Every spring, Mother Nature takes the choir out of the freezer. And sometimes – this year for example – she pops them back in for a while. The choir to which I refer is that all-male horde of early-spring frogs: spring peepers, wood frogs, and chorus frogs. Even while an ice rind still clings to the pond edges, untold numbers of these guys roust themselves from torpor to sing for female attention.
While in our species it is mostly an inflated ego which causes males to become unusually loud attention-mongers when seeking mates, it is an inflated vocal sac which allows male frogs to be so noisy. This air-filled structure balloons out tight, acting as a resonance chamber to amplify sound. I don’t know how it is with all frog species, but the inflated vocal sac of a peeper is almost as big as it is. This contrasts with the human male, whose ego can sometimes swell to many times his body size. » Continue Reading.