London, Oct 23 (ANI): A new study has shown that dogs rely on seeing their owners' faces in order to recognise them.
The researchers also measured how much dogs prefer to gaze at and follow their owners, rather than a stranger.
The team described how dogs had difficultly recognising their human "best friend" when the person had their face covered.
The study sheds more light on how thousands of years of domestication have affected the behaviour of canines.
Paolo Mongillo from the University of Padua said that, although many researchers have studied how dogs interact with humans, no one had yet investigated how the animals focused on one person in preference to another - or just how much companion dogs "prefer" their owners.
"We had the dog in an empty room and we instructed the owner and another person - someone unfamiliar to the dog - to walk across the room several times," the BBC quoted Mongillo, lead author of the study as saying.
"The people walked in opposite directions, so they crossed many times in front of the dog and we measured how long the dog looked at one person versus another," he said.
The research team then instructed the two people to leave the room via two different doors and allowed the dog to approach one of the doors.
"Most of the dogs gazed at their owners for most of the time and then chose to wait by the owner's door," said Mongillo.
In the second part of the study, the scientists asked the people to cover their faces; the human volunteers then walked across the room with bags over their heads.
During this phase of the experiment, the dogs were much less attentive to their owners. This revealed just how much the animals relied on human faces for recognition.
Wild dogs rely on body signals and on cues from other animals in their social groups, but studies including this one suggest that domestic dogs are so attuned to human social groups that they are even able to recognise some human facial expressions.
"This is very likely to be a by-product of thousands of years of domestication," said Mongillo.
In the same study, the team investigated the effects of ageing on the dogs' attention.
They found that "aged" dogs - seven years and older - were less able to focus on their owner and also were less likely to choose the owner's door.
The findings appeared in the journal Animal Behaviour. (ANI)