"Stabilisation is also the reason for a Woodpigeon or Pheasant nodding its head, throwing it forwards and then keeping it steady while the body moves forwards. Anyone who has tried to train binoculars on birds from a heaving ship's deck will appreciate the need for a steady platform. The most graphic demonstration that l have seen of a bird's ability to stabilise its head was at a bird-ringing session on the shores of the Wash. An Oystercatcher was being held in readiness for ringing. The handler rotated its body and the wader's head remained the right way up and rock-steady."