In a study published Tuesday in the journal Royal Society Open Science, researchers found evidence of biofluorescence in most birds-of-paradise species.

New research reports, for the first time, the widespread occurrence of biofluorescence in birds-of-paradise. The study, based on specimens collected since the 1800s, finds biofluorescence in 37 of the 45 known birds-of-paradise species and suggests that this special “glow” is important among males for hierarchy and mating displays.