The garden emerald (''Chlorostilbon assimilis'') is a small

hummingbird Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics aro ...

in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is found in

Costa Rica Costa Rica (, ; ; literally "Rich Coast"), officially the Republic of Costa Rica ( es, República de Costa Rica), is a country in the Central American region of North America, bordered by Nicaragua to the north, the Caribbean Sea to the no ...

and

Panama Panama ( , ; es, link=no, Panamá ), officially the Republic of Panama ( es, República de Panamá), is a transcontinental country spanning the southern part of North America and the northern part of South America. It is bordered by Cos ...

.HBW and BirdLife International (2020) ''Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world'' Version 5. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v5_Dec20.zip xls zipped 1 MBretrieved 27 May 2021

Taxonomy and systematics

The garden emerald was at one time considered a subspecies of the

blue-tailed emerald The blue-tailed emerald (''Chlorostilbon mellisugus'') is a hummingbird in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is found in tropical and subtropical South America east of the Andes from Colombia east to the Guianas and ...

(''Chlorostilbon mellisugus'').del Hoyo, J., N. Collar, G. M. Kirwan, and P. F. D. Boesman (2020). Garden Emerald (''Chlorostilbon assimilis''), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.gareme1.01 retrieved July 31, 2022 As its own species, it is

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

Description

The garden emerald is long and weighs about . The adult male has dark metallic green upperparts with bluish green uppertail

coverts A covert feather or tectrix on a bird is one of a set of feathers, called coverts (or ''tectrices''), which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail. Ear coverts The ear coverts are sm ...

. Its forked tail is blue-black and the central feathers have a light bluish green gloss. Its underparts are a brighter metallic green than the upperparts, sometimes with a light blue sheen, and it has white thigh tufts. The adult female has bright metallic green to bronze green upperparts with bluish green uppertail coverts. Its tail is blue-black, with dull metallic green central feathers and pale gray tips on the outer ones. It has dusky cheeks, a white or grayish white spot behind the eye, and pale gray underparts. Juvenile males are like the adult female but darker gray below.

Distribution and habitat

The garden emerald is found in southwestern Costa Rica, the Pacific coast of Panama, and the offshore Coiba and

Pearl A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle) of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carb ...

islands. It inhabits open landscapes like the edges of woodlands, hedgerows, streamside thickets, scrublands, and gardens. It is a bird of the lowlands, reaching from sea level to in Costa Rica and in Panama.

Behavior

Movement

The garden emerald is generally sedentary. However, there are reports of its moving back and forth between mainland Panama, the Pearl Islands, and other small islands.

Feeding

The garden emerald forages for nectar by

trap-lining In ethology and behavioral ecology, trap-lining or traplining is a feeding strategy in which an individual visits food sources on a regular, repeatable sequence, much as trappers check their lines of traps. Traplining is usually seen in species ...

, visiting a circuit of flowering trees, shrubs, and other plants. It also feeds on small insects that it gleans from vegetation.

Breeding

The garden emerald's breeding season has not been fully determined but in Panama appears to span at least from November to March. Its nest, incubation length, time to fledging, and other details of its breeding

phenology Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonality, seasonal and interannual variations in climate, as well as environmental factor, habitat factors (such as elevation). Examples includ ...

have not been documented. They are assumed to be similar to those of other ''

Chlorostilbon ''Chlorostilbon'' is a genus of hummingbird in the family Trochilidae, known as emeralds (as are some hummingbirds in the genera '' Amazilia'' and '' Elvira''). A single species, the blue-chinned sapphire is variously placed in the monotypic g ...

'' hummingbirds.

Vocalization

The garden emerald's vocalizations are not well known but appear to be similar to those of

Canivet's emerald Canivet's emerald (''Cynanthus canivetii'') is a species of hummingbird in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is found in Belize, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, and Nicaragua. Taxonomy and syste ...

(''Cynanthus canivetii''). That species' song is believed to be "an endlessly repeated, characterless wiry ''tseee tseeree''" and its call has been described as "a dry, scratchy chut or chit, sometimes run together into a soft, staccato chatter".Rodríguez-Flores, C. I. (2021). Canivet's Emerald (''Cynanthus canivetii''), version 1.1. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.caneme1.01.1 retrieved July 30, 2022

Status

The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has assessed the garden emerald as being of Least Concern. It has a large range and its estimated population of at least 50,000 mature individuals is believed to be stable. No immediate threats have been identified. It " adily accepts man-made habitat" and may even have expanded its range as forest has been cleared.