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5 December 2013 11:26 am ,
Vol. 342 ,
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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ScienceShot: Just Joking! Dogs' Play Growls Exaggerate Their Size
20 September 2013 5:00 pm
Dogs present themselves differently to other dogs depending on whether they’re protecting their food or goofing around. That’s the conclusion of a new study by scientists at Eötvös Loránd University in Budapest, Hungary. They let dogs choose between photos of two other dogs, while simultaneously playing a recording of either a food or a play growl. (The play growls were made while owners engaged in tug-of-war with their dogs; these animals were not included in the experiment.) One photo was of a dog whose size matched the growl, which reflects the length of a dog’s vocal tract; the other was of a dog either larger or smaller than the growler. When the listening dogs heard the food growl, they focused on the image of a dog who was the size of the growling dog. But when they heard the play growl, they fixed their eyes on the photo of the bigger dog, even though the growl was made by a smaller one, the scientists report in the current Applied Animal Behaviour Science. Dogs give an honest growl when guarding their food, the scientists believe, because a beagle, for instance, might be injured if it decides to play retriever. But a small dog making an “I’m really a BIG dog" growl during play likely knows that the other animal can see its size, and recognizes that it’s essentially making a joke. Dogs likely use the fake growls as they do their other exaggerated play behaviors, the researchers suggest—to reassure each other that the rough and tumble play is, after all, just a game.