Table 1.

Summary of the potential functions of guenon face pattern coloration and the different predictions each hypothesis makes for the appearance and variability of visual signals within and between species. Adapted from [9].

		predicted appearance
signal function	description	within species	between species
individual identity	recognition and discrimination of familiar individuals	continuous variation on multiple dimensions resulting from negative frequency-dependent selection for rare phenotypes	no prediction
species identity	recognition and discrimination of con- and heterospecifics	consistent appearances resulting from stabilizing selection for phenotypes that match receivers' species recognition templates	continuous variation on multiple dimensions resulting from disruptive selection for unique species appearances that aid discrimination
intraspecific mate selection	identification of potential mates and competitors	discrete variation on a single dimension between age and sex classes	no prediction
quality	determination of the fitness of potential mates and competitors	continuous variation on a single dimension that varies within age and sex classes	no prediction