Examining Individual Identity in Beluga Whale (Delphinapterus leucas) Acoustic Repertoires as a Function of Call Type

<p>Beluga whales (<em>Delphinapterus leucas</em>) are highly social odontocetes with complex vocal repertoires, yet it remains unclear if they encode individual identity within calls or how receivers interpret such cues. Their repertoire includes tonal and pulsed sounds, which exist along a graded spectrum and can be produced simultaneously through two pairs of phonic lips, creating multi-component signals referred to as biphonations. Complex contact calls, a type of biphonation, have the most observational evidence for individual specificity, but these findings have not yet been experimentally tested in a controlled setting. To test for individual identity across multiple call types, we conducted habituation-dishabituation playback experiments with five belugas at Georgia Aquarium, supplemented with calls from an outgroup at Oceanogràfic de Valencia. Responses were measured as the number and duration of looks and approaches toward the speaker and analyzed with generalized linear mixed models. Complex contact calls and biphonated pulsed tonals elicited significant habituation-dishabituation patterns, while biphonated r-shaped whistles trended toward significance. Simple contact calls and flat whistles did not show habituation but did show significant discrimination when caller identity changed. These results indicate that belugas do not just encode identity in a single call, but across multiple distinct vocalizations. By evaluating belugas’ behavioral responses, rather than inferring meaning from automated acoustic classification, our study links call structure to receiver-based processes that underlie individual vocal recognition. These findings provide the first experimental evidence that belugas discriminate between individual callers across their vocal repertoire, revealing a previously unrecognized level of auditory discrimination and cognitive sophistication.</p>

Name thesis:degree_name

Master of Science - Biology

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2025

Author dc:creator

• Schoenhoft, Sonny M

Contributors dc:contributor

• Dr. Jason Bruck

• belugas
• vocal recognition
• animal communication
• cetacean
• biphonation
• Behavior and Ethology
• Biology
• Integrative Biology
• Life Sciences
• Marine Biology

Repository record dc:identifier

https://scholarworks.sfasu.edu/etds/647

OAI identifier oai:identifier

oai:scholarworks.sfasu.edu:etds-1710