Bird vocalizations are critical cues in social interactions as they convey temporary information varying with the social context, e.g. the signaler motivation when facing a rival or a potential mate. To date, literature mainly focuses on learning birds. Burrowing petrels (Procellariidae) are non-learning birds with a limited vocal repertoire. Bachelor males communicate with conspecifics with a single call emitted in three situations: in absence of a certain auditory (spontaneous calls), towards females (female-directed calls) and...