The Trumpeter Swan Society Restore - Expand - Protect - Advocate - Involve - Rebuild
Trumpeter Swans frequently bob their head and necks up and down (head bobbing). With this motion they also have a variety of vocalizations. This combined activity apparently serves as a form of communication between individuals and within the group. Head bobbing and vocalization activity increase when the birds are disturbed and reaches maximum intensity just prior to the birds taking flight. This behavior may be brief or absent if the birds are suddenly startled and take flight.
Tundra Swans do not bob their head and neck in this manner. Occasionally Tundras will nod only their head up and down. There is no defined preflight display as in the Trumpeter. While vocalizing they may hold their head and neck out at a 45� angle