Monotypic. Plumage varies, with male's breeding plumage being primary and non-breeding being a relatively temporary "eclipse" in mid-late summer and early fall. Female plumage differs slightly, but per DU similar. M/F differ, especially in breeding plumage. In eclipse males look closer, but not exactly like, females. I was thrilled to encounter a bevy of lifers on my last big outing before the birth of my daughter -- including both REDH and CANV -- two nemesis species!