As we walk along the wooded trail, Sage, a one-year-old male German Shepherd, uses a neck bite to push Sam, a four-month-old Labradoodle, to the ground. Sam jumps toward Sage, who once again flings the pup to the ground. Sam lies on his back wildly kicking his legs in the air while Sage bites down on Sam’s neck and growls. Sam finally wriggles free, only to be pinned again a few seconds later. Sam and Sage repeat this pattern of interaction over and over for about ten minutes, until we realize that if they keep it up, we will finish the two-mile loop around midnight. We need a quick solution, so we let Sage carry a tennis ball — his favorite thing in the world. Eureka! It seems to work, except for one glitch. Sam keeps running after Sage and leaping on him as if to say, “Leave that ball alone and come play with me!”
Sam and Sage are friends — best friends, in fact. Although it might strike some as anthropomorphic to describe their relationship in these terms, scientists have been documenting friendships in wild animals for over 30 years. First described in nonhuman primates, friendships have now been reported in a wide variety of mammals, ranging from giraffes to bottlenose dolphins. Friends are defined as individuals who, by choice, spend a lot of time near each other and frequently engage in friendly behaviors. Behaviors vary by species: Baboon friends groom a lot, bonobo friends have recreational sex, female dolphin friends “hold fins” as they swim together, and dog friends tend to play.
Over the past decade, we and our colleagues have been collecting video data of dogs interacting with each other. We have filmed hundreds of hours of adult dogs, juveniles and puppies at dog parks, on walks and in backyards and living rooms, including our own. We code these tapes frame by frame in order to scientifically address questions about play and other social behaviors in dogs (findings to be discussed in future articles). Along the way, we have documented, on tape and in notes, a number of striking canine friendships.
The relationship between Sage and Sam illustrates several important features of dog friendships. To begin with, canine friendships, by definition, are mutually preferred and jointly constituted. Sam was a puppy when he first met Sage on that walk five years ago. Since then, Sage and Sam have been exposed to many dogs, and a few of them have become friends of one or the other, but their relationship remains very special — and it was special right from the start. Not many dogs can take Sage’s rough play style, and to some outsiders it might seem like Sage is bullying Sam, but Sam relishes it and is fully complicit in their lopsided play pattern.
We have noticed that close canine friends often play roughly and develop idiosyncratic games. For example, Safi and Osa (female German Shepherd and male mixed-breed who were best friends for five years) often chased each other through the woods until they ended up on opposite sides of some huge log. Then, facing each other, they would bark back and forth as loudly as possible, interspersing the barks with nasty, lipcurling snarls. After 20-30 seconds, one would leap over the log toward the other and the chase was on again.
To a naïve observer, the play of good friends might look or sound like mortal combat. In reality, their wild games reflect how comfortable they are letting go with each other.
The Sage/Sam and Safi/Osa relationships clearly have important benefits for the dogs and also for us. The friends don’t live together, but they often visit each other’s homes. This can offer a great alternative to a kennel or leaving a dog home alone all day. While together, they tire each other out and stimulate each other’s bodies and minds. At the end of the day, living with a dog who has some of his social, physical and mental needs met is easier and much more fun.