Trumpeter swans BIG TIME illegal!
Tundra swans I know have a season on the east coast, not sure about the central flyway.
This is a copy/paste from the Wisc. regs:
Don’t Shoot a Swan!
All wild swans are protected species in Wisconsin.
Shooting a swan may cost you up to $2,327 in penalties and three years
revocation of all hunting, fishing, and trapping privileges.