The Green-crowned Woodnymph (Thalurania fannyi) is a species of hummingbird

Hummingbird

Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...

 in the Trochilidae family. It is found in humid forest and tall second growth from eastern Panama

Panama

Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...

, south through western Colombia

Colombia

Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...

 (incl. Cauca Valley

Cauca River

The Cauca River is a river in Colombia that lies between the Occidental and Central cordilleras. Born in southwestern Colombia near the city of Popayán, it joins the Magdalena River near Pinillos in Bolívar Department, and the combined river eventually flows out into the Caribbean Sea. It has a...

) and Ecuador

Ecuador

Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...

, to far north-western Peru

Peru

Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....

. It includes the taxon

Taxon

|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...

 hypochlora from south-western Ecuador and adjacent Peru as a subspecies

Subspecies

Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

, but it has sometimes been considered a separate species, the Emerald-bellied Woodnymph (Thalurania hypochlora).

Males have a green head and back, and a violet-blue "shoulder", forked tail and belly (underparts entirely green in males of the taxon hypochlora). Females have a green upperparts, blue or green "shoulder", a white-tipped dark blue tail, whitish throat, chest and vent, and dark grey to green belly (underparts entirely whitish in females of the taxon hypochlora).