This is a video of a white-chested emerald hummingbird.
From 10,000 Birds blog; with photos there:
By Mike • August 25, 2012
The Republic of Trinidad and Tobago may share equal billing in the dichotomous nation’s name, but Trinidad boasts the lion’s share of the land mass, population, and hummingbirds. My focus during my June 2012 visit was obviously on the hummingbirds.
Visitors to Trinidad can scarcely help encountering stunning hummers just about everywhere. Between them, Trinidad and Tobago boast 17 species, of which several of which are extremely rare or accidental and one — the endangered White-tailed Sabrewing — can only be found in Tobago and. Most of the usual Trinidadian hummers frequent the feeders at the Asa Wright Nature Centre. The legendary veranda is the perfect place to spy Blue-chinned Sapphire, White-chested Emerald, and three different hermits (Rufous-breasted, Green, and Little) while enjoying good, strong coffee or even stronger beverages.
Are you curious to know the size of the hummingbird chicks? Check out this photo.