A new study reveals that canines use both visual and cognitive cues to identify others of their species, no matter how different the breeds.
Louise’s daughter asked her an interesting question one day while they were walking their dog. The friendly golden retriever had just stopped to say hello to a passing pug. “How does Kiefer know that’s another dog?” the little girl asked. It’s a good question, especially when you consider the huge physical diversity of different breeds.
According to veterinarian Dr. Dominique Autier-Derian of theNational Veterinary School in Lyons, France, dog breeds show the largest morphological variety of any animal species, which means visual recognition represents a true cognitive challenge for individual canines.
For example, compare a great Dane, mastiff, Chihuahua, and an Irish wolfhound. Given the huge differences between these breeds in size and shape, not to mention coat type, color, and muzzle length, they don’t look like they’re even from the same species. Unlike wolves, foxes, or other wild canines, domestic dogs present a huge phenotypic diversity. With so much variation in size, shape, and appearance, how do dogs know when they’re interacting with other dogs?
In any social interaction, dogs need to first determine whether the other animal belongs to his own species. This can be done by smell, sight, and hearing, but it can also involve cognitive processes such as discrimination and categorization. In a recent innovative study, Dr. Autier-Derian found that usingvisual cues alone, dogs are able to pick out the faces of other dogs (regardless of breed) from other animal species, and group them into a category of their own.
Nine adult dogs (five females and four males owned by students at the National Veterinary School) took part in this study. Two of the nine dogs were purebred (one a Labrador, one a border collie), and seven were crossbreeds. None had the same morphotype in terms of form, color, marking, hair length, and ear type, whether upright or drooping.
All the dogs were between two and five years of age, had extensive prior experience of visual interspecific and intraspecific interactions, and basic obedience training. They also underwent ophthalmological and behavioral examinations.