Date of this Version
United States Fish & Wildlife Service, Region 6 Denver, Colorado.
American Bitterns are medium-sized, brown herons which inhabit large wetlands with dense emergent vegetation. Their cryptic coloration allows them to blend in well with dead emergent vegetation, and American Bitterns have a tendency to “freeze” with the bill pointing up if they feel threatened.
They breed from Newfoundland west to British Columbia (generally south of 55 °N latitude) and south to California, northern New Mexico, and northeastern North Carolina. American Bitterns generally winter in areas where the average temperature remains above freezing. Their winter distribution stretches from Maryland (rarely New Jersey) south to Florida, west to California, south through Mexico to (rarely) Panama.
Due to their secretive habitats, no population estimates are available. Within Region 6, American Bitterns are listed as a Level I / Tier I species (i.e., a species in greatest conservation need) in North Dakota and Utah. They are listed as a Level II / Tier II species (i.e. a species in need of conservation) in Montana, Wyoming, and Kansas.