Why the Loudest Birds Don’t Sing the Fanciest Songs

A study of bird vocalizations has put two species forward as new contenders for the title of world’s loudest bird. It also points, in its title, to a relationship between very loud calls and less sophisticated songs.

The study, “The songs of screaming birds are less sophisticated than whisperers,” appeared in the Journal of Experimental Biology on July 15, 2025. According to NPR’s reporting, João Menezes, then a PhD student at the University of Massachusetts Amherst, and an adviser recorded loudness for 123 bird species in western Massachusetts and Brazil.

NPR reports that the measured range spanned roughly 800-fold, from a hummingbird at the quiet end to a trio of birds at the loud end. The report names the bare-throated bellbird and red-legged seriema as new contenders for the world’s loudest-bird title. That is not the same as a confirmed record: NPR frames both as contenders rather than definitive winners.

The reporting also identifies a pattern in the recordings: larger species and birds with wider mouth openings tended to be louder. But it says the drivers of the full variation in loudness are still unclear. The available source material does not establish a mechanism for that pattern, so it would be premature to infer one.

The paper’s title signals its other central question, pairing “screaming birds” with “whisperers” and suggesting a relationship between loudness and song sophistication. The verified material available for this article does not provide further detail on how song complexity was measured or what might account for the relationship.

The work therefore offers a useful reminder of the extraordinary range of bird sound while leaving important questions open. The full study is available through its DOI.