Deep in Brazil’s Serra do Mar mountains, a bird smaller than a dove produces metal-like calls louder than elephants and chain saws. According to a study in the journal Evolution, the bare-throated bellbird and the red-legged seriema rank among the loudest birds known to science, reaching between 121 and 122 decibels.
In the Atlantic forests of Brazil, the bare-throated bellbird pierces the dense canopy with a sharp, metallic ring designed to attract females. According to a new study published in the journal Evolution, this small bird and the red-legged seriema generate sound levels between 121 and 122 decibels, easily outpacing the volume of elephants, pneumatic hammers, and chainsaws.
Decibels in the Serra do Mar Mountains
Lead study author João Menezes noted that these deafening vocalizations can surpass the calls of much larger animals, including lions, wolves, and bison.
Meanwhile, co-researcher Jeff Bodus pointed out that the bellbird’s most striking feature is its ability to produce such immense sound despite its diminutive body size.
Savanna Adaptations of the Red-Legged Seriema
While the bellbird inhabits forested regions with a sharp metallic tone, the red-legged seriema roams the savanna. Approaching the height of a crane, the seriema performs complex and melacholic calls.
By comparison, some hummingbirds register only around 50 decibels, which is roughly equivalent to moderate rainfall.
Inside the Avian Syrinx and Brass-Instrument Physics
Birds produce sound through an organ known as the syrinx, where tissues vibrate as air passes from the lungs. The trachea then shapes the sound and boosts specific frequencies, functioning much like the tubing of brass instruments.
Bill Width and Air Pressure Mechanics
Comparative analyses also highlight the role of bill width and body size. Broader bills help radiate sound much like the flared end of a horn, while larger muscles generate the higher air pressure needed to sustain powerful calls.
