Interior Population Trumpeter Swan Migration Ecology and Conservation

Photo Credit: Beau Liddell

Trumpeter swans currently breed throughout most of the western Great Lakes region, including in Minnesota, Wisconsin, Michigan, Iowa, Manitoba, Ontario, and Ohio. However, beyond estimates of population size and trend and distribution, there is relatively little recent information about their ecology, hindering conservation decision-making. To address current information needs, we are marking a sample of Interior Population trumpeter swans with GPS-GSM transmitters. These transmitters record high-resolution, high frequency location and related data and transmit those data through cellular phone networks.

Objectives

This project started in Minnesota, where the bulk of the Interior Population of trumpeter swans breeds. Initial funding was provided by the Minnesota Environmental and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR) and focused on the following research objectives:

• Evaluate year-round swan movements, including determining the locations where swans spend the winter, and the timing and duration of their movements.
• Determine whether and where trumpeter swans make molt migrations.
• Evaluate year-round habitat use and selection patterns of trumpeter swans.
• Estimate annual survival rates of trumpeter swans, if sample sizes are adequate and fates (i.e., mortality events) can be determined.

Additional funding sources and collaborations with additional project partners have allowed us to expand the scope of the project to include the following research objectives:

• Quantify extent of gene flow among Interior Population trumpeter swans, their overall genetic diversity, and genetic differentiation from source populations.
• Evaluate the association between migratory behavior and genetic divergence of different groups of trumpeter swans.
• Quantify concentrations of lead in Interior Population trumpeter swans and assess potential sub-lethal effects of lead exposure on migration and annual movements.

Results of this study will inform current and future Interior Population trumpeter swan conservation by providing basic information about migration, year-round movements, mortality risks, and use of agricultural and other landscapes. As part of this project, location data will be archived and made available to the public via a website that summarizes trumpeter swan movements and habitat use. Thus, the project will also offer the opportunity to actively engage and inform the general public about how their past investment in conservation made a positive difference to the region’s natural heritage today.

Key Concepts

• Interior Population trumpeter swans have increased dramatically in abundance and distribution, well beyond original population objectives when they were re-established starting in the 1960s.
• Currently, there is a lack of region-specific information on their ecology, including about seasonal movements and habitat use.
• Our project will provide information to help guide conservation as trumpeter swans continue to transition from a rare to a common part of the biological community in the western Great Lakes region.

Contact Information

David E. Andersen, U.S. Geological Survey, MN Cooperative Fish and Wildlife Research Unit, University of Minnesota: 612 626-1222, dea@umn.edu

John Fieberg, Associate Professor, Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota: 612 301-7132, jfieberg@umn.edu

David Wolfson, PhD Student, University of Minnesota: 574 360-9723, wolfs064@umn.edu