Agassiz National Wildlife Refuge staff, request that sightings of American bitterns on National Wildlife Refuges, State Conservation locations, and private lands be reported to their office to help in researching the birds migration patterns. American bitterns, also known as Slough Pumpers, were wing-tagged at the Middle River, Minnesota refuge to aid in this effort.
The American bittern is a stocky bird with brown streaking underneath and a sometimes-visible black streak extending down from the base of the bill. They are solitary feeders -- standing or walking very slowly, then striking prey with a lightning stab. Their diet includes fish, reptiles, amphibians, insects and small mammals.
Until recently, the American bittern has been a common marsh bird. Populations are currently declining. Habitat loss, human disturbance, pesticides and contaminants are believed to be the main threats to populations.
The secretive nature of the bittern makes it difficult to locate and observe when it is not vocalizing. During breeding, males give a booming "pumper-lunk" call, sounding like an old-fashioned hand pump. The past two field seasons, American bitterns have been radio-tagged at Agassiz National Wildlife Refuge by refuge staff and partners including Dr. John Toepfer of St. Cloud State University, Minnesota, and members of North Dakota State University, to determine habitat use and movement around the refuge. Researchers are interested in going a step further and finding out about dispersal and migration.
In the 1995 and 1996 field seasons, bitterns were also tagged with plastic wing markers. This enables people in the field to identify the bird and report on its whereabouts. Anyone sighting a marked American bittern is urged to call refuge staff at (218) 449-4115 and report where it was sighted, the date, tag color, tag number if possible, and the bitterns activity at the time of the sighting.
The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 93-million-acre National Wildlife Refuge System which encompasses more than 530 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 66 national fish hatcheries, 64 fishery resource offices and 78 ecological services field stations. The agency enforces Federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign governments with their conservation efforts. It also oversees the Federal Aid program that distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies. For further information about the programs and activities of the U.S. Fish and Wildlife Service in the Great Lakes-Big Rivers Region, please visit our home page at: http://midwest.fws.gov
