The guanacaste hummingbird or Alfero's hummingbird[1] (Amazilia alfaroana) is a possibly extinct species of hummingbird known only from a holotype collected in 1895 at the Miravalles Volcano in Costa Rica.
It is usually treated as a subspecies of the Indigo-capped hummingbird or a hybrid between two unknown hummingbird species, but analysis of the holotype suggests it is its own species.[2]
It is possibly extinct, but the ecological stability of the area where the specimen was found indicates a possible undiscovered population still existing.[3] The IUCN classifies it as critically endangered.