Garter Snakes Form Surprisingly Strong, Human-Like Friendships

Snakes come in all shapes and sizes. Some don't even have scales. But one thing they all have in common is a reputation for aloofness. They're often seen as lone operators, the solo artists of the reptile world.

But new research suggests that reputation may be unearned — at least for garter snakes, which are proving to be surprisingly social creatures. A recent study published in the journal Behavioral Ecology and Sociobiology, suggests they form strong bonds with others of their kind. And they prefer to spend their time with friends, rather than alone.

"Our research demonstrates that these snakes actively seek out social interaction and prefer to join and remain with larger groups and that their social interaction patterns are influenced by consistent individual differences in boldness and sociability," the researchers note in the study.

To reach that conclusion the researchers — psychologist Noam Miller and graduate student Morgan Skinner of Wilfrid Laurier University in Waterloo, Ontario — looked at the way 40 eastern garter snakes interacted with each other.

The young snakes were placed in four enclosures in sets of 10, with each marked with a distinct colored dot on its head. At two points in the day, the researchers emptied the enclosures of snakes and thoroughly washed each area before putting them back inside. But each time, they put the snakes in different positions.

Would the snakes find each other again and rekindle their connection? Indeed, cameras installed in the enclosure tracked them doing just that — forming hangouts of three to eight snakes, most often consisting of the same members. No matter how many times the snakes were put in different locations, they managed to seek out the company of their old friends.

The researchers concluded that they had formed cliques — social structures that "are in some ways surprisingly similar to those of mammals, including humans," Skinner tells Science magazine.

What's more, Skinner and Miller noted some very human-like hallmarks of a snake's personality. For one thing, some were simply bolder than others. Each of the four enclosures, for instance, had a shelter with an open door allowing the snakes to wander into the wider world. When placed alone in the shelter, some snakes preferred to stay coiled up inside that shelter, evidently preferring safety over curiosity. Other snakes refused to stay pent up at home and boldly explored the world outside the shelter.

But when the snakes were with friends, their behavior changed, as distinct personalities dissolved into a kind of group-think. And that group tended to play it safe.

The researchers noted that the more snakes there were in the shelter, the less likely they were to leave it. Even individuals that had been bold in the past surrendered that aspect of their personalities to the group.

That's not to say the young garter snakes clung to each other just because they enjoyed the company. Like all reptiles, snakes are cold-blooded — they need the sun, and in this case, likely the bodies of their fellow snakes, to stay warm. In uncertain circumstances, snakes may also gain comfort from close proximity to one another, including the researchers note, some protection from predators.

But if there's a particularly enterprising snake among them — one that breaks away from the crowd to go exploring — it can report back that the wider world isn't so dangerous after all.

And maybe, just maybe, the crowd could be convinced to follow that snake.

"These results highlight the complexity of snake sociality and may have important implications for conservation efforts," the researchers note.