Trumpeter Swans mate for life, but seem to renew their vows each year with a choreographed duet of head bobbing and pair swimming (is that an Olympic event?). Pairing may not occur until birds are more than four years old, and the average first nesting is 6-7 years, but these largest of the waterfowl species live 20-30 years in the wild, so there is plenty of time for producing offspring.
Once the male establishes his overall attractiveness to his mate,
there is a session of synchronized swimming, punctuated by head dips.
Noisy but oh so graceful, the Trumpeter Swan.