For most of us, commuting is a task to be endured. Busy, noisy and often cramped, the world’s underground transport systems are places that we humans tolerate as a matter of necessity. But not so for Moscow’s “metro dogs”. A number of strays have taken to riding the city’s underground railway – and remarkably, they seem to know where they’re going.

Of Moscow’s 35,000-odd stray dogs, about 20 are thought to travel regularly on the city’s underground rail system. These dogs seem to be able to identify which trains to board, and where to alight. It appears that they can recognise humans who will give them a treat or a pat – and avoid those who won’t. They also show an impressive ability to deal with the noise and activity of the busy metro system, which many pet dogs would find distracting and stressful – indeed, they can often be found relaxing and sleeping in the crowded carriages.

So how did Moscow’s stray dogs learn this behaviour? Well, dogs have co-evolved alongside humans for several thousand years. During that time, they have developed the capability to recognise and respond to our physical and emotional signals. While most animals have trouble interpreting the social cues of other species, dogs are unusually adept at responding to human behaviour. This evidence goes some way to explaining how Moscow’s metro dogs know who to approach and who to steer clear of.

These social skills strongly suggest a degree of convergent evolution between dogs and humans. This occurs when different species evolve similar traits while adapting to a shared environment. So, the abilities of the metro dogs might even suggest that they have developed coping mechanisms similar to those of their fellow human commuters.

But Moscow’s stray dogs have an even stronger motivation to venture into the metro system. Dogs learn through positive associations – this forms the basis for the modern reward-based methods we use to train both working and pet dogs. For example, we can teach a dog to “sit” on command by rewarding that behaviour with treats. These positive reinforcement strategies generate reliable and consistent responses from our canine companions, as well as safeguarding their welfare.

It seems likely that the metro dogs have learned to associate the subways with warmth and food. So the strays return, time and time again, much like the pet dog that repeatedly “acquires” dinner from the kitchen counter. For the metro dogs, the rewards of food and shelter are probably worth the risk of negative experiences, such as being shooed away, hurt or worse: one poor pooch, called Malchik, was stabbed to death in the subway, to the dismay of many Muscovites.

In this way, the metro mutts might serve as an interesting model for training pet dogs, since they show us that particularly powerful rewards will overcome incidental negative experiences.

No maps needed

Explaining how the metro dogs navigate the underground transport system is a bit more complicated. Given that the canine nose is substantially more sensitive than our own, it’s distinctly possible that they choose which stations to disembark at, based on scent. But studies suggest that dogs often use many sensory cues to find their way, and do not rely on smell alone.

So, the metro dogs probably use many indications including smell, lighting, passenger movement and perhaps even specific people to get their bearings in the subway. It has even been suggested that the dogs come to know the stations by name, by listening to the announcements over the tannoy. We know that dogs can learn words, so this is a possibility. But in this case, we can’t be sure whether the dogs genuinely know the names of specific stations, or simply associate some of them with food.

The final puzzle is how the dogs are able to time their journeys. This is a tough one, because it’s difficult to prove that dogs can even grasp the concept of time: many pet owners will receive identical welcome responses from their dogs, whether they have been absent for one minute or one hour. These observations suggest that dogs may perceive the passage of time very differently to humans.

Even so, many animals thrive on routine, and dogs are no exception. The regular goings on in Moscow’s metro – the opening and closing of stores, the peak hour rush and the system’s nightly shutdown – could be encouraging the dogs in their travels. The dogs are likely to associate these routine happenings with positive experiences, much like the excitement of a pet dog on hearing their owner’s car pull into the driveway after a day at work.

Moscow’s metro dogs represent an extremely interesting example of the domestic dog’s ability to adapt to a world built for humans, by humans. They show us that dogs have developed the capability to read human behaviours and respond accordingly, and to integrate themselves into our daily customs and practices. Understanding how dogs respond to the changing human world can help us understand both them, and ourselves, much better.

Jacqueline Boyd, Lecturer in Animal Science, Nottingham Trent University.

This article was first published on The Conversation.