Great Blue Heron (Ardea herodias)
Squawk Call: A short, loud, and abrupt squawk, often given when disturbed.
Great Blue Heron Squawk Call, August 2, 2009, Vernon Marsh, Waukesha County, Wisconsin.
Croak Call: A low, grating croak, given in a series, usually during aggressive interactions (Stokes 1989).
Great Blue Heron Croak Call, July 3, 2010, Vernon Marsh, Waukesha County, Wisconsin.
Stokes, Donald W., and Lillian Q. Stokes. 1989. A Guide to Bird Behavior Volume III. Little, Brown and Company. Boston and Toronto.