nesting in New Hampshire. We’ll probably never know how many eagles the state supported prior to their extirpation by the middle of the 20th century, but they were likely widespread along the shorelines of our many Lakes & Rivers. Populations of our national bird were already in decline long before DDT appeared on the scene, but this pesticide was something of a nail in the coffin built through persecution and habitat loss. Through eating contaminated prey, eagles accumulated enough DDT to impact their reproductive success, largely by causing eggshells to thin. In 1949, a pair nesting at Lake Umbagog was the last in the state for almost 40 years.

DDT was banned in 1972, and as the regional population (especially in Maine) began to rebound, it was only a matter of time before the Bald Eagle returned to breed in New Hampshire. In 1988 a pair returned to the same tree at Umbagog last used in 1949, and the following year they successfully fledged a single chick. This remained the only nest for a decade, but the late 1990s saw the beginning of the steep growth we see today. In fact, the population is currently doubling every 5-10 years and shows no sign of slowing down. A similar trend has been playing out with the state’s winter population. There were always a few eagles on Great Bay or the major rivers even when none were nesting, and their roosting sites were carefully protected and monitored to minimize disturbance. Now they are a common sight wherever there is open water, and many pairs remain on their nesting territories year round.

Bald Eagles are opportunistic foragers, feeding on carrion as well as prey they kill themselves. The latter are primarily fish, waterfowl, and other water birds like gulls. Most are captured from the air, during which a flying eagle suddenly stoops upon a target to grab it with its talons. The species opportunism extends to aerial piracy, in which the eagle will harass another bird – such as an osprey, heron, or another eagle – to force it to release its catch.