A giant’s dance: underwater social and vocal behavior of humpback whales (Megaptera novaeangliae) recorded on the Northern Coast of Ecuador

On their tropical breeding grounds humpback whales (Megaptera novaeangliae) produce an array of social behaviors. The most commonly reported behaviors are surface active displays, which include tail, pectoral, or full body slapping events (Kavanagh et al., 2017). Social interactions also comprise a diverse range of sub-surface behaviors that include calls (Dunlop et al., 2007; Zoidis et al. 2008; Seger, 2016). The function of most social behaviors within humpback whale groups remains unclear; whales spend most of their time underwater and their behavioral repertoire is thus obscured due to inherent difficulties in documentation in this environment. For example, synchronized movements and tactile signals occur underwater during social group interactions (e.g. between mothers and calves or within competitive groups) and these behaviors may play an important role in their social lives and communication (Darling & Berube, 2001; Zoidis et al., 2008, 2014). As such, multiple functions have been proposed and the significance of social behaviors, including underwater displays, are still debated for humpback whales and most marine mammal species (Dudzinski et al., 2009).