White-bellied Mountain-gem

How to find it

Start at the hummingbird feeders at the Cinchona roadside cafe, where this mountain-gem is listed among the visitors. One birding guide found it showing well there, which makes it a reliable place to look. The feeders also draw tanagers, barbets, toucanets and many other hummingbirds. Away from feeders, look for clumps of flowering epiphytes in the canopy and at forest edges on the Caribbean slope. Males defend these flowers, so watch for chases. Along the Tapantí park road, scan blossoms at the road edge, because females turn up feeding at flowering trees there. One photographer reports seeing only females at Soda Cinchona and La Paz Waterfall Gardens, so a male may take more patience.

How to recognise it

Start with the white stripe behind the eye. It is a key mark in both sexes, and in Costa Rica that stripe together with the white underparts is enough to identify the bird. The tail also looks bronzy.

The male has:

- a glittering green crown and face

- a blue-violet throat

- a bright white belly with green speckles on the sides

Females lack the glittering green head and the violet throat. Their throat is white with green speckles. They also have gray tips on the outer tail feathers, a black bill and dusky flesh-colored legs. Young birds show rusty edges on the green feathers.

It is a small hummingbird, about 10 to 11 cm long. Males weigh about 6.2 g and females about 5.1 g.

Behaviour and diet

This is a hummingbird that takes what it wants. Males are aggressive at flowers and often drive off larger hummingbirds at clumps of flowering epiphytes. In the breeding season they defend feeding sites with persistent song and fast chases through the canopy.

It feeds on nectar from flowering trees and shrubs, and it also catches insects in flight.

Where it lives

It lives in the canopy and edges of very wet forest. It comes down to shrub level in open understory, gaps and clearings, and it mostly avoids secondary forest and semi-open country.

In Costa Rica it is a locally common resident on the Caribbean slope, from the Tilaltán range and Arenal Volcano south to Panama, at middle to low elevations of about 700 to 1,400 m. It breeds at roughly 700 to 1,400 m. After breeding it moves downslope to about 400 to 600 m.

When to see it

It breeds from about August or September to March in Costa Rica. Its nest has not been described.

Similar birds

At La Paz Waterfall Gardens a birder first mistook a mountain-gem for a female Green-crowned Brilliant, which was abundant at the feeders. Check the underparts: a female mountain-gem is bright white underneath, which a female Talamanca (Magnificent) Hummingbird is not. The vent is white on the mountain-gem and dark on both the brilliant and the Talamanca.

Names and lore in Costa Rica

Besides the AOCR name, Spanish sources call it Colibrí Gorgivioleta, for the violet throat, and Gema de Vientre Blanco.

Status and conservation

The AOCR list marks it R-END, a resident regional endemic, and the IUCN rates it Least Concern.

Photography tips

Feeders give the easiest views, and no hiking is needed. Away from them, watch clumps of flowering epiphytes, where males chase rivals and often perch in the open. Along the Tapantí park road, scan the blossoms at the road edge for feeding females.