Snowy and cattle egrets nested in Pennsylvania during the 1970s and '80s. Their colony on the Susquehanna River's Rookery Island in Lancaster County was abandoned in 1988. Wading birds are part of the complex web of life in the marshes and along the water's edge. When several species of herons inhabit a waterway, lake or swamp, specialized feeding patterns often develop. The great blue heron usually wades in deeper water, looking for large fish.
Common egrets hunt the slightly smaller fish found closer to shore.
Although mainly predators, herons are also prey for some species, including foxes, minks, hawks and especially raccoons. Crows and tree-climbing snakes may rob unguarded nests. Few predators dare tackle an adult heron, especially one of the larger species. At one time herons were slaughtered for their plumage, which was used to decorate women's hats, but today they have little to fear from humans. They're protected by federal and state laws.