Unmated female white-crown. Mate, on territory. Mated female next territory. Note that some meanings are actually deleterious, but net result is advantageous or the display would not have evolved. Another way to look at signals is how variable they are.
Signals are often Stereotyped.
War of attrition. For example, giving a threat display, you don't want to give away intentions. I want to spend a few minutes discussing why most signals are honest and then look at some exceptions to see what they can tell us about the evolution of communication. This was one of the first things we discussed in this course - good of the species arguments and individual fitness and advocated by George C. Williams. He argued that even the losers of these ritualized contests might come out ahead because they could avoid paying extreme costs.