Jan. 16 (UPI) -- To the surprise of scientists, wolf puppies learned to play fetch in response to verbal cues from a human researcher. The unexpected phenomenon was described this week in the journal iScience.
Dogs are thought to be unique in their propensity to interpret and respond to human cues, but while testing and observing the behavior of wolf pups, researchers were surprised to find the untrained puppies spontaneously retrieved a ball in response to verbal commands.
"I watched the test in real time from another room. In the first two litters the two first years of the study, none of the wolves showed interest in the ball," lead researcher Christina Hansen Wheat, a behavioral ecologist at Stockholm University in Sweden, told UPI in an email. "I did not think much of it at the time, but when we tested our third and last litter in the third year of the project, and I saw the first wolf puppy retrieving the ball, I literally got goose bumps. It was so unexpected."
The litter consisted of several eight-week-old puppies, hand-raised by Wheat and her colleagues from the age of 10 days. The researchers responsible for raising the puppies were not present during the tests. The puppies took interest in a ball and returned it to a complete stranger upon encouragement.
Wheat and her colleagues are interested in studying the effects of domestication on animal behavior. Responsiveness to human cues was thought to be one of those effects.
"It has been hypothesized that due to the close companionship with humans over the past 15,000 years, at least, dogs have evolved unique skills in understanding human social cues," Wheat said.
The latest discovery suggests some base level ability to interpret human cues is latent in wolves.
"While wild wolves will bring back food to puppies in their pack, retrieving a ball for a human presents a very different context in which the wolf has to interpret social cues given by another species -- a human -- and then subsequently choose to cooperate based on these cues," Wheat said. "Retrieving for a human has never before been shown in wolves."
Scientists don't know yet how common this ability is. While surprising, authors of the paper suggest an ability to engage with and respond to verbal cues could have been advantageous for wolves during the earliest stages of domestication.