Flight Feather Molt of Turkey Vultures

Abstract

We document the molt sequence of flight feathers in Turkey Vultures (Cathartes aura) based on studies of captive and wild birds, and examination of museum specimens. We found an unusual pattern of primary replacement, which appears to be a modified form of Staffelmauser, or stepwise wing molt. A Staffelmauser-like strategy for replacement of the secondaries is also described. These patterns of feather replacement appear to be adaptations to maintain flying performance while replacing all primaries and most secondaries during each molt. To what extent molt patterns in Turkey Vultures reflect convergent adaptation for flight, rather than ancestral characters useful for phylogenetic studies, remains unknown.