Wading birds that a feed on shorelines are migratory in Maine. It is rare to see a wading bird in Maine in the winter. They are dependent on open water for fishing of crabs, mollusks and fish. Herons will capture frogs and snakes in fields, which are not available in the winter, either. Great and Snowy egrets were once endangered. Their plumage was highly sought after for making ladies' hats. They are now protected by the Migratory Bird Treaty Act; their populations have successfully rebounded.