Table 6 Definitions of seven behaviors observed in wintering whooper swans at Sanmenxia Wetland in western Henan Province, China⁶¹.

Vigilance

With a head-up posture, scanning or staring at the surrounding environment (looking at the source of strong interference); occasionally rotating the head

Fighting

Chasing, spreading wings, and biting

Preening

Using the beak to tidy up feathers around the body, flapping and spreading wings, rolling in water to bath, and cleaning the feet, etc.

Resting

Standing still or taking a rest. When resting, the head usually turns back, and the front end of the beak hides underneath the wings. Occasionally raising the head when alerted, then continuing to rest

Calling

Giving ‘hour’ or ‘ho-ho’ like calls

Locomotion

Including flying, swimming in water, and walking on land or ice

Foraging

Including foraging on land, filtering food with the beak on the water surface, and searching for food underwater