Watching a hermit thrush forage for food on the floor of a forest, you might notice a strange behavior. The bird will stand still and rapidly shake on of its legs. The behavior is known as “foot-trembling” and it’s used to induce insects to move in order to reveal their location.
Other birds like the Piping Plover and the Ringed Plover also use foot-trembling behavior to scare up prey out of the sand along beaches. Â
Sometimes referred to as “foot-tapping” or “foot-pattering”, the movements help to bring worms and other prey closer to the surface of the sand. Â
There is some debate among researchers as to whether this activity causes the worms to move closer to the surface or if it’s the vibrations from the foot-trembling that move the worms to the surface.
In this video below, you can see a Piping Plover demonstrate foot-trembling by rapidly tapping one leg over the surface of the sand. Â
The Plover alternates tapping its legs as it hunts for worms. Â Periodically, the bird notices movement in the sand and dips its beak into the sand to retrieve the prey.
More:
Osborne, B. C. (1982). Foot-trembling and feeding behaviour in the Ringed Plover Charadrius hiaticula. Bird Study, 29(3), 209-212. DOI: 10.1080/00063658209476759
Simmons, K. E. L. (1961). Foot-movements in plovers and other birds. Brit. Birds, 54(1), 34-39.
