The Blue-tailed Emerald, Chlorostilbon mellisugus, is a 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...

 found in tropical and subtropical South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 east of the Andes

Andes

The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

 from 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...

 east to the Guianas and Trinidad

Trinidad

Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...

, and south to northern Bolivia

Bolivia

Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...

 and central Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

.

The taxonomy

Taxonomy

Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 is highly complex and it often includes C. canivetii, C. auriceps, C. forficatus, C. assimilis, C. gibsoni and C. melanorhynchus from north-western South America and Central America

Central America

Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

 as 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...

.

It is a bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 of savanna, scrub, cultivation and similar semi-open woodland. In the Amazon

Amazon Basin

The Amazon Basin is the part of South America drained by the Amazon River and its tributaries that drains an area of about , or roughly 40 percent of South America. The basin is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Venezuela...

, where generally uncommon and more localized than in the northern part of its range, it mainly occurs at forest edge and in várzea

Freshwater swamp forest

Freshwater swamp forests, or flooded forests, are forests which are inundated with freshwater, either permanently or seasonally. They normally occur along the lower reaches of rivers and around freshwater lakes...

. The female lays her eggs in a small cup nest, similar to that of the Ruby-topaz Hummingbird

Ruby-topaz Hummingbird

The Ruby-topaz Hummingbird , commonly referred to simply as the Ruby Topaz, is a small bird that breeds in the Lesser Antilles and tropical northern South America from Colombia, Venezuela and the Guyanas, south to central Brazil and northern Bolivia; also from Colombia into southern Panama. It is...

, placed on a horizontal tree branch. Incubation is 13 days with a further 18 days to fledging.

The Blue-tailed Emerald is 7.5 cm (3 in) long and weighs 2.6 g. The black bill is relatively short and straight. The male has a brilliant green plumage, with white thighs and a dark metallic blue tail (clearly forked in the northern part of its range; slightly so in the central and southern part). The female average smaller than the male and also differ by the grey-white underparts, a blackish ear patch, a short white supercilium/post-ocular streak and white-tipped outer tail feathers.

Blue-tailed Emeralds feed on insect

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s and nectar. The song is a pleasant twittering, and the call of this species is a pebbly tsip.