Prairie dogs have a lot more in common with the beer-guzzling, face-painted denizens of football stadiums than you might think. Both use a very important tool to interact with their neighbors: the wave.
University of Manitoba biologist James Hare and colleagues were investigating the black-tailed prairie dog and a particular behavioral tic called “jump-yip displays,” where the little critters hop up on their hind legs, wave their front paws, and make a noise that sounds like “wee-oo”:
Other scientists have thought that the prairie dog wave behavior is a kind of all-clear signal, but Hare and colleagues weren’t so sure. They observed that zoo prairie dogs would engage in jump-yip displays even when predators weren’t nearby. To investigate further, the team recorded 173 jump-yip sequences from 16 distinct prairie dog "towns" in South Dakota, North Dakota, and Winnipeg, Canada. The reported on their research in a paper published Tuesday in Proceedings of the Royal Society B.
What they observed suggests that this wave behavior is something like a test of the emergency broadcast system for prairie dogs. Individuals are basically using it to test their neighbor’s situational awareness and make sure everyone’s on guard. A prairie dog that initiates a ripple of jump-yips would relax more and look for food – and thus, spend not as much time watching out for predators – if the signal spread quickly. If the instigator’s neighbors were slow to respond, the instigating prairie dog wouldn’t forage as much, keeping more of a vigilant eye out for threats.
"Probably the most striking implication of the whole thing is it reveals to us that these prairie dogs have a concept of others as unique individuals," Hare told LiveScience. "They are capitalizing on others' awareness and actively probing that awareness."
This kind of ripple mimicry effect is often termed a “contagious display.” Hare and colleagues note in their paper that contagious displays exist in other species as well. Humans may not routinely jump up and yip if we see someone else doing it, but we will usually yawn or laugh in response to seeing someone else doing the same. Primates and even dogs have been known to catch yawns from each other as well.
“Emotional contagion among humans has been considered at least an important precursor to more advanced ‘Theory of mind’ abilities” – a sort of philosophical precursor to empathy, which allows a being to attribute distinct desires, beliefs, and mental states to others – “wherein contagion represents the first step toward respondent awareness of the emotional state of the instigator by invoking that same state in the respondent,” the authors write.
Hare and colleagues want to further explore the prairie dogs’ jump-yip phenomenon, to see how various individual characteristics affect their behavior. Are certain prairie dogs more likely to join in the wave than others? Does the direction of the wave matter – can it direct a prairie dogs’ attention towards potential threats?
Perhaps you can consider these questions and more during your next halftime stadium wave.
SOURCE: Hare et al. “Catch the wave: prairie dogs assess neighbours’ awareness using contagious displays.” Proceedings of the Royal Society B published online 7 January 2014.