In an effort to standardize how multi-looped whistles are treated across studies, we recently had a note accepted by the journal Marine Mammal Science demonstrating that inter-loop intervals in stereotyped sequences of disconnected loops (multiple elements) are shorter and more consistent (less variable) than are the intervals between successive whistles. For whistles with multiple disconnected loops, the stereotyped silence between loops may serve as another characteristic by which individual dolphins can distinguish themselves uniquely. In addition, the presence of a characteristic introductory or terminal loop in some signature whistles implies that the series of elements is produced as a punctuated unit. The results of this study indicate that it is appropriate to consider these loops as components of a single whistle, rather than as separate whistles. In addition, we extended the published value for maximum frequency of signature whistles to 27.3 kHz.

Argentinean trainee Agustina Caride helps keep a dolphin cool and wet during acoustic recordings and hearing tests.