Introduction to the Skeleton of Hummingbirds (Aves: Apodiformes, Trochilidae) in Functional and Phylogenetic Contexts

Abstract Historically, comparative study of the skeleton of hummingbirds has focused on systematics, emphasizing differences between hummingbirds and other birds and only rarely addressing differences within Trochilidae. This monograph covers both approaches, and comparisons within Trochilidae are framed within recently published, plausible phylogenetic hypotheses. The data are derived mainly from museum collections of anatomical specimens, covering ~256 species of 102 genera of hummingbirds, and 11 genera of other Apodiformes. Although the syringeal skeleton is included, emphasis is on the axial and appendicular skeletons. The first section deals with the syrinx and with skeletal features mainly associated with nectarivory and hovering, emphasizing characters that are unique to hummingbirds within Apodiformes. The syrinx of hummingbirds lies in the neck rather than the thorax and displays a unique bony knob on the surface of the tympanic membrane. During posthatching development, the upper jaw of humming...