Many marsh birds like the American Bittern and the Great Blue Heron have songs which are low and harsh. Members of the crow family, like the Common Raven, Black-billed Magpie, and American Crow, also have low harsh voices. Perhaps the non-directional quality of low-pitched sounds are advantageous in marshes where There are many high-pitched insect and amphibian sounds, as well as predators. Do we know why crows caw? Quoth the raven: "Nevermore".
There are 12 birds you can easily hear and identify who have Croaks and Squawks. The following is a list, in American Ornithologists' Union order, of these birds: