Juvenile males are similar to the adult female but with darker underparts and buff fringes on the chest feathers.

[6] The garnet-throated hummingbird is found discontinuously from Mexico's Guerrero, Puebla, and Veracruz states south through Guatemala into El Salvador and Honduras.

[6] The garnet-throated hummingbird feeds on nectar from flowering shrubs and trees, especially those of genera Inga and Erythrina.

In addition to nectar, the species feeds on small insects captured by hawking from a perch.

The female builds a bulky cup nest of moss, leaf parts, and pine needles lined with softer plant fibers.

The garnet-throated hummingbird's song is "a soft, gruff, dry, crackling warble intermixed by nasal, gurgling notes."

"[6] The IUCN has assessed the garnet-throated hummingbird as being of least concern, though its population size and trend are not known.