However, as of 2020, BirdLife International's Handbook of the Birds of the World (HBW) retains the single species "magnificent" hummingbird treatment.

[3] Rivoli's hummingbird is about 11 to 14 cm (4.3 to 5.5 in) long and weighs about 6 to 10 g (0.21 to 0.35 oz), with males typically a little larger than females.

The crown is violet, the throat gorget bright blue-green, and the rest of the head black apart from a white spot behind the eye.

Rivoli's coexists with many other hummingbird species including black-chinned (Archilocus alexandri) and broad-tailed (Selasphorus platycercus).

In Mexico they tend to dominate smaller hummingbirds such as amethyst-throated (Lampornis amethystinus), berylline (Saucerottia beryllina), and bumblebee (Atthis heloisa).

[7] Rivoli's hummingbird feeds on nectar from a wide variety of flowering plants whose composition varies by season, elevation, and latitude.

[7] The Rivoli's hummingbird breeding season spans from May to July in the U.S and is possibly year-round in El Salvador.

It builds an open cup nest of soft feathers and moss bound with spider silk and covered with lichen.

[7] The IUCN follows HBW taxonomy and so treats Rivoli's and Talamanca hummingbirds as a single species assessed as being of Least Concern.

[1] Forest fires are a potential threat in the U.S. because Rivoli's is found only in higher isolated mountain ranges.