Pair formation - Trumpeter swans most often form pair bonds when they are 2 or 3 years old, and first nest when they are 4 or 5 years old.
Cygnets remain with their parents throughout their first winter.
They separate from their parents the following spring, but siblings may remain together into their third year. Molt - Nonbreeding subadults molt first. Most nonbreeders in Alaska begin their molt in late June or early July. It is rare for both members of a breeding pair to be flightless at the same time. The male of the pair usually molts first.