TIMING, DURATION, AND INTENSITY OF MOLT IN BIRDS OF A NEOTROPICAL SAVANNA IN BRAZIL

While researchers have made great progress investigating the molt of temperate-zone birds, few studies have examined the molt of tropical birds. We carried out this study in 2009 and 2010 in the cerrado biome, Distrito Federal, Brazil. On the basis of 334 birds captured with mist nets, we describe the timing, duration, and intensity of the flight-feather molt in eight species. Molt scores indicated the direction of replacement and points where molt series started and ended. The innermost primary usually was the first flight feather to drop, and primaries were replaced proximal to distal. Secondaries were replaced in two series, and S6 or S5 typically was the last remex to complete growth. Rectrices were replaced in a single series on each side, from RI (central) to R6 (lateral). All species replaced their primaries according to the rules followed by most passerines. The White-eared Puffbird (Nystalus chacuru: Galbuliformes) was an exception; it replaced primaries in two molt series and possibly does not molt its secondaries completely every year. In comparison to similar temperate-zone birds, whose molts take 42-105 days, tropical birds seem to have a slower metabolism, with molt having an average duration of 122 days and intensity of 3.1 feathers growing simultaneously. Larger species required more time to molt. In four species we found overlap of molt and breeding.