The Scaly-breasted Hummingbird (Phaeochroa cuvierii) is a rather large and very plainly colored species about four and a half inches in length. The sexes are alike, and in both the upper plumage is metallic bronze-green.  There is a small, whitish spot behind each eye. 

Scaly-breasted Hummingbird at Birding Paradise 

The feathers of the throat and breast are dull green with grayish buff margins, producing the effect of scales when the hummingbird is viewed at close range. In the field, however, the scales are hardly noticeable.

Breeding occurs mainly during rainy season. The female is responsible for building the cup-shaped nest out of plant fibers woven together and green moss on the outside for camouflage in a protected location in a shrub, bush or tree.  The average clutch consists of two white eggs which she incubates alone, while the male defends his territory and the flowers he feeds on. The young are born blind, immobile and without any down. 

Their preferred habitats includes moist lowlands and foothils, including forest, mangroves, coffee plantations and open areas with scattered tall trees (particularly if blooming). It is divided into six subspecies which occur patchily in the lowlands and foothills of the Caribbean slope from southeast Mexico to Panama on the Pacific Slope of Costa Rica and Panama and the coastal region of Northern Colombia.  

Scaly-breasted Hummingbirds primarily feed on nectar taken from a variety of brightly colored, scented small flowers of trees, herbs, shrubs and epiphytes. They favor flowers with the highest sugar content (often red-colored and tubular-shaped) and seek out, and aggressively protect, those areas containing flowers with high energy nectar. They also take some small spiders and insects - important sources of protein particularly needed during the breeding season to ensure the proper development of their young.  

Not globally threatened. CITES II. Uncommon to locally common in most areas. Probably benefits from forest clearance in most areas. 

References:

Scaly-breasted Hummingbird (Phaeochroa cuvierii), In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. retrieved from Neotropical Birds Online:

https://neotropical.birds.cornell.edu/Species-Account/nb/species/scbhum1 

Skutch, Alexander F. "Life History of the Scaly-breasted Hummingbird."  The Condor, vol. 66, no. 3, 1964, pp. 186-198. JSTOR, JSTOR www.jstor.org/stable1365643.