Concepts

Acoustic phenomena including subharmonics, biphonation, deterministic chaos, and warbles that occur when vocal production apparatus loses control

Morton's theory that physical behaviors and acoustic signals are associated, with aggressive behaviors linked to noisy, low-frequency sounds and submissive behaviors to higher-frequency pure tones

Hypothesis that nonlinear phenomena are more variable or more abrupt and therefore more unpredictable, making animals less likely to habituate to them and causing prolonged responses

Breeding birds must balance energy allocation between reproduction and survival, with parasites forcing energy towards immune response rather than reproductive traits

Physiological responses of the immune system to pathogens, trauma, stress and inflammation

A brief but generalized sickness syndrome triggered by bacterial infections and LPS injection