Mini-macaws are a loosely defined group of small-to-medium-sized macaw species within the tribe Arini. The term has no fixed taxonomic meaning and is principally used in aviculture to describe a small macaw belonging to one of a number of different genera, with overall length being the sole criterion for inclusion. Any macaw with an overall length (including the tail) of less than about 50 cm (20 inches) can be described as a "mini-macaw". Additionally, the "mini-" prefix may be added to the species name when describing the bird in question (e.g. "red-shouldered mini-macaw").