Esmeralda de Panamá/Garden Emerald/Chlorostilbon assimilis

Nombre en español: Esmeralda de Panamá

Nombre en inglés: Garden Emerald

Nombre científico: Chlorostilbon assimilis

Canto: Brendan Sloan

El esmeralda de Panamá, esmeralda de Jardín, esmeralda jardinera, esmeralda jardinero o esmeralda afín (Chlorostilbon assimilis) es una especie de ave en la familia Trochilidae. Antiguamente se lo consideraba una subespecie de Chlorostilbon mellisugus.

Descripción

Mide 8 cm de largo y pesa 2.6 g. Las partes superiores del macho son bronceadas, sus partes inferiores son verde brillante, con grupas blancas y una cola muy ahorquillada. Las partes inferiores de la hembra son grises, posee una franja blanca detrás del ojo y manchas en los oídos. Su cola posee puntas blancas, el diseño ahorquillado profundo de la cola del macho. Los ejemplares juveniles se asemejan a la hembra adulta, pero poseen extremos rufos claros en sus plumas.

Distribución y hábitat

Este pequeño colibrí es un reproductor endémico de Costa Rica y el oeste de Panamá. Esta especie habita en espacio abiertos, incluidos sabana arbustiva, prados, plantíos y jardines. Se lo encuentra en zonas bajas y colinas del Pacífico, en elevaciones de hasta 1500 m.

Ecología

El nido es una copa prolija de fibras vegetales decorada en su cara exterior con trozos de corteza. La hembra incuba dos huevos blancos.

Su llamada es un chit breve, y el canto del macho es un débil tsippy tsee tsee. Los machos en época de reproducción se posan en ramas y pueden lucir su vuelo.

Estas aves visitan flores pequeñas, incluidas aquellas ignoradas por otras especies, y capturan insectos diminutos. A menudo son espantados por colibríes más grandes.

Garden emerald

The garden emerald (Chlorostilbon assimilis) is a small hummingbird in the «emeralds», tribe Trochilini of subfamily Trochilinae. It is found in Costa Rica and Panama.

Taxonomy and systematics

The garden emerald was at one time considered a subspecies of the blue-tailed emerald (Chlorostilbon mellisugus). As its own species, it is monotypic.

Description

The garden emerald is 7.8 to 8.5 cm (3.1 to 3.3 in) long and weighs about 3 to 4.1 g (0.11 to 0.14 oz). The adult male has dark metallic green upperparts with bluish green uppertail coverts. 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 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 1,500 m (4,900 ft) in Costa Rica and 1,200 m (3,900 ft) 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, 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 have not been documented. They are assumed to be similar to those of other Chlorostilbon hummingbirds.

Vocalization

The garden emerald’s vocalizations are not well known but appear to be similar to those of Canivet’s emerald (Cynanthus canivetii).^[5] 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».

Status

The IUCN 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 «[r]eadily accepts man-made habitat» and may even have expanded its range as forest has been cleared.