The Royal Sunangel (Heliangelus regalis) is endemic to sandstone ridges in southeast Ecuador and northeast Peru. This hummingbird is currently considered endangered, although little has been published on its natural history, distribution, and conservation. We found H. regalis in three habitat types, but abundance was higher in stunted shrubland, at ridgetops. It was observed to feed on seven plant species, mostly following regular feeding routes, between 0 and 2.5 m above ground. We describe six different vocalizations, as well as two flight displays, and observations on social interactions. We also discuss its current conservation status in Ecuador, where we estimate that ∼2,500 individuals might persist.