Botaurus lentiginosus
American bittern

Key Characteristics

This brown, medium sized heron is 23 – 33 inches (60 – 85 cm) in length with a stout body and neck and relatively short legs. Adults are dark brown above, heavily streaked brown and white below, with a rusty crown and white throat. A long black patch extends from below the eyes down each side of the neck, which is a character unique among the herons. Previous authors have best described the American bittern’s low, resounding song as a deep, gulping, pounding “BLOONK-Adoonk”, which is repeated one to 10 times in succession and can be heard from as far away as 1/2 mile.

Status and Rank

  • State Status: SC
  • State Rank: S3
  • Global Rank: G5

Occurrences

County NameNumber of OccurrencesYear Last Observed
Alger22009
Arenac12007
Baraga12015
Bay32007
Charlevoix11999
Cheboygan11998
Chippewa112015
Delta22009
Gratiot12003
Houghton12015
Huron22007
Iosco12010
Jackson51996
Kalamazoo11973
Kalkaska12004
Livingston11989
Mackinac42007
Macomb12004
Manistee12005
Marquette12012
Mason12005
Saginaw22003
St. Clair22015
Tuscola22007
Washtenaw11989
Wexford12013
Distribution map for Botaurus lentiginosus

Updated 1/31/2017. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.

Habitat

American bitterns nest and forage in a wide variety of wet to wet-mesic habitats with herbaceous or herbaceous-shrub cover. They are area-dependent and are typically found only in the larger wetlands.

Natural Community Types

Methodology

For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Management

Preservation of freshwater wetlands, especially large shallow wetlands with dense growth of robust emergent vegetation, is the most urgent management need for this species. Programs that provide funds for wetland restoration and protection on private and public lands can effectively conserve habitat for this species and need to continue. Such initiatives include Farm Bill programs like the Wetlands Reserve Program and Conservation Reserve Program, and the North American Waterfowl Management Plan, which uses funding appropriated through the North American Wetlands Conservation Act. Existing wetlands also need to be protected from chemical contamination, siltation, eutrophication, and other forms of pollution that could harm the birds or their prey. Encouraging best management practices, such as filter strips, no-till farming, and conservation tillage, in surrounding watersheds would help protect priority habitats from pollution.

Active Period

Migration from first week of April to fourth week of April

Nesting from first week of May to first week of August

Migration from first week of September to fourth week of October

Survey Methods

Because the American bittern is most often concealed in dense herbaceous wetlands, the best time to survey for this species is during the breeding season when it is more apt to call to mark its territory or advertise for a mate. Singing is most often crepuscular and nocturnal, but American bitterns can be heard throughout the day and night early in the breeding season. Conspecific call-response techniques have been used successfully to improve the effectiveness of surveys for American bitterns and other marsh-nesting birds.

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer [Accessed May 27, 2017]

More Information

See MNFI Species Abstract

References

Survey References

Technical References

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