For all the talk about dogs being man’s best friends, we still understand surprisingly little about them. Part of that stems from the fact that dogs and humans have been intertwined for thousands of years. This means we’ve meddled in their evolution, which makes it hard to figure out what traits of dogs emerged naturally and what traits were selected by humans over the centuries. Take human voices, for instance.

Dogs can recognize human voices — or rather, familiar human voices. But that makes sense if your survival depends on the people who feed you and you meet often. So it could be that dogs simply evolved this way because of their interaction with humans.

Dogs who were better at recognizing human voices had an advantage over those who didn’t. This seems to make sense. Otherwise, why would you care enough to distinguish the voice of an ape-like creature?

But a new study challenges this idea. The study looked at wolves, dogs’ closest relatives. Wolves were never domesticated, so they didn’t have this incentive. If wolves had the ability to distinguish human voices, it would suggest that dogs also had this before they started mingling with humans.

As it turns out, this is exactly the case. Wolves also recognize familiar human voices, just like dogs.

What’s up, wolves?

Holly Root-Gutteridge of the University of Lincoln wanted to see how wolves would react to familiar voices.

She and colleagues set up an experiment across five zoos and wildlife parks in Spain, involving 24 wolves aged 1 to 13. They basically set up speakers and habituated the wolves to the voices of strangers. From the same speakers, they played the voices of the wolves’ keepers, who the wolves were familiar with. The voices would say things like “Hey, what’s up wolves?” or “Hello little ones, good morning, how’s it going?”.

Initially, the wolves were curious about the strangers’ voices, but they quickly lost interest. But when they heard their keepers’ voices, it was completely different. They reacted in a way that would be familiar to all dog owners. They raised their heads, pricked their ears up, and turned towards the speaker. Then, once more, the researchers would play the strangers’ voices — and once more, the wolves were not interested.

Overall, wolves only reacted to human voices that were familiar to them.

The findings confirm that wolves do pay attention to familiar human voices and this isn’t a feature acquired through domestication and selection. But, while this study has helped further our understanding of wolves, it also opens up new possibilities for broader cross-species communication. Basically, the implications go beyond just humans, wolves, and dogs.

Cross-species communication

Wolves and humans have a common ancestor but you’d have to go back over 100 million years to find it. We both went our own evolutionary ways long ago. So why then, is one species attuned to the other’s voice?

Previous research had shown that gorillas are attuned to human voices, but that’s not surprising. Not only are humans and gorillas closely related, but primates in general are thought to have more refined social abilities. Elephants also exhibit remarkable abilities. Not only can they recognize familiar voices, but they can distinguish between the voices of men, women, and children. They also distinguish between the elephant-spearing Maasai than the agrarian Kamba. But this probably comes out of practical interest: men are more likely to be a threat to the elephants, as are the Maasai, so it’s useful to recognize them.

Does this also mean that wolves have an interest in distinguishing human voices? Or is this rather an innate ability? Perhaps even more intriguingly, what other species can understand us and know us as individuals? If cross-species communication is more common than we thought, there could be a lot of different creatures with this ability.

It’s not all about us, either. Your dog could be able to distinguish the neighbor’s cat’s meow, or your cat could be able tell apart the friendly neighborhood dog from an unknown potentially dangerous dog.

This research, while primarily focused on wolves, provokes an exhilarating question: Who else in the animal kingdom is truly listening and to what extent can they comprehend? The answer could be a game-changer in our relationship with the natural world.

Journal Reference: Beatrice Gammino et al, Grey wolves (Canis lupus) discriminate between familiar and unfamiliar human voices, Animal Cognition (2023). DOI: 10.1007/s10071-023-01796-9.