A study was made of the trumpeter swans of the Jackson Hole area including a survey of numbers present, ratios of young to adults, and their behavior. A detailed report is not available at this time. Project Number 149.
Sladen, William J. L.
"Population Dynamics and Social Behvaior of Swans,"
Jackson Hole Research Station Annual Report: Vol. 1967
, Article 13.
Available at: http://repository.uwyo.edu/jhrs_reports/vol1967/iss1/13