Humpback whales match song production to dive patterns

Abstract

Understanding the function and origin of a complex animal display requires a holistic study of its performance. For example, movement is linked to sound production 1,2,3,4,5,6 by enhancing or biomechanically facilitating displays, 7,8 exploiting additional sensory channels, 9,10 or affecting signal development and perception. 1,11,12 Among animal displays, humpback whale ( Megaptera novaeangliae ) song is remarkable for its hierarchical structure, syntax, and cultural transmission, 13,14,15,16,17,18,19 but it has been challenging to study the whole performance. Using temporarily attached sound and movement recording tags, we conducted an individual-level examination of fine-scale movement during humpback whale song performance. We discovered a tight correspondence between dives and songs, which were repeated without stopping for up to 16 h. Repeating song elements, known as themes, were linked to specific parts of a dive; ascent and descent song themes were consistent across individuals and years, while a greater number of theme types occurred at depth. Different levels of variability in song components across dive phases suggest that features of themes from the bottom portion of a dive, where the depth is stable, are more likely to be driven by song sharing under sexual selection. Movement during song performance illustrates important connections between physiology, environment, and behavior for learned, rhythmic acoustic displays.