Some aspects of communication during monocular and binocular looking by dominant jays at subordinate cage mates were studied. The probability that each type of looking was followed by attack in the sender was measured in standardized external situations. The signal value of the various signal situations for recipients was measured by determining the probability that they reacted with retreat during signalling. It was found that the higher the likelihood that a signal situation was followed by overt aggression in the sender, the more a recipient reacted with overt escape.