Waterfowl using Upper and Lower Swan Lake in Grand Teton National Park were censused regularly from 30 June 1969 to 18 August 1969. Differences in numbers and species of ducks using the two connecting lakes were noted. Factors affecting the lakes, sewage pollution, beaver dam location, natural succession and disturbances caused by horses and people were investigated. Although it is impossible to assign one factor as the most important cause of species differences on the two lakes, the relative importance of all influences is estimated. Further fall observation of migrating flocks of common mergansers and subsequent comparison of this point with Huckabee's (1965) data may give some index with which to compare present and past duck populations.
"Waterfowl Populations on Swan Lake,"
Jackson Hole Research Station Annual Report: Vol. 1969
, Article 24.
Available at: http://repository.uwyo.edu/jhrs_reports/vol1969/iss1/24