RT Cont Turnstones flew into the vicinity at the edge of the colony. Within a few minutes 3 of them started working a Sooty tern on an egg. The turnstones moved rapidly about the tern on all sides, the tern lunging at one and the other turn-stones spontaneously running toward the egg. Then a 4th turnstone joined the other 3. The Sooty made some rather vicious lunges and short chases (perhaps a foot) toward one or another of the turnstones. At each lunge or chase one or more