Anti-exhaustion hypothesis

The anti-exhaustion hypothesis is a possible explanation for the existence of large repertoires and the song switching behaviour exhibited in birds. This hypothesis states that muscle exhaustion occurring due to repeating song bouts can be avoided by switching to a different song in the bird's repertoire. The anti-exhaustion hypothesis therefore predicts that birds with larger repertoires are less susceptible to exhaustion because they can readily change the song that they are producing.

The anti-exhaustion hypothesis was first proposed by Marcel Lambrechts and André Dhondt in 1988 after they carried out a study using recordings from great tits, Parus major, during the dawn chorus. There have been several studies carried out in which results have contradicted the anti-exhaustion hypothesis. Recent studies have shown that there is no evidence that the anti-exhaustion hypothesis is the cause of large repertoires in birds. Since the proposal of the anti-exhaustion hypothesis, several hypotheses have been proposed to explain the existence of repertoires and song switching behaviour in birds, including the motivation hypothesis and the warm-up hypothesis.