As part of a Whale-SETI study, scientists from the SETI Institute, University of California Davis, and the Alaska Whale Foundation engaged in a 20-minute “conversation” with an adult female humpback whale named Twain off the coast of southeast Alaska in 2021. This acoustic exchange, facilitated through an underwater speaker playing back recorded humpback whale calls, provides intriguing evidence of whales’ capacity for interactive communication and hints at the potential to uncover nonhuman intelligence through further research.
The Study and Its Significance
The study, published in PeerJ, documents how Twain approached and circled the research vessel after hearing a “contact call” of her species played through the underwater speaker. Over the next 20 minutes, the researchers played the call in varying intervals, to which Twain responded by vocalizing after each playback, closely matching the timing of her calls to the recordings.
According to lead author Dr. Brenda McCowan, “this is likely the first communicative exchange between humans and humpback whales in the humpback ‘language’.” Her co-author Dr. Fred Sharpe emphasizes that humpback whales possess the hallmarks of intelligence: complex social relationships, cooperative hunting techniques, and an extensive vocal repertoire of songs and social calls.
The researchers’ ability to engage Twain through dynamic, responsive playback suggests that interactivity is key for eliciting meaningful communication from whales. It also lends credence to the assumption that extraterrestrials may similarly attempt to initiate contact. As Dr. Laurance Doyle explains, “an important assumption of the search for extraterrestrial intelligence is that extraterrestrials will be interested in making contact and so target human receivers. This important assumption is certainly supported by the behavior of humpback whales.”
Insight into Humpback Whale Communication
Humpback whales are known for their complex song sequences, used primarily during mating seasons. Their social calls serve additional purposes, like maintaining contact with their group. The “contact call” played back to Twain is common in their repertoire and helps whales reconnect or signal their location.
The study provides new insight into humpback communication by documenting Twain’s responses during three distinct phases:
Engagement (Phase 1): Twain moves closer to the boat, actively vocalizing after each playback at similar intervals as the recordings, indicating heightened arousal and interest.
Agitation (Phase 2): Twain produces agitated blowhole breaths as she follows the boat, responding less consistently to playbacks with longer call intervals, potentially showing frustration.
Disengagement (Phase 3): Twain increases distance from the boat and ceases vocalizing, despite further playbacks, marking the end of her interactivity.
This phased progression gives researchers a window into the changing motivational and emotional state underlying Twain’s behavior during the encounter. It also demonstrates her capacity to alter her vocal pacing and physical proximity in response to the dynamic stimuli.
Implications for Research into Nonhuman Intelligence
The researchers believe this case study highlights key considerations for designing experiments to uncover intelligence and flexibility in animal communication:
- Interactive, adaptive playbacks are more engaging than passive playbacks with fixed stimuli.
- Familiar calls recently recorded from known associates may be more salient stimuli than random calls.
- Deploying underwater microphone arrays helps corroborate acoustic data with behavioral observations.
- Independent, blind observer notes on visible surface behavior provide contextual clues to interpret acoustic responses.
Most strikingly, the exchange shows Twain’s aptitude for turn-taking, vocal matching of timing, and flexibility in responding to the unfamiliar situation. Her behavior mirrors prior findings on synchronous call timing in human conversations and in the communication patterns of dolphins, monkeys, and songbirds. This lends support for the cognitive complexity underlying interactive communication across some terrestrial and marine species.
The researchers therefore argue that adaptive vocal playbacks present a promising avenue for detecting intelligence in animals, including cetaceans like humpback whales. Further research could uncover the information-processing capacities that enable behaviors like turn-taking as well as the evolutionary pressures driving this conversational aptitude.
Broader Implications for the Search for Extraterrestrial Intelligence
This research forms part of the Whale-SETI project spearheaded by the SETI Institute, which studies whale communication to inform techniques for detecting intelligent alien life.
The logic is that while extraterrestrial intelligence may differ vastly from humanity, examples of intelligence in nonhuman terrestrial species can provide analogues and models to recognize unfamiliar signatures of intelligent communication.
In this vein, humpback whale behavior offers a window into how an alien species may seek to establish contact by capitalizing on conventions shared by intelligent creatures. These include curiosity, flexibility in novel situations, and the use of interactive signaling.
By developing methods based on information theory and animal cognition to decode complex communication in whales, the researchers hope to pave the way for identifying and translating messages from extraterrestrials if contact is ever made.
The encounter with Twain is thus a proof of concept suggesting that interaction and exchange are pivotal for tapping into intelligence, whether in our oceans or across the cosmos. As we expand concepts of intelligence beyond anthropocentric views, such interspecies communication could uncover hidden depths of mental complexity in life on Earth and beyond.