Dear colleagues, The following paper has recently been published: "Non-song acoustic communication in migrating humpback whales (Megaptera novaeangliae)" Marine Mammal Science, 24(3), 613 - 629 ABSTRACT: Humpback whales are renowned for the complex structured songs produced by males. A second, relatively understudied area of humpback acoustic communication concerns un-patterned sounds known as 'social sounds', produced by both males and females. These include vocalizations as well as sounds produced at the surface of the water as a result of surface behaviors (e.g. breaching, pectoral slapping). This study describes a portion of the non-song social sound repertoire of southward migrating humpbacks in Australian waters, and explores the social relevance of these sounds. On migration, humpback whales travel in social groups of varying compositions and social groups are not stable in that humpback whales continually change group composition by splitting from, or joining with, other groups. 'Breaching' and 'slapping' were suggested to have a communicative function. Other sounds such as 'underwater blows' and 'cries' were heard mainly in competitive groups whilst other low-frequency sounds such as 'grumbles', 'snorts', 'thwops' and 'wops' may function in intra or inter-group communication. Particular sounds ('grunts', 'groans' and 'barks') were almost exclusive to joining pods suggesting a role in social integration. Results suggest social sounds in humpbacks have specific social and behavioral functions relating to social group composition, and the mediation of interactions between these social groups. Pdf files of the paper are available from the Marine Mammal Science website or from r.dunlop@uq.edu.au Rebecca Dunlop Rebecca Dunlop BSc PhD Cetacean Ecology and Acoustics Laboratory School of Veterinary Science University of Queensland St Lucia, Qld 4072, Australia Ph. (07)3365-3066 Mob. 0437434041 Fax. (07)3365-1255 Email r.dunlop@uq.edu.au