Vegetative Characteristics and Waterfowl Usage of a Montana Water Area

Abstract

During the summers of 1956 and 1959, a study was conducted to determine changes in characteristics of vegetation and waterfowl usage of a pond area in Teton County, Montana. Aquatic vegetation increased on the area during that time, with growth in sago pondweed (Potamogeton pectinatus), stonewort (Chara vulgaris), and alkali bulrush (Scirpus paludosus) the most significant. Changes in portions of the terrestrial vegetation were noted; one such change was accompanied by an increase in nesting. Total numbers of waterfowl and number of species and nests increased during the study period. An apparent decrease in brood usage may have been the result of the difficulty of observing waterfowl in denser vegetation during the second year. A 296-acre pond and surrounding vegetation on the northern edge of Freezeout Lake (also known as Greenfield Lake) in Teton County, Montana, were studied to determine effects on waterfowl usage of vegetational changes resulting mainly from fluctuating water levels. Information was gathered from June 15 to October 15, 1956, and from June 10 to September 24, 1959. The writer wishes to express appreciation to the following: Don C. Quimby, Professor of Wildlife Management, Montana State College, for direction of the study and aid in preparation of the manuscript; W. E. Booth, Curator of the Herbarium at Montana State College, for verification of plant identification; Robert Varner, Gerald Salinas, Dale Witt, Robert Rothweiler, and Robert Eastwood for assistance in the field; and to my wife, Celia, for assistance in the field and aid in processing the data. DESCRIPTION OF THE AREA Freezeout Lake lies at the western edge of the Fairfield Bench in western Montana. It occupies part of a glacial lake basin, surrounded by rolling uplands. The climate is semiarid, and the upland native vegetation is mainly grassland. Soils in the area are cloddy, stratified, silty clays, and clays with subsoils impregnated with alkali (Geiseker 1937). For many years, this lake has furnished good duck hunting. From 1941 to 1952, because of unusual moisture conditions the water area increased from 1,900 to 4,100 acres. Drainage of the area was proposed by local groups. Ellig (1955) studied waterfowl relationships to the area in 1951 and 1952, in cooperation with the Montana Fish and Game Department. In 1953, the Montana Fish and Game Department began to develop the region into a waterfowl management area. A drainage system was constructed, and dikes with water-control structures were planned to divide the area into several water units for management purposes. The study area lies north of the main body of Freezeout Lake and is connected to it by a 0.5-mile canal and a seepage region. Ellig (1955:6) described the area as a 360-acre cattail marsh. In 1953, rising water expanded the pond until it was directly connected to the main lake. The rise of water levels was accompanied by elimination of much of the emergent vegetation. Drainage of Freezeout Lake in 1954 reduced the area by approximately one'A joint contribution from Montana State College, Agricultural Experiment Station, Project Manuscript 844, Paper 519, Journal Series, and the Wildlife Restoration Division, Projects W-56D-6 and W-56-D-7, Montana Fish and Game Department.