Radiolab – "Wild Talk" (October 18, 2010)
Episode Overview
In this episode of Radiolab, hosts Jad Abumrad and Robert Krulwich embark on a journey into the world of animal communication, asking: How much language is hiding in wild animal chatter? The show investigates the “words” in nature, highlighting scientific discoveries about how creatures from monkeys in African jungles to prairie dogs on the American plains signal, warn, and perhaps even describe the world—and each other. This exploration not only questions the boundaries of human language but also the nature of communication in the wild.
Key Discussion Points & Insights
I. Introduction – Wild Places, Wild Voices
[01:49 - 02:32]
- Jad and Robert frame the episode as an exploration of how listening closely in the wild reveals a “language” in the chaos of animal sounds.
- Robert: “There is now a group of scientists… reducing wildlife to wild talk. There are words in there.” [01:58]
II. Jungle Study: Diana Monkeys in the Ivory Coast
[02:45 - 07:19]
- Researchers: Klaus Zuberbuller (professor of psychology, University of St. Andrews, Scotland) is introduced by Ari Daniel Shapiro.
- Setting: The dense, “cathedral-like” Tai Forest in Ivory Coast, Africa, described as sensory-rich, noisy, and visually impenetrable.
- Klaus: “Sometimes you feel like you walk through a big cathedral of dark trees...” [03:34]
- Focus: Diana monkeys, their alarming cacophony, and the quest to decode their sounds.
- Method: Klaus plays recordings of predator sounds to provoke alarm calls:
- Leopard sound elicits one kind of alarm call.
- Crowned eagle sound elicits a call that sounds similar to the untrained ear.
- Discovery: Subtle but consistent acoustic differences in monkey calls depending on the predator (revealed via spectrograms and, later, trained listening).
- Klaus: “When you know what to pay attention to, you go out into the forest and suddenly you do hear these differences...” [06:58]
- Insight: Monkeys use distinct vocalizations as “words” for specific threats, prompting different escape strategies (climb up for leopards, down for eagles).
III. Prairie Dogs: The Rodent Linguists
[07:24 - 14:21]
- Expert: Kahn Slobochikoff, professor emeritus at Northern Arizona University, studies prairie dog communication.
- Observation: Prairie dogs have different “chee” calls for humans, coyotes, and dogs—but distinctions are inaudible to humans.
- Method: Computer analysis (spectrograms) teases out nuanced sound differences.
- Jad demonstrates with sound layering: “This sound is filled with little ghost notes we can’t hear...” [10:34]
- Breakthrough: Within the “here comes the human” calls, further subtle variation hints at descriptive information (color of shirt, height).
- Kahn: “What if they could be describing the individual humans?” [11:25]
- Experiment: Four humans dressed identically except for shirt color walk past the colony; prairie dog calls cluster by shirt color and even human height.
- Kahn: “Essentially, they were saying, here comes the tall human in the blue versus here comes the short human in the yellow.” [12:41]
- Shape Discrimination: Prairie dogs can distinguish flying triangles (hawk-shaped) from circles and squares, possibly mapping shapes to potential threats.
- Kahn: “Triangles kind of look like hawks. Circles and squares look like terrestrial predators.” [13:57]
- Vocabulary Extent: Their calls encode information such as species, color, size, and even shape.
- Jad: “What you’ve got here is a little rodent with a remarkably big vocabulary...” [14:08]
IV. “Bilingualism” in the Jungle: Eavesdropping Among Species
[15:09 - 17:32]
- Big Question: Can animals “overhear” or encode meaning from the calls of other species, like humans picking up on a foreign conversation?
- Robert: “Is there an equivalent of listening to the other person talking French in the wild?” [15:43]
- Klaus’s Experiment: Diana monkeys and Campbell’s monkeys live alongside many other primate species in the Tai forest.
- Alarm calls of one species (e.g., Campbell’s monkeys) are played for another (Diana monkeys). Result: Diana monkeys respond correctly to the alarm, indicating cross-species understanding.
- Klaus: “To our great surprise…they understand it... they take that very, very seriously and respond to it very strongly.” [16:52]
- Beyond Monkeys: Even birds (yellow-casked hornbills) key into these primate alarm calls; an intricate communication web exists.
- Klaus: “It’s a pretty substantial web of species basically eavesdropping on each other’s calls.” [17:23]
V. Becoming Part of the Wild Conversation
[17:34 - 21:11]
- Klaus recounts a personal, transformative moment in the forest:
- Walking alone, he hears Diana monkeys issuing sequential leopard calls, tracking his path.
- He realizes the monkeys are warning of a stalking leopard.
- Klaus: “I was suddenly able to understand what the monkey’s trying to say, so to speak.” [18:25]
- The experience shifts him from observer to participant, “the 11th primate,” in the web of communication.
- Klaus: “Suddenly, I shifted from being the objective observer to being, you know, sort of part of that whole crowd in there.” [20:17]
- Emotional resonance: Despite 20–30 million years of evolutionary divergence, he feels “taught” by the humble creatures—highlighting both the divide and the fleeting connections possible between species.
Notable Quotes & Memorable Moments
- Robert Krulwich: “It’s really kind of like a word. It’s like a word—that’s kind of amazing.” [07:19]
- Kahn Slobochikoff (on individuality in prairie dog calls): “Oh, I was astounded. I was astounded.” [12:20]
- Klaus Zuberbuller: “So it’s a pretty substantial web of species basically eavesdropping on each other’s calls in these forests.” [17:23]
- Klaus Zuberbuller (on becoming the 11th primate): “Suddenly, I shifted from being the objective observer to being, you know, sort of part of that whole crowd in there.” [20:17]
- Kahn Slobochikoff (on prairie dog “chatter”): “Could be just simply chatter, chitter, chitter. Or it could be, do you know where Sam was last night?” [14:31]
Important Segment Timestamps
- [02:45] — Introduction of Ari Daniel Shapiro and Klaus Zuberbuller; setting the jungle scene
- [05:10] — Playing predator sounds and observing Diana monkey responses
- [06:44] — Discovery of nuanced alarm calls as unique “words”
- [07:51] — Transition to prairie dog story with Kahn Slobochikoff
- [11:25] — Realization that prairie dogs may describe individual humans
- [13:00] — Experiment with flying shapes over prairie dog colony
- [15:43] — Discussion of “wild eavesdropping” and cross-species communication
- [16:46] — Diana monkeys’ understanding of Campbell’s monkeys’ alarm calls
- [17:34] — Klaus’s dramatic encounter with a (stalking) leopard, signaled by monkey alarm calls
- [20:17] — Emotional reflection on becoming part of the forest’s communication network
Episode Takeaways
- Animal “language” is more complex and nuanced than previously assumed, encoding not just warnings but potentially descriptions and identities.
- Different species, and even different classes of animals (such as birds and primates), can eavesdrop and interpret each other’s alarm calls, building a shared web of meaning in the wild.
- Interpreting and being part of this wild conversation can be a profound and humbling experience, reminding listeners of the evolutionary ties and differences that connect and separate all living things.
- Radiolab’s tone balances scientific rigor with wonder, curiosity, and humor—inviting listeners to join in the adventure of decoding the wild.