CONTACT NAME/AFFILIATION/MAILING ADDRESS:

Gary Huschle, U.S. Fish and Wildlife Service
Agassiz National Wildlife Refuge, Rt. 1 Box 74, Middle River, MN.
56737

PRINCIPAL INVESTIGATOR NAME/AFFILIATION/MAILING ADDRESS:

Dr. John Toepfer, Private Research Consultant

SPECIES/GROUP:
Region 3 Grassland Birds

STUDY AREA: 
Minnesota, Wisconsin, Michigan, Louisiana, Florida, Mississippi

RESEARCH OBJECTIVE:

1. Determine fall/spring migration routes and migration/wintering habitat of American bitterns.
2. Determine dispersal pattern of juvenile American bittern.
3. Answer deficiencies identified by Partners in Flight for the American bittern in Physiographic Area 40, northern tall grass prairie.
4. Integrate migration and dispersal biology aspects of this study with the Eyes on Wildlife curriculum.

The American bittern, a widely distributed wading bird in North America is undergoing a nation wide decline. The greatest declines, 48% in over 20 years , occurred in the Midwest and north central states. Ignorance of this birds' life history serves to enhance its decline. The American bittern's position in the food chain place it at several trophic levels where it is exposed to pollutants and contaminants. The unusual pumping call during the breeding season may make it one of the easiest of the secretive marsh and wading birds to census. All of these factors make this bird an ideal bio-indicator of the health of inland and coastal wetland/grassland habitats.

METHODOLOGY:

Five years of study of the life history of the American bittern have been completed at Agassiz National Wildlife Refuge. Capture and radio-marking techniques have been developed. Adult bitterns have exhibited high fidelity to breeding territories, however, no juveniles have been recaptured in subsequent years. Four adult bitterns were equipped with satellite radio collars in the summer of 1998 and have successfully migrated to wintering areas in Louisiana and Florida. This proposal would satellite radio-mark 9 adult bitterns (3 in Minnesota, 3 in Wisconsin, and 3 in Michigan) to document fall and spring migration and wintering areas. Six juveniles will be satellite radio-marked to determine dispersal patterns. A habitat reconnaissance trip will be made in the winter and spring to document habitat types and search for other radio-marked bitterns in the areas. GIS data will be acquired to evaluate availability of habitat in selected areas. Location data from selected adult and juvenile birds will be shared with the Eyes on Wildlife research science curriculum established in northwest Minnesota in 1998. This curriculum was developed by Perham School District and has been accepted by the Minnesota Graduation Standards. The curriculum is being made available to other schools in northwest Minnesota and in Wisconsin and Michigan.

EXPECTED RESULTS/PRODUCTS:

The project will provide descriptions of migration patterns for spring and fall, migration and winter habitat and dispersal patterns. Habitat availability will be evaluated for selected areas. Information gained will lay foundation for identifying management needs.

May 1998

From Gary Huschle – Agassiz National Wildlife Refuge Biologist

What we have planned:

  We have ordered 4 satellite transmitters for American bittern that we will put on previously radioed birds in late July or August.  Microwave has not promised that they will be able to fill the order by July 15 so it may get put off 1 year.  This is experimental in collar design, transmission sequence, and location success.  Our objective is to determine migration timing, route and wintering area.  Two birds from Agassiz and two from central Wisconsin would be tagged.  The transmission sequence this year will be once every 10 days in July and August, once every third day in September through November, once every 10 days during the winter, and once every 4 days in April and May.  Based on this year's results and finding money, modifications will be made and intend to tag additional birds next year.  This would include birds from a new study site near Lac qui Parle WMA and possibly in the state of Michigan.  Juvenile birds may be tagged in the second year as we have not had any returning juveniles in the four years previous to this.

Due to the small battery on these bird collars only 56 days of transmission are possible.  The satellite time from Argos should only cost $600.00.  The transmitters are $2950.00.  The wolf collars are  designed to last two years.

Gary Huschle

       1938 and 1939 are the American bitterns tagged on Agassiz NW