American Bittern

Botaurus lentiginosus

(c) Sandy Selesky
  • ARDEIDAE
  • Herons, Bitterns, Egrets
  • Ciconiiformes
  • Avetoro norteño
  • Butor d'Amérique
Introduction
The American Bittern, a medium-sized heron inhabiting reed beds, is rarely seen because of its remarkable camouflage. However, it makes its presence known with its booming song, which can be heard long distances away, particularly at dawn or dusk in the spring.
Fun Fact

Because the American Bittern can create a resonant tone with little movement of its bill, it is also known as the "stake-driver," "thunder-pumper," and "mire-drum."

Gary Zahm, US Fish & Wildlife Service
Bird Sounds
© Lang Elliot, Nature Sound Studio
Vocalization

The song is a loud, booming "oog-ka-chuk."

Appearance Description
This stocky heron is heavily streaked with tan, brown, and white over its entire body. Darker wings and flight feathers, a black face, and neck streaks accentuate the plumage. Males and females have similar plumage. The bittern has a 3 foot wingspan, and is approximately 2.5 feet long from the tip of its long pointed bill to the end of its tail. While the bird appears quite large, it weighs only about a pound.
Range Map
Courtesy Kenn Kaufman
Range Distribution
The American Bittern breeds in wetlands across much of Canada and the northern half of the United States. It winters in the southern United States, Mexico, and the Caribbean.
 
A legend for the range map to the right can be found here.
Habitat
The American Bittern inhabits large, reedy wetlands, and needs shallow freshwater marshes for nesting. In the winter, it may also use brackish coastal marshes. Its camouflage, an adaptation for life in the marsh, makes the bird extremely difficult to see as it stalks through the reeds and cattails. When alarmed, the American Bittern may flush and fly away, or it may freeze with its head, neck, and bill pointing straight up, blending in perfectly with its reedy background.
Feeding
The bittern finds its preferred diet in marshes—aquatic fauna ranging from fish and eels to insects, crabs, and snakes. The bird hunts by remaining perfectly still at water's edge, waiting for its prey, which it captures in a rapid spearing motion. It may also stalk prey with great patience. It is usually most active at dusk and dawn.
Reproduction
American Bitterns are sometimes polygynous, with one male mating with several females. While the nesting habits of the species are not well known, it seems that the female does most of the nest-building, incubation, and chick rearing. The nest is a platform structure of reeds and grasses, upon which 3 to 5 eggs are laid, then incubated for at least 24 days. The young may leave the nest after only a week or two, but they remain close by for another month or longer, until they are able to fly.
Migration
Breeding area covers most of the Canadian provinces and the northern half of the contiguous United States. Winters along most of the Pacific and Atlantic (from New Jersey south) coasts of the United States, south to Cuba and throughout most of Mexico to Central America.
CBC Graph
Graph Legend
Annual Population Indices
  • 3,000,000
  • 3,000,000
  • 7.3 million 40 years ago
  • 59 percent in 40 years
  • Moderate population declines
Population Status Trends
While a population of just under 3 million individuals sounds large, the American Bittern's range is vast. This bird exists in low density and is declining significantly throughout it range. 
  
An explanation of the Annual Population Indices graph displayed to the right can be found here.
Conservation Issues
The Canadian population of the American Bittern appears to be stable. However, in the United States, the situation is very different. The decline of this species may have started as early as the 1890s in some states. Many of the large expanses of shallow marsh that the bittern requires have been lost. A significant portion of the wetlands that remain have been degraded, impacting food resources, nest sites, and in some cases, the bird itself. Agricultural pesticides, acid rain, and silt are probably the main contaminants of these wetlands. The preservation of large, healthy, freshwater marshes is essential to the conservation of this species. Such wetlands must be maintained in both the bird's summer and the winter ranges. In addition, the secretive American Bittern needs to be better studied. Much is still unknown about its biology and behavior.
What You Can Do
  • Protect the Boreal Forest
    Promote conservation of the Canadian boreal forest by supporting the Boreal Songbird Initiative that works to save Canadian boreal habitat for all birds, specifically by fighting inappropriate logging, mining, and drilling, and by promoting the designation of protected areas.

  • Preserve Farmlands
    Promote strong conservation provisions in the federal farm bill, especially the Conservation Reserve Program (CRP), which pays farmers to keep marginal farmlands idle and supports millions of acres of good bird habitat. Contact your county’s office of the Natural Resources Conservation Service (NRCS) or Farm Service Agency (FSA) to find out how to increase the number of acres devoted to helping birds dependent on farmlands.

  • Conserve Wetlands
    Support wetlands conservation programs such as the Clean Water Act, North American Wetlands Conservation Act (NAWCA), and Farm Bill conservation programs such as the Wetlands Reserve Program (WRP), and “swampbuster” (the rule that restricts wetlands from being converted to agriculture). Encourage governments at all levels to enact and enforce wetlands protection and water quality laws and regulations.
More Information
Natural History References
Gibbs, J. P., S. Melvin, and F. A. Reid. 1992. American Bittern (Botaurus lentiginosus). In The Birds of North America, No. 18 (A. Poole, P. Stettenheim, and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, DC: The American Ornithologists' Union.
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
Conservation Status References
Gibbs, J. P., S. Melvin, and F. A. Reid. 1992. American Bittern (Botaurus lentiginosus). In The Birds of North America, No. 18 (A. Poole, P. Stettenheim, and F. Gill, Eds.). Philadelphia: The Academy of Natural Sciences; Washington, DC: The American Ornithologists' Union.
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.