![Dogs](/https/www.telegraph.co.uk/content/dam/news/2024/06/03/TELEMMGLPICT000380342634_17174372356000_trans_NvBQzQNjv4Bq-ayPyDIFkRmcmHVmPD-v21x4rCqpdUIWTeh-etGfXsA.jpeg?imwidth=680)
Why are flat-faced dogs so yappy? Answer lies in change from their wolfish ancestors
Breeds with poorer facial communication, such as brachycephalic dogs, are more vocal than longer-nosed breeds, scientists find
![Dogs](/https/www.telegraph.co.uk/content/dam/news/2024/06/03/TELEMMGLPICT000380342634_17174372356000_trans_NvBQzQNjv4Bq-ayPyDIFkRmcmHVmPD-v21x4rCqpdUIWTeh-etGfXsA.jpeg?imwidth=680)
Flat-faced dogs such as pugs and French bulldogs bark and yap more because they have lost the ability to communicate effectively with people visually.
Wolves, the ancestor of dogs, have long noses and facial muscles which produce expressions that are easy for people to understand.
However, selective breeding to create specific types of dog has reduced this ability in pet canines, a study has found for the first time.
Dogs vocalise more than wolves to make up for the facial expression shortcomings, data show. Breeds with poorer facial communication, such as brachycephalic dogs, are more vocal than longer-nosed breeds.
Pet dogs have also adapted by evolving bigger eyebrow muscles to enhance puppy dog eyes, scientists say, which may further aid communication.
The domesticated animals still have the same facial muscles as wolves but they are smaller, more cramped and often covered up with fur or flaps of skin.
Muscles have become smaller
“Domestic dogs have not lost any muscles but due to breeding for specific facial features, such as brachycephalic faces, the muscles have become smaller and more compacted together, giving them less room to move to produce the same facial expressions as wolves and wolf-like dogs,” Elana Hobkirk, a canine behavioural ecologist who led the study at Durham, University told The Telegraph.
“In addition, features such as long flopped ears and pendulous lips mask the movements of the face and limit the ability to produce the same facial expressions seen in wolves.”
She added: “It is more difficult to discern facial movements in brachycephalic compared to wolf-like dogs. We provide evidence that dogs with more limiting facial features actually vocalise more than wolves and wolf-like dogs in any given social context.”
The scientists filmed dogs and wolves and found nine specific behaviours that can be seen in both species: anger, anxiety, curiosity, fear, friendliness, happiness, interest, joy and surprise.
More than 500 people were asked what state a wolf was in and people were best at identifying curiosity (94 per cent correct) and worst at joy (46 per cent).
They were able to determine which mood a wolf was in with 71 per cent accuracy but this figure dropped to 65 per cent for dogs.
Those surveyed performed worse for dogs overall, with only 6 per cent correctly identifying fear. The easiest mood to identify was friendly but one in four were still unable to spot this.
Ms Hobkirk said people often mistake fear for anger or friendliness in dogs and this poor inter-species communication could lead to dog bites and attacks.
Fear confused with friendliness
“Fear being confused with anger is not great for social communication (either dog-dog or human-dog) but at least that is a negative emotion confused with another negative emotion,” she said.
“Fear confused with friendliness is a negative emotion confused with a positive emotion, which is detrimental for dog-dog and human-dog communication. If a human perceives a dog as being friendly, when in reality the dog is trying to display fear, that human could be bitten by the dog.”
The change from wolves to dogs is more pronounced in extreme breeds who have faces starkly different to their wild ancestors, data show, and domesticated animals are adapting by using their voices and their eyes more.
“Dogs are bred to vocalise (bark mainly) more than wolves, especially for pastoral breeds as they herd and protect livestock,” Ms Hobkirk said.
“However, pastoral dogs tend to have more wolf-like faces, and despite this, the dogs with the more non-wolf-like faces in our study actually vocalised more in comparison to wolves, and in comparison to the more wolf-like dogs.
“This suggests that the vocalisations have evolved as a means to compensate for a lack of facial communication brought about by selective breeding.”
The study is published in the journal Scientific Reports.
The wolf-like expressions used by dogs
Anger: Eyes wide open with inner-brow raised, ears up and forward facing, nose wrinkled with upper lips raised, and lower lips depressed, teeth are bared. The wolf will vocalise (growl), and a jaw snap may occur. Sometimes mouthing/biting at social interaction occurs.
Curiosity: Ears are up, left and right head tilting occurs and sniffing.
Friendly: Eyes can be wide with inner-brow raised, lots of blinking and eye closure can occur also, submissive grin is performed (lip corners are pulled back and sometimes teeth are shown), ears are back flat against the head, whine vocals occur and tongue flicking.
Interest: Ears up and forward, head often bobs up and down, sniffing occurs.
Anxious: Air is sucked in through the lips creating cheek depressions, sniffing occurs and whimper vocals.
Fear: Eyes are wide with inner-brow raised and the whites of the eyes can be seen, the mouth will be partially open, ears are back flat against the head and the head will often be lowered.
Joy: Lip corners are pulled back, jaw drop occurs, ears are forward and sometimes mouthing at social interactions occurs (not biting).
Surprise: Eyes are wide and inner-brows are raised, ears are up and forward (mouth appears tight).
Happy: Eye blinking and eye closure occurs, can sometimes see whites of eyes, head is raised up and sometimes the tongue can be seen near the edge of lower teeth (not a tongue flick).