It's good to bark

Barking as a way for dogs to communicate with humans

source: Kate Douglas
New Scientist vol 182 no 2451, June 12 2004
starts p 552, 2 pages long

Humans and dogs have lived close to each other for between 15,000 and 30,000 years, and communication between the two species may have developed in this time. Barking was once seen as having little meaning, but it may be that it uses similar patterns to human speech, giving humans a greater ability to understand dogs than our ability to understand other species.

Barking is not apparently used much as a way for wild canids, like jackals, foxes and wolves, to communicate with one another. They do communicate with sound, for example, howling and whining, but generally it is only used by juveniles when they play. Dogs were thought to bark as a result of preserving juvenile traits.

Research by Dorit Feddersoen-Petersen, from Kiel's Christian-Albrechts University in Germany, has found that dog barks differ from those of wolves. Dogs have more variable barks, in terms of length, and in terms of having both harmonic and atonal sounds. Wolves tend to have short, atonal, gruff and low-pitched barks.

Dogs also bark differently according to context. They are likely to bark noisily and atonally when they feel physically distressed or socially insecure, while positive social interactions, like playing, seem linked to more harmonic barks.

Further research, this time from University of California Davis, backs this finding. Sophia Yin examined acoustical analyses for 10 dogs, and over 4,600 barks, focusing on three situations, a doorbell ring by a stranger, being isolated from the owner, and play. Low-pitched, harsh, rapid barks were linked to doorbells ringing, isolation was linked to high-pitched barks, and play to unevenly spaced, tonal barks.

Meanwhile, Adam Miklosi, from Budapest University, Hungary, has found that humans are able to guess the reason for why a dog is barking, even if the humans are non-dog owners. His study used 10 herding dogs, mudis, which are notoriously vocal, and 90 humans, one group of which owned mudis, a second of which owned other breeds, and the third did not own dogs at all. The humans assessed the dogs' barks for emotions, such as happiness, aggression, fear, despair, or playfulness, and were also asked to link the bark to one of a choice of seven situations. The humans guessed the situation correctly around a third of the time, and had an accuracy rate of around 45% when they categorised barks. This level of accuracy is better than could have been achieved by chance, and all three human groups performed well. Humans seem to have an innate ability to understand dogs.

Mammals may have some acoustical patterns in common, argues Cornell University's Michael J. Owren, and he goes on to note that his research shows how cats can meow in a way that attracts owners' attention. The trait of being able to communicate in this way may have been selected for in both cats and dogs. Dogs have even greater abilities than cats, since their repertoire is greater, and they can vary volume, pitch, tone, duration, and the length of time between one bark and another.

Miklosi is unsure as to whether humans selected this trait of being able to communicate in dogs, but humans do appear to be able to infer a range of messages that dogs send us. Dogs are less dumb than some people think.