The White-throated Hummingbird is recognized by its moss-green body and white throat and belly. The sources include records from Brazil, Uruguay, and Argentina.
Both sexes have moss-green bodies, bold white throats and bellies, and a red lower mandible.
It feeds on nectar around forest edges, marshes, scrub, parks, and gardens. eBird also notes that it visits feeders.
An extinction-risk assessment has not been added yet.