Since its diet consists primarily of small fish and frogs, the presence of the majestic great blue heron (Ardea herodias) stalking the shoreline of Eagle Lake provides another indicator of a healthy lake environment. What is even more encouraging is that they breed at Eagle Lake. Great blue herons prefer to nest in colonies, referred to as a heronry (more specific than the term rookery), building loose nests of sticks in trees near lakes and wetlands. Colonies consist of 5 to several hundred nests.

In 2010, Martin and Elizabeth Lee discovered a colony of at least 10 breeding pairs in a secluded marshy region at the north end of the lake (see photographs at left). Nests may contain 2 to 6 chicks, and the local breeding success should ensure great blue herons in our area in the immediate future.