the warm-up hypothesis proposed by schraft et al. (2016) seems to contradict the anti-exhaustion hypothesis . this hypothesis foresees that birds have greater singing performance depending on the number of songs the bird has sang that day, known as recent practice, regardless of song type. this study was carried out between march and june 2012 at the cabo rojo national wildlife refuge in puerto rico. male adelaide's warblers, "setophaga adelaidae," recorded during their breeding season in their resident woods were found to have an average repertoire of 29 songs/male.