title: The 'foremost ornithological mystery of Costa Rica':Amazilia alfaroanaUnderwood, 1896.
abstract: The hummingbird Amazilia alfaroana is known from a single specimen, collected on the Volcán de Miravalles, in north-west Costa Rica, in September 1895. Since the early 20th century, the taxon has been almost always been treated as a subspecies of Indigo-capped Hummingbird A. cyanifrons, which is otherwise endemic to Colombia, although it has also been tentatively suggested that the holotype might represent a hybrid between two unnamed species of trochilids. Our detailed analysis of the specimen reveals species-level differences between A. alfaroana and A. cyanifrons, and no evidence of characters that might suggest a hybrid between two species known to occur in the relevant region. Until molecular techniques have been brought to bear, we believe that A. alfaroana is best treated as a possibly now extinct species.
authors.affiliation: Field Museum of Natural History, 1400 South Lakeshore Drive, Chicago, IL 60605, USA.. GMKirwan@aol.com.
authors.forename: Guy M
authors.initials: GM
authors.lastname: Kirwan
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Collar
mesh_terms: D000825:Animal Structures / Q000033:anatomy & histology / Q000254:growth & development; D000818:Animals; D001717:Birds / Q000033:anatomy & histology / Q000145:classification* / Q000254:growth & development; D049628:Body Size; D003364:Costa Rica; D017753:Ecosystem; D005260:Female; D008297:Male; D009929:Organ Size
keywords: Aves, Trochilidae, Costa Rica, Amazilia alfaroana, Volcán de Miravalles