Each of the two polytypic groups is recognized as a separate species: the group Russet-throated Puffbird (Russet-throated) Hypnelus ruficollis ruficollis Group becomes Russet-throated Puffbird Hypnelus ruficollis; and the group Russet-throated Puffbird (Two-banded) Hypnelus ruficollis bicinctus/stoicus becomes Two-banded Puffbird Hypnelus bicinctus. These groups are srikingly different in plumage and long had been considered to be separate species (e.g., Peters 1948, Phelps and Phelps 1958), but had been lumped on the basis of a population with apparently intermediate plumage. Hybridization appeares to be infrequent, however, and reports of hybridization may be based at least in part on specimens of juveniles (Restall et al. 2006). Vocalizations also differ between the two groups (Donegan et al. 2015).