The vocal repertoire of the Azure Jay Cyanocorax caeruleus (Vieillot, 1818) is approached from a quali-quantitative point of view. The qualitative analysis was carried out both in the field and in captivity: the quantitative analysis was made only in captivity. Social acoustic communication in the Azure Jay is achieved through the use of two types of call: basic and intermediate calls. Fourteen basic calls are identified and presented through sonograms: the sotto voce song (courtship call) is related only to courtship and the social call is interpreted as the song in the Azure Jay. The intermediate calls are recombinations of the basic calls uttered during an alteration in motivation level. Examples of them are presented through sonograms of vocalizations recorded during mobbing predators and intraspecific agonistic contexts. The social, social-alarm, contact, flight, proximity, threat and social identity calls were those most frequently uttered by daylight: the other calls represented around 15% of the total number of utterances. The hypothesis of the evolution in American Jays, which tends to simplification of vocal repertoire (HARDY, 1961; 1969), is analysed; C. caeruleus seems to have a small actively-used repertoire.
Aves; Corvidae; Cyanocorax caeruleus; repertoire; behavior