Complex Communication System among Sperm Whales

Why in News?

Scientists using artificial intelligence (AI) have uncovered a complex communication system among sperm whales, identifying a kind of phonetic alphabet.

• Sperm whales are highly social, deep-diving marine mammals that live in close family units.
• Sperm whales living in the eastern Mediterranean Sea have developed a distinct regional dialect that separates them from populations living in the west.
• Analysis led by - Project CETI (Cetacean Translation Initiative).

Project CETI is to cross-reference the newly discovered phonetic building blocks with observed physical behaviours.

• Acoustic labels –
  • Codas - While hunting for prey like giant squid thousands of feet below the surface, they maintain constant contact by emitting rapid bursts of clicks called codas.
  • Historically, scientists viewed these sounds as basic acoustic labels.
  • The computer models identified that the animals alter their vocalizations through specific structural adjustments.
  • Rubato - Whales deliberately manipulate the tempo and rhythm, a feature researchers called rubato.
  • They also frequently append an extra click to the end of a sequence, termed ornamentation.
• While Caribbean whales are demonstrating how complex these basic linguistic blocks can be, sperm whales in the Mediterranean Sea shows how these sounds change over geographical distances.
• Scientists believed all of these whales used an identical vocal signature known as the 3+1 coda, consisting of 3 rapid clicks, a brief pause, and a final 4^th click.
• Whales living in the western Mediterranean, near Spain's Balearic Islands, strictly maintain the traditional 3+1 pattern.
• However, the population residing in the eastern Mediterranean, near the Hellenic Trench off Crete, utilizes a sped-up version of the exact same sequence.
• The precise meaning of the 156 Caribbean codas and the underlying purpose of the Mediterranean dialect shift remain unknown.
• Modern threats – Hunting, ship strikes, entanglement in heavy commercial fishing gear, rising ocean noise levels, and changing marine ecosystems driven by climate change.
• Conservation - Unlocking their communication system could alter how human conservation programs protect these vulnerable populations.

Reference

Times of India | Sperm Whales vocalization