Digest: Morphology shapes vocal amplitude in birds, while the role of ecology remains unclear

Why are some birds louder than others? Menezes and Podos (2026) examined vocal amplitude across 123 bird species, revealing substantial variation in how loudly different bird species communicate. Vocal amplitude was primarily associated with body size and beak gape width, whereas ecological factors showed no significant relationships. Despite the potential role of loud calls in attracting mates, the analyses found no clear relationship between vocal amplitude and polygamy.