A pair of bald eagles recently completed construction of a brand new nest at a location not far from where I live. Built from an assortment of sticks and twigs in the crotch of a large poplar tree, the nest, or aerie, is perhaps 4-to-5 feet across and just as deep, and at 60 feet above the ground, it has a commanding view of the surrounding countryside. I’ve been monitoring the nest since I became aware of it several weeks ago and each time I check on it, the eagles are present or nearby, keeping an eye on the place.
Female eagles don’t lay their eggs until mid-to-late March, so why is this pair standing guard over their nest in January? My guess is that it’s to prevent it from being hijacked. Great-horned owls lay their eggs in February – and they don’t build their own nests. They steal them from other raptors and great blue herons, and then remodel them to suit their needs. The great-horned owl is nearly as large as a bald eagle and can be a fierce opponent in a territorial squabble.
Bald eagles can live in the wild for 30 years or more and they mate for life. They return to nest and reproduce in the same general area from where they fledged and will continue to occupy that nesting territory for the rest of their lives. A pair usually produces one or two eaglets per year, and on rare occasion – three. Eagle nests are reused year after year and are sometimes annually enlarged until they collapse from their own weight, in which case the pair will build another nest nearby.
A half-century ago, the bald eagle was placed on the Endangered Species list because chemical contamination weakened its eggshells, causing eggs to be broken by parents during incubation. As a result, the bald eagle population plummeted. In 1976, the year of this nation’s bicentennial, New York became the first state in the country to launch a bald eagle restoration program and in 2007 the eagle was removed from that list as a result of the success of that project. And the pair of eagles guarding the nest not far from where I live is living proof of that success—great-horned owls notwithstanding.