Sperm whale codas may encode individuality as well as clan identity

Area of Science:

• Marine Biology
• Bioacoustics
• Animal Communication

Background:

• Sperm whales use codas for communication, leading to theories of distinct cultural clans.
• It remains unclear if codas also convey individual-specific information.
• Coda click pulse delays relate to organ and body size, a potential individual cue.

Purpose of the Study:

• To investigate if coda temporal patterns provide reliable individual identification cues in sperm whales.
• To determine if inter-click and inter-pulse intervals within codas are individually distinctive.
• To explore if sperm whales use different coda types during distinct behavioral contexts.

Main Methods:

• Stereo-hydrophone acoustic tags (Dtags) were deployed on five sperm whales in the Azores.
• A total of 802 codas were recorded and analyzed.
• Discriminant function analysis was applied to differentiate coda types and identify individual features.

Main Results:

• Consistent individual features were found in inter-click intervals and inter-pulse intervals of codas.
• Discriminant function analysis successfully distinguished coda types from different individuals.
• Two whales exhibited different coda types during distinct foraging dive phases, suggesting context-specific communication.

Conclusions:

• Sperm whale codas possess consistent individual characteristics, potentially aiding in individual recognition.
• Codas may convey both individual identity and activity status within social groups.
• This research expands the understanding of coda function beyond cultural transmission to include individual and contextual information.