The U.S. Fish and Wildlife Service has a large on-line library with a lot of interesting information about wildlife. Including some neat posters that you can download. I found an beautiful poster about the restoration of Trumpeter Swans.
The Trumpeter Swan has been re-established in Minnesota very successfully. There are an estimated 6,000 Trumpeters in Minnesota as of last winter. We in Crane Lake had a pair of Trumpeters successfully raise 3 young Swans. As far as I know, they are not flying yet, the young ones are still grounded on an area beaver pond.