Jeff Podos (current professor at UMass Amherst) and João C.T. Menezes (former graduate student at UMass Amherst) have collected the max amplitude from 123 bird species. 113 of the 123 species have never had their volume catalogued. While conducting this research they may have found the two loudest birds in the world, the bare-throated bellbird, and the red-legged seriema.
Their goal wasn’t to find the loudest bird out there, but to test five hypotheses. Their hypotheses were that specific factors (large body size, larger beak gape, low flight mobility, dense habitats, and polygamous mating systems) would all cause higher amplitudes of vocalization. They recorded birds from December 2018 to January 2025, over 6 years of work, in Massachusetts and Brazil.
While conducting their study they found that there is a huge variation in max amplitude in birds. The maximum sound pressure (in decibels) was 122.4 dB, the lowest was 61.1 dB. In comparison a normal conversation is about 60 dB, and a concert or jet plane is around 120 dB.
While the data collected was able to support the hypothesis that larger body size, and larger beak gape results in higher maximum vocal amplitude, the data was unable to support their other hypotheses on mobility, habitats, and mating systems. This paper is a piece of the puzzle in determining why amplitude might serve as an ecological and evolutionary purpose.
To read Jeff Podos and João C.T. Menezes’s full paper, click here.