Listening in on third-party conversations is impolite. But it’s one way that humans and some non-human animals gather information to help them live well with their fellows. But does cross-species eavesdropping happen? If it does, can our pets eavesdrop on us?
Researchers at the Universities of Milano and Parma allowed 84 dogs to “eavesdrop” on human conversations—kind of.
First they asked owners to hold their dogs on short leashes while the dogs listened and watched food-sharing interactions among three humans. One human played the role of a “beggar,” repeatedly approaching two potential “donors,” who were each holding a bowl of food. Always, one donor would firmly reject the beggar, both vocally and with strong hand gestures of the sort many dog owners use when telling their dogs “No!” The other beggar would willingly share the food. Then the beggar left the room and the dog was let off leash.
Now, remember: Both donors were holding bowls of food. But the dogs usually approached only one of them—the donor who had been willing to share with the beggar. Clearly, the dogs had noticed the quality of the interactions between humans. But which aspect of the human conversations had they really taken in? The words? The hand gestures?
The researchers repeated the experiment twice—once without words and once without hand gestures. And it was the vocal communications that had more effect on the dogs. In other words, dogs clearly prefer generous humans, and they learn which ones are generous by their spoken conversation.
Note: While this research suggests that dogs eavesdrop on human conversations, there is no evidence yet that they gossip about us.
TAILS—THE LONG AND SHORT OF IT
Dogs bark and growl, but they also “talk” with their tails. Furious wagging signals happiness. A tail between the legs shows submission. In some breeds, a tail pointing straight ahead means “the prey is over there.” And so on.
So what about tail docking—the cosmetic practice of cropping a tail very short for breeds like boxers. Would cutting off a dog’s talking tail be a little bit like cutting out a human’s tongue? It makes some sense for hunting dogs. For them, collecting burs in their tail can lead to infections. But what about show dogs, or just plain old pets? Wouldn’t that handicap the dog, making it nearly impossible to communicate non-barking statements about fear, playfulness, or caution.
The effects on dog communication of tail cropping nor docking was examined in Canada in 2008 … Researchers put a robot dog with a very short tail in an enclosure and let him interact over time with almost 500 off-leash dogs. No matter how hard he wagged a very short tail, other dogs didn’t notice. When the experimenters re-fitted him with a long tail and had him wag it, other dogs interacted with him.
So, yes, cropping or docking the tail of a dog effectively ruins one huge aspect of his ability to communicate. Yet breeders and veterinarians routinely dock the tails of dogs younger than 2 weeks without anesthesia. In a relatively old study in New Zealand—1996—of 100 veterinarians and 100 breeders, no veterinarians, but 25% of the dog breeders believed that docking was painless. And in another New Zealand study in 1996 researchers systematically observed the behavior of 50 puppies during and after the docking procedure. All puppies shrieked intensely at the time of amputation, averaging 24 shrieks each. Then they whimpered an average of 18 times. Thirty seconds after the amputation they began to quiet down. On average, the pups stopped crying a little more than two minutes after the amputation. All puppies were quiet 15 minutes after the procedure. Yikes.
DOES THIS DOG MAKE ME LOOK FAT?
Um … no. But in 2012 researchers in England studied whether owning a dog would help pregnant women avoid becoming obese. Analyzing data collected in the 1909s they found that women who owned dogs were more likely to walk actively and really work up a sweat at least 3 hours a week than women who didn’t have dogs. And of course brisk exercise has more health benefits than just avoiding weight gain. But the researchers found that owning a dog had little to do with whether an expectant woman gained more weight than she should.
Oh, too bad.
Photo credit Katie Tegtmeyer http://www.flickr.com/photos/katietegtmeyer/