Lek-mating Long-tailed Manakins (Chiroxiphia linearis) exhibit an unusual pattern of delayed plumage maturation. Each year, males progress through a series of predefinitive plumages before attaining definitive plumage in their fifth calendar year. Female
Doucet, S. M.; McDonald, David; Foster, M. S.; and Clay, R. P. (2007). "Plumage Development and Molt in Long-Tailed Manakins (Chiroxiphia Linearis): Variation According to Sex and Age." Auk 124.1, 29-43.