Parasites Garble Mating Calls

A parasite (Halipegus occidualis) that lodges in the mouths of American green tree frogs changes males’ honk characteristics — lowering pitch while shortening call duration. Female frogs respond by preferring moderately infected males over uninfected or heavily infected ones, indicating females integrate multiple signal cues to balance mate quality against infection risk. — Shows how hidden biological interference can corrupt signals and force receivers to make costly tradeoffs — a concrete example of when observable traits mislead and how information-processing strategies evolve.