Morphological description of the alimentary canal and adnexal glands in Amazilia tzacatl, Amazilia saucerottei, Amazilia amabilis and Anthrachotorax nigricollis species.

The hummingbird family (Trochilidae) includes the smallest and most metabolically active vertebrates. They have a high energy demand because of their extraordinarily high metabolic rates during hovering while looking for food. The morphology of the digestive apparatus is related to the feeding habits of the species.