Jessop B. Low

Waterfowl Use of Uinta Mountain Wetlands in Utah

Waterfowl use was recorded in 1965 and 1966 at different elevations of the Uinta Mountains, Utah, from spring thaw until fall freeze-up. Sixteen species were observed; mallard (Anas platyrhynchos), green-winged teal (A. crecca), pintail (A. acuta), and ring-necked duck (Aythya collaris) were the most abundant. Ninety-eight percent of the observed waterfowl were below 3,000 m. Waterfowl numbers were highest during migratory periods and lowest in the breeding season. Adult waterfowl were seen most often on natural catchment basins and beaver (Castor canadensis) ponds larger than 0.4 ha. Low-elevation wetlands ( 2,900 m) had little waterfowl food. Utilization of high mountain wetlands by spring migrants and breeders was dependent upon ice melt, whereas freeze-up did not seriously affect fall use. J. WILDL. MANAGE. 41(1):172-117 Few intensive studies are available on the ecology of waterfowl in mountainous areas, and early mountain explorers wrote only brief notes on waterfowl observations at high elevations. Frary (1954) conducted a waterfowl production study on the White River Plateau in Colorado, and Rutherford and Hays (Unpublished data) investigated waterfowl breeding in the mountains surrounding the San Luis Valley, Colorado. Mallard, green-winged teal, and shoveler (Anas clypeata) were noted by Pattie and Verbeek (1966) on Beartooth Plateau, Montana. Several studies on waterfowl use and productivity of wetlands below 1,800 m have been conducted in Utah, but none has been made on the extent to which waterfowl use high mountain wetlands in Utah, nor on the contribution they made to the waterfowl resources of that state. Objectives of this study were to investigate species composition and seasonal changes in abundance of waterfowl in a high mountain area; define the types, distribution, and use of different wetlands; and estimate waterfowl production in a high mountain habitat. We thank the personnel of the Utah State Division of Wildlife Resources and the U.S. Fish and Wildlife Service for their financial support of this study, the U.S. Forest Service and Soil Conservation Service personnel for their valuable assistance, and the many recreationists who reported waterfowl observations.

Waterfowl Accidentally Caught in Muskrat Traps

During a study of muskrats on the stateowned Locomotive Springs Refuge in western Box Elder County, Utah, opportunity was afforded to study the relative effects on ducks of muskrat trapping at different seasons. For many years, trapping of muskrats was done in both fall and spring. Recently the trapping season has been in the spring from February 15 to April 1. Many trappers claim fall and early winter trapping to be more advantageous to them than spring trapping. Wildlife administrators have been concerned about the number of ducks which are caught and killed in muskrat traps. The importance of this type of mortality has not been previously recorded for Utah. Gashwiler (1949. The effects of spring muskrat trapping on waterfowl in Maine. Jour. Wildl. Mgt., 13: 183-188.) calculated that 4165 ducks were caught in spring trapping during the 1946 Maine season. He concluded that waterfowl trapping was a serious concern to the black duck. In mid-winter trapping in Utah, December 26, 1950 to February 11, 1951, done on an experimental basis by one trapper under special permit, 38 ducks and 1 coot were caught while trapping 166 muskrats. This represents one duck per 4.21 muskrats taken. Maine figures were one duck per 14.7 and 17.7 muskrats respectively for the 1946 and 1947 seasons (Gashwiler, op. cit.). A census of waterfowl on the Refuge, January 10-11, 1951, gave a total of 1085 wintering ducks. On this basis, 3.5 percent of the total wintering population had been caught in muskrat traps. Muskrat trapping was concentrated in open water near springs and along streams leading from springs to shallow frozen lakes. Ducks also frequented the open water of the springs. Because trapping was done largely along streams, traps with drowning rigs were predominantly used. Use of these drowning sets resulted in 69.3 percent of the captured ducks being killed by drowning. Maine studies howed that 47 percent of ducks caught in muskrat traps were drowned. The species composition of the trapped ducks followed the relative abundance of those species in the wintering population. The mallard was predominant in the wintering population, constituting 63.2 percent of the total ducks; the pintail was next, comprising 21.0 percent; followed next by the green-winged teal with 13.2 percent; and.the shoveller with 2.6 percent. In the regular trapping season, February 15 to April 1, 1951, two other trappers in the widespread marshes caught 788 muskrats and 8 ducks or about 98 muskrats to each duck