Dogs Have Growls For Every Occasion

When a dog talks to you the growl can mean many different things. A new study suggests that dogs have different growls for different occasions and what is more surprising is that other dogs can tell the difference.

An example of this is when a dog is playing and makes a growl, that sounds quite difference to when a dog is growling in reaction to a threatening stranger. When scientists played back the recorded sound of these two types of growls to other dogs, those dogs behaved differently depending on which growl they heard.

Peter Pongracz of Eotvos Lorand University in Hungary says what is particularly interesting about the finding is there was proof that dogs understand one another through vocalization. A few other species have hinted at this ability including monkeys, however it is largely unproven in the animal world.

“We’ve researched a lot about how dogs communicate with humans, and how humans communicate with dogs, but how dogs communicate within the species is fairly new,” Pongracz said.

The researchers recorded growls from as many as 20 fully mature dogs in three different context. In one situation the dog was kept on a leash and given a meaty bone. In another situation the dog was recorded playing tug of war with its owner and in a third situation the researchers had another dog try and snag the bone from the owner which would result in a guard growls. The final scenario involved holding the dog on a leash whilst an adult male stranger approached silently, continually staring at the dog which provoked a threatening growl from most of the dogs.

The scientists recorded growls from 20 adult dogs in the three different situations. During the playful situation, the dog and its owner played tug of war. In another situation, the dog was kept on a leash and given a large, meaty bone. Then the researchers had another dog try to snag the bone, triggering the meat owner to react with a “guard” growl. (Both dogs were held on leashes by their owners, and no dogs were hurt). Finally, the owner stood behind the dog and held its leash while a 25-year-old male stranger approached slowly and silently, continually staring at the dog. This prompted a threatening growl from many of the dogs.

Mr. Pongracz says there was a major difference between the play growl and the two other growls which he says the researchers called agnostic. Play growls tend to be higher pitched and shorter in length. However what was most interesting is the researchers were unable to find significant acoustic differences between the two agnostic growls.

Whilst the scientific equipment and the researchers were unable to tell the difference, the dogs seemed to be able too. When the scientist replayed their recordings to see if other dogs reacted any differently they found that the growl associated with food guarding was far more effective than any of the other growls at deterring other pooches who were thinking about stealing an unattended bone.