Meeting Abstract
Although the production of underwater bubbles has been documented in a number of cetacean species, an understanding of this category of behavior in terms of ecological, cognitive, and social contexts is only beginning to emerge. The present study focused on underwater bubbling behavior in a captive population of beluga whales (Delphinapterus leucas), with the goal of characterizing the extent of bubble production as a function of age, sex, and bubble type. Bubbles were recorded as stemming from both the blowhole and the mouth, and were categorized as conforming to four main shapes (Burst, Stream, Drips, and Rings). Nearly all bubbles fell into four source-shape combinations, or types (Blowhole Bursts, Blowhole Drips, Blowhole Streams, and Mouth Rings). A GLMM analysis revealed a significant three-way interaction of sex, age, and bubble type on rates of production. For Blowhole Bursts, the rate per minute in adults was higher for females than males, but in juveniles was higher for males than females. Blowhole Streams were produced at higher rates by males across both age categories. Both Blowhole Drips and Mouth Rings were produced more frequently by females than by males and by juveniles than by adults. The results of this study confirm that underwater bubbling is a common and widespread behavior in all sexes and age classes of the population studied, but suggest that roles played by bubbling do vary with age, sex, and bubble type.
