[4][3][5] The copper-rumped hummingbird was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae.

[6] Gmelin based his description on the "Tobago Humming-Bird" that had been described in 1782 by the English ornithologist John Latham in his A General Synopsis of Birds.

[8] In the revised classification to create monophyletic genera, the copper-rumped hummingbird was moved by most taxonomic systems to the resurrected genus Saucerottia.

The epithet was coined in 1846 by Adolphe Delattre and Jules Bourcier to honor the French physician and ornithologist Antoine Constant Saucerotte.

Both sexes of all subspecies have a straight, medium length, blackish bill with a pinkish base to the mandible.

Adult females are similar though their upperparts are a less intense bronze-green and they have some whitish on the chin and upper throat.

[15] The island subspecies of copper-rumped hummingbird are sedentary; the mainland ones make some local movements.

[15] The copper-rumped hummingbird's breeding season on Trinidad is almost year-round, excluding only September and October; its peak is from January to March.

The copper-rumped hummingbird's song is "a repeated phrase of three buzzy or squeaky, well-spaced notes 'tee-dee-dew' or 'tee-dzee-djit'."

[15] The IUCN has assessed the copper-rumped hummingbird as being of Least Concern, though its population size and trend are unknown.