The Brace’s emerald (Chlorostilbon bracei) is a species of hummingbird that is found in western Panama and Costa Rica. It is a small hummingbird, measuring around 9-10 cm in length and weighing 4-5 grams. The male has glossy green upperparts and white underparts, with a straight black bill. The female is similar but has greyer underparts. The species was named after William Brace, an American ornithologist.
Range and Habitats
Brace’s emerald is found along the Pacific slope of Costa Rica and western Panama. Its range extends from the Cordillera de Talamanca in Costa Rica to western Panama. It occurs at elevations from around 500 to 1500 m.
This hummingbird inhabits a range of forest habitats, including humid foothill forest, cloud forest, and edges. It is often found around forest clearings and secondary growth. It prefers areas with plenty of flowering plants and a dense understory. Some key plants it visits include Inga, Psittacanthus, Centropogon, besleria, and various Heliconia species.
Identification
Brace’s emerald can be identified by its small size, green upperparts, white underparts, and straight black bill. The glossy green upperparts help distinguish it from the very similar Coppery-headed emerald, which has more bronzy-toned plumage. The white underparts help separate it from other small hummingbirds in the region like the Scintillant hummingbird.
The male Brace’s emerald has bright green upperparts that appear black in poor light conditions. It has brilliant green uppertail coverts. The underparts are white from the throat to undertail coverts. The tail is mainly black, with white outer corners. The bill is straight and black.
Females are similar, but less vibrant, with more greyish underparts. Immature birds resemble adult females.
Behaviour
Like most hummingbirds, Brace’s emerald feeds mainly on nectar taken from a variety of brightly colored, scented small flowers of herbs, shrubs and small trees. It favors flowers located in forest clearings. This species obtains most of the insects and spiders it requires for protein from spiders webs.
Brace’s emerald is pugnacious, chasing away larger birds as well as conspecifics from flowers and feeding areas. Males are highly territorial and engage in aerial displays to defend their territories and court females.
Breeding takes place between March and June. The female builds a small cup nest out of plant down and fibers on a low horizontal branch, usually over a stream or gully. She lays two white eggs, which she incubates alone for 15-19 days. The chicks fledge after about 20-26 days.
Status and Conservation
Brace’s emerald has a restricted range but is described as fairly common in suitable habitat. Its population is suspected to be decreasing moderately rapidly due to habitat destruction. BirdLife International categorizes this species as Near Threatened.
The major threats faced by Brace’s emerald are habitat loss due to logging and conversion of forests to plantations. Climate change may also pose a long-term threat, by altering the cloud forest ecosystem.
Conservation actions recommended for this species include protecting key sites and habitat corridors in its range. Monitoring of population trends is also needed. Raising awareness of its protected status among local communities is another important conservation measure.
Interesting Facts
– Brace’s emerald is one of the smallest hummingbirds in the world, averaging just 9-10 cm long.
– Like other hummingbirds, it can beat its wings up to 70 times per second. This allows it to precisely maintain position while feeding.
– To conserve energy, Brace’s emerald enters torpor, a state of decreased physiological activity, at night. Its body temperature drops and metabolism slows dramatically.
– This hummingbird has an intricate courtship display. Males fly in u-shaped patterns to attract females. They also vocalize with squeaky song notes.
– Brace’s emerald is important in pollinating many flowering plants in its cloud forest habitat. Without it, regeneration would suffer.
– The species is named after William Brace, an American ornithologist who collected the first specimens in Costa Rica. He described the species in 1948.
In summary, Brace’s emerald is a tiny and dazzling green hummingbird that is an important pollinator in Central American cloud forests. Its restricted range and threats from deforestation mean it faces an uncertain future. Protecting habitat corridors and engaging local communities will be key to ensuring the long-term survival of this species.