I studied the lek organization and courtship displays of the Orange-crowned Manakin (Heterocercus aurantiivertex) in undisturbed, lowland rain forest in northeastern Peru. The majority of leks were in seasonally flooded or swampy forest, and most were situated around the borders of old ox-bow lakes. Males maintain loosely packed courts inside exploded leks or “quasi leks,” which may extend for more than 1 km. Within leks, males vocalize throughout the day and occasionally perform two distinctly different solitary displays. One is a spectacular aerial performance that begins above the canopy. The “log display” is performed just above ground- or water-level and consists of a series of short, ritualized jumps.