White-tailed Emerald

How to find it

Go in the morning, which is generally the best time for hummingbirds, and search flowering plants, forest edges, shaded plantations and cloud forest gardens. In dense vegetation the bird is hard to spot by sight, so listen for brief high-pitched calls. Watch for the white tail flashing in flight. Look higher up at forest edges, where this emerald is favoured. Since some birds move up and down the slope outside the breeding season, it may be worth trying more than one elevation.

How to recognise it

This is a tiny, compact green hummingbird with a short, nearly straight bill. The bill is black with a pinkish base on the lower half.

The most useful field mark is the white outer tail feathers with dark tips. The white tail shows as a flash in flight.

Males have green underparts, a blue to violet crown, a white spot behind the eye and a white stripe down the belly.

Females are paler below, with a mostly white throat and underparts. Their white outer tail feathers have a dark band near the tip.

Behaviour and diet

It takes nectar from shrubs and vines, at the forest edge or inside the forest, and it also catches small flying arthropods in the air. Females tend to stay low in the understory, while males spend more time up in the forest canopy.

Males display to females at leks in small groups. The female alone builds a small cup nest of plant fibres and moss bound with spiderweb, often with lichen on the outside. She lays two white eggs and raises the young alone.

Where it lives

It lives on the Pacific slope of the Talamanca range, from southwest Costa Rica to central Panama. It is generally found from about 750 to 2,000 m above sea level, and in Costa Rica it breeds mostly between about 1,000 and 1,700 m. Some birds move up and down the mountains outside the breeding season.

It uses humid to wet mountain forest, forest edges, older second growth, shaded coffee plantations and gardens. It can use altered habitats if flowering plants remain.

When to see it

The breeding season runs from June to November, when males display at leks in small groups. In Costa Rica some birds move up and down the mountains outside the breeding season.

Similar birds

Next to the very common Rufous-tailed Hummingbird, this emerald has a white outer tail instead of a rufous one. The white shows even in flight, and the emerald favours higher forest edges. The male has a green wing patch, while the slightly larger Stripe-tailed Hummingbird has a bronze one.

Names and lore in Costa Rica

Costa Rican names for the species include Esmeralda Coliblanca, the AOCR name. Other Spanish names in use are Esmeralda de Cola Blanca and Esmeralda de Elvira, the last from its old genus name Elvira.

Status and conservation

The AOCR list gives it as a resident regional endemic (R-END), and the IUCN lists it as Least Concern, fairly common and found only in Costa Rica and Panama.

Photography tips

Go in the morning and settle beside flowering plants or a flowering garden at a forest edge, where hummingbirds feed. The white outer tail is the mark to watch for, as it flashes in flight. In dense vegetation, brief high-pitched calls can tell you where the bird is when foliage blocks the view.