“I was watching some plovers today and was delighted to be able to document the ‘foot-trembling’ feeding method of the Little Ringed Plover (Charadrius dubius curonicus).
“This feeding method has been described in this species since 1915 and also in a number of other shore birds (Simmons 1961). Many other foot movements associated with feeding in shore birds are also recognised (Simmons 1961, Sparks1961).
“’Foot-trembling’ is described as the rapid shaking of one leg at a time. Some authors sub-divide foot-trembling into two types, ‘foot-tapping’ – where the foot clearly hits the surface, and ‘leg-shaking’ – where the foot does not touch the surface (Simmons 1961, Armitage 2008).
“It is suggested that foot-trembling assists a bird to identify prey located below the surface or dislodge concealed prey.
“Please see the YouTube video recording of this activity, made using the Nikon Coolpix P900. It is a compilation of a number of recordings taken this morning.
“My observations were of two birds that were foraging together and may be a pair (no competition or aggression noted). Foot-trembling was used extensively for feeding and almost continually for long periods. Immediately after getting a prey the birds would dart forwards to a new site. When stopping the birds would assume a characteristic posture, standing on one leg and ‘foot-trembling’ the other. Either foot was used but there seemed to be a preference for the right foot (longer visual observations). A rapid oscillation is done, and literature suggests this is at a rate of 10 shakes per second (Osborne 1982). The ‘foot-trembling’ episodes usually last between 2-7 seconds, but occasionally much longer if there is no result (see one at the end of the recording). Usually the ‘foot-tapping’ style is used, where the foot is raised and hits the surface. Occasionally the ‘leg-shaking’ style is used, where the foot does not leave the surface but still creates a vibration.
“Prey is taken by beak probing in the mud. I noticed that often the prey that is taken is located about half to one length of the bird away (tip of beak to tip of tail distance).
“The two still images posted here show the characteristic leg posture and vibration in the water/mud.”
Useful Reference (all available online):
Simmons, K.E.L. (1961). Foot-movements in plovers and other birds. British Birds, 54: 34-39.
Sparks, J.H. (1961). The relationship between foot-movements and feeding in shore birds. British Birds, 54:337-340.
Armitage, I. (2008). Foot-trembling and beak probing by the shore plover (Thinornis ovaeseelandiae) on sandy beaches. Notornis, Vol. 55: 38-39.
Osborne, B.C. (1982). Foot-trembling and feeding behaviour in the Ringed Plover Charadrius hiaticula, Bird Study, 29:3, 209-212.
Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
17th October 2015
Location: Malim Nawar Wetlands, Perak, Malaysia
Habitat: Extensive ex-tin mining area with extensive pond/lakes, wetlands, fish farming