Your dog growls at you when you try to take away his food dish. Then he growls at you when you are playing tug with him. Can you tell the difference in the growls? Or does one growl sound like another to you?
It turns out, dogs can tell the difference between these two types of growls.
A study using 41 dogs of various breeds tested whether dogs can tell the difference between growling when another dog approaches food, growling when an unfamiliar stranger approaches, and growling while playing tug (Farago et al. 2010. This bone is mine: affective and referential aspects of dog growls. Animal Behaviour 79: 917-924 doi:10.1016/j.anbehav.2010.01.005).
The experimenters recorded dog growls in all three contexts. Then they played back the different growls to a dog approaching a bone. Here’s how it was done: a dog was allowed to approach an untended bone, and when the dog’s nose was close to the bone, the experimenters played back either a food guarding growl, or a threatening stranger growl, or a tug growl.
The results were striking. When the food guarding growl was played, 11 of 12 dogs withdrew from the bone. Compare this with the other growls: 2 of 12 dogs withdrew from the bone when they heard the threatening stranger growl, and 4 of 12 dogs withdrew when they heard the play tug growl.
Clearly, the dogs understood the meaning of the growls.
All three types of growls had different acoustic properties in terms of pitch and places where the most sound energy was concentrated (called “formants” in human language).
Interestingly enough, the food guarding growls and the threatening stranger growls were lower in pitch than the play tug growl. This is a common theme in aggressive vocalizations of many mammals: lower pitch (within the pitch range of the vocalizations that the animal makes) often means aggression.
Increasingly, scientists are finding that more and more animals have a language. To be fair to my scientific colleagues, most of them prefer to use the term “referential communication” rather than “language”. But I prefer to quote Shakespeare: “What’s in a name? That which we call a rose by any other name would smell as sweet.” And it’s sweet to know that scientific experiments are starting to show that dogs can smell the roses.
I had a german sheperd dog for many years. He occasionaly would growl at my teenage daughter when she approached him while he was eating. She would yell at him and tell us he couldn't be trusted. He did growl at me a few times and all I did was say 'stop that'. He did stop and now I wonder if my daughters reaction made him more agressive and/or did my non-reaction make the difference in food agression. I would like to hear what some have to say about it.
Posted by: Kathe Gruenthal | September 01, 2011 at 04:28 PM
We have a five year old poodle mixed with snoozer and he has all of a sudden started to growl at my husband as if he is going to bite him.It is just when he gets near me,maybe in my computer room or when I have gone to bed and he comes in to speak to me.He really gets furious.We have punished him by putting him in his cage but it is not helping.
Thanks!
Posted by: Georgia Mitchell | August 21, 2011 at 06:20 AM
Hi, Interesting post on dog growls. Dog communication is an interesting subject and dog owners should take note as it will help them immensely understanding what their growls mean.
The test example is great to show how dogs understand and communicate.
Keep the posts coming.
Jason
Posted by: dog behaviorist | January 18, 2011 at 03:38 PM