Washington, Apr 30 : A new study has shed new light on dog communication, by showing how clearly dogs recognize and perceive the messages they get in form of different barks.
The study led by Peter Pongracz, professor of animal behaviour at Eotvos Lorand University in Budapest, Hungary found that dogs can perceive difference between barks arising from different situations.
"Dogs express basic emotions, and we have not yet found signs for more complex meanings, like 'this is the postman,' 'this is the bill collector,' 'this is the neighbour,' etc," Discovery News quoted Pongracz, as saying.
Previous studies had shown that people could certainly distinguish between different types of barks, however it was unclear how dogs could do the same.
For the study, the researchers hired pet dogs of different breeds from training schools, to serve as listeners and recorded the barks of Hungarian Mudi dogs in two different situations. In the first when a stranger entered the property where a given dog lived and the second, when the dogs were tied to a tree and left alone.
An electric drill and a refrigerator were taken as control sounds. The team also monitored the heart rates of listening dogs.
The dog barks increased the heart rate of a listening dog and hearing a certain type of bark time and again stabilized the heart rate.
However, they could get used to the distress barks, the listening dogs always showed a jump in heart rate when the team switched from one type of recorded bark to the other.
The change in attentiveness shows that not all barks sound the same to other dogs.
The researchers believe that dogs recognize the different contexts producing the barks they hear.
"We think barking existed in the ancestor of the dogs, but the present form of variability and abundance of barking is the product of domestication in dogs," said Pongracz,
He further added that domesticated dogs must have later "learned how to use barking amongst each other" as a form of communication to go along with others, such as visual and scent cues.
The study will appear in the journal Applied Animal Behaviour Science.