Call Notes

Call notes are typically innate (genetically encoded) rather than learned, unlike song. Flight calls given by nocturnal migrants are species-specific and form the basis of acoustic migration monitoring — arrays of microphones connected to AI classifiers can now census migrating species by their flight calls in real time. Alarm calls often share acoustic properties across species (high-pitched, frequency-modulated tones difficult to localize), enabling heterospecific eavesdropping and interspecific alarm call networks.