We report the discovery of a previously undescribed feeding mechanism
in an avian planktivore, the Red-necked Phalarope (Phalaropus lobatus)
. We employed high-speed video to elucidate the kinematics of prey tra
nsport, and to test hypotheses generated by a model describing prey tr
ansport as a function of surface tension. Prey items are transported i
ndividually from the tip of the beak to the mouth by forces resulting
from the surface tension of water surrounding prey. Experiments conduc
ted with the beak of a dead bird demonstrate that surface tension is s
ufficient to explain prey transport in Red-necked Phalaropes without t
he use of suction or tongue motions. This feeding mechanism may be wid
espread among the shorebirds and represents a potential intermediate s
tep in the evolution of filter feeding in birds.