American bittern is also part of the same PA environmental ed package as Indiana myotis. It has suffered greatly from the loss of wetland habitat, especially in southeastern PA, where many marshes once used by breeding bitterns have been filled for development or choked by sedimentation. This species was listed as a threatened species from 1979 until 1997, when it was downgraded to endangered. It is an uncommon to rare regular migrant in most of Pennsylvania, and is endangered because of its dependency on specialized marshes; wetlands have declined by more than 50% in PA over the past two centuries.