abstract: Breeding male Ruffs (Philomachus pugnax) appear to communicate individual identity through extreme variation in coloration and pattern of their plumages. If plumage variation evolved to provide sufficient information to signal individual identity, we might expect different plumage com-ponents to vary independently. We find that varia-tion in four plumage characteristics is largely inde-pendent. Previous studies produced conflicting answers about plumage-component independence, perhaps because they failed to separate two geneti-cally distinct behavioral categories of males, which differ in plumage types, in their analysis. We pro-pose that using plumage variation to signal individ-ual identity, rather than voice (used by most other bird species) was favored by lengthy daytime male display in open habitats in close proximity to receiv-ers. However, signaling associated with the unique dimorphism in this species’ male mating behavior might also have influenced the evolution of extraor-dinary plumage diversity in this species.