Eagles are Environmental Indicators
March 13, 2010
High above the sand dunes in West Michigan, a pair of American bald eagles cavort; they dart, dive and swirl through the air at dizzying heights. Suddenly one of them turns on its back and they grasp talons spinning into a daring, cart wheeling free fall toward earth. They unlock talons and flap their powerful wings, flying upward at the last instant before hitting the ground. This, their courtship ritual, will bond the two eagles together for life.
Today, bald eagles are seen around the Great Lakes more andmore often, but in 1978, these magnificent birds were threatened.
Threatened with extinction. Their eggs never hatched since pesticides that lingered in the environment long after they were sprayed to kill insects magnified in Great Lakes food pyramids. The eagle is at the peak of the food pyramid and its favorite food is fish.
This makes the eagle an environmental indicator; a measuring stick of how well the whole ecosystem is faring. Where the ecosystem is healthy, eagles can live and raise their young.
Since DDT was banned in 1972, the nesting eagle population has increased.