Re-Establishing Bald Eagle and Osprey Breeding Populations in South Dakota Through Hacking: A Feasibility Study

Bald eagles (Haliaeetus leucocephalus) and ospreys (Pandion haliaetus) historically nested in South Dakota, but until 1991 neither species had nested in the state for > 100 years. In 1991, an osprey pair nested in the Black Hills near Pactola Reservoir, and in 1993, a bald eagle pair nested along the Missouri River on the Karl Mundt NWR. During 1991-93, I conducted a study to determine the feasibility of hacking as a means to re-establish sustainable breeding populations of bald eagles and/or ospreys along major rivers, lakes, and reservoirs in South Dakota. Methods used in this study were descriptive in nature due to the large scale of the study, variation in habitat types, and the amount of information available for each habitat assessed. Hacking feasibility and whether or not a hacking program was warranted were determined by (1) assessing the nesting suitability of river, lake, and reservoir habitats for bald eagles and ospreys, (2) assessing the likelihood of natural expansion into suitable habitats by breeding bald eagles and ospreys, and (3) estimating bald eagle and osprey hacking program costs. Nesting suitability of river, lake, and reservoir habitats was assessed based on the number and abundance of potential forage species, foraging habitat and nesting substrate quality, and the amount of human activity. Aerial and ground surveys, aerial photographs, the literature, and interviews with wildlife and fisheries personnel were used in assessments. Nesting habitat suitability was assessed on a regional basis to account for the dispersal distances of bald eagles and ospreys. Results from this study indicated that bald eagle and osprey nesting habitat near rivers, lakes, and reservoirs within South Dakota was limited. Absent or inadequate nesting substrate, poor foraging habitat quality, unpredictable forage fish populations, high human activity, and potential contamination problems were factors that negatively influenced bald eagle and osprey nesting habitat suitability. Suitable bald eagle nesting habitat occurred along the unchannelized Missouri River in southeastern South Dakota below Fort Randall and Gavins Point Dams. However, a bald eagle hacking program in this area was considered unwarranted because bald eagles will likely occupy suitable nesting habitat through natural expansion in the near future. Hacking ospreys in conjunction with an artificial nesting structure program was considered feasible along reservoirs in the Black Hills, lakes with semi-permanent and permanent fisheries in Day, Marshall, and Roberts counties, Lewis and Clark Reservoir, and along the unchannelized Missouri River below Fort Randall and Gavins Point Dams. However, an osprey hacking program was considered unwarranted in the Black Hills due to the likelihood that ospreys will occupy suitable habitat through natural expansion in the near future. Results indicated that the Missouri River in southeastern South Dakota including the unchannelized reaches below Fort Randall and Gavins Point Dams and Lewis and Clark Reservoir was the best location to target for an osprey hacking program. Suitable nesting habitat was most abundant along the Missouri River, and ospreys historically nested near the Missouri River in Clay county. Furthermore, ospreys are not expected to occupy suitable nesting habitat along the lower Missouri River in South Dakota through natural expansion in the near future.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis - University Access Only

Discipline thesis:degree_discipline

Wildlife and Fisheries Science

Year

1994

Author dc:creator

• Usgaard, Robert E.

Contributors dc:contributor

• Kenneth F. Higgins

• Natural Resources and Conservation

Statement dc:rights

• Copyright © 1994 Robert E. Usgaard. All rights reserved.

Language dc:language

en

Repository record dc:identifier

https://openprairie.sdstate.edu/etd/584

OAI identifier oai:identifier

oai:openprairie.sdstate.edu:etd-1584