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| Photo: Holly Kuchera / Shutterstock |
Eleven wolves and fourteen dogs took part in the study. They were hand-reared in similar conditions, and all were taught basic obedience such as sit, down, and how to walk on a leash. They were tested at 4, 5 and 7 months of age.
The study took place in a meadow. A dead chick was used as food in the experiment. Each wolf or dog was held on a short leash while a demonstrator (human or canine) put the chick in one of three locations. Then they were released on a 10m long line to explore as they wished. Each trial ended after the chick had been found or two minutes had elapsed, whichever was soonest.
In two other conditions, the demonstrator (human or canine) walked to one of the locations and back without a chick. This was a ‘pretend’ scenario to check the animals were paying attention. In a control condition, the chick was hidden prior to the animal arriving, and there was no demonstration; this tested whether they could find it by smell alone.
Because the handler had a dead chick in her pocket during these three conditions, she also had to have a dead chick in her pocket during the dog and human demonstrator conditions, so that this would not be an extraneous factor.
The results showed that both dogs and wolves were more likely to find the dead chick in the meadow if there was a demonstrator. In all five conditions, dogs were more likely to find the chick than wolves, though it is not clear if they were better at it or more motivated.
There was a significant difference between dogs and wolves in the demonstrator conditions. Dogs performed equally well whether the demonstrator was a dog or a human. However, wolves performed much better when the demonstrator was human. In fact, the wolves did not pay much attention to the dog demonstrator, whether it really hid the chick or just pretended to.
The fact that both wolves and dogs did better when there was a demonstrator shows they used visual information, and not just smell, to locate the chick. The scientists say, “Although it is clear that canines have an extraordinary sense of smell, little is known regarding in what situations they actually use olfactory cues if not specifically trained to do so.” A recent paper by Alexandra Horowitz et al (2013) is a fascinating first step in understanding the sense of smell of ordinary pet dogs.
In the control condition both dogs and wolves sometimes found the chick, showing they could use their sense of smell to locate it. Interestingly, they did less well at this when they were 7 months compared to younger. Another difference as they aged was that they spent longer watching the demonstrations. It’s not clear if this is because – by this time – they had prior experience of the experimental set-up and had learned the demonstrator would be hiding food. It could also be a developmental difference, or that they simply had more experience with both dogs and people at this point.
The wolves were better at finding the chicks following a human demonstration. It is hard to interpret the results in terms of domestication, however. Dogs were more attentive to the human control trials, which could be because they have evolved to pay more attention to humans. Or it might be that the wolves had a better understanding of causality, and did not pay attention to a human with no food because they knew nothing was in it for them.
The scientists say, “Interestingly, the wolves were less interested in the dog demonstration than the dogs even when the demonstrator had a chick in its mouth, whereas both groups paid similar attention to the demonstration in the dog control trials. This result is in contrast with our expectations based on the domestication hypothesis… the wolves went to the end point more often in the human demonstration trials than in any of the other three conditions. This suggests that they paid special attention to the human demonstration also when compared to the dog demonstration.”
Although there are several possible explanations, the ones the scientists deem most likely are that the wolves have a better understanding than dogs that food comes from humans, or that the wolves were sensitive to signals from the demonstrator dogs. It turns out the demonstrator dogs “did not like to take the dead chicks in their mouths and clearly showed their resistance by turning their head or trying to spit the chick out.” The wolves may have recognized these signs of disgust, and hence been less interested in the food.
If the experiment was repeated, it would be a good idea to use a food item the demonstrator dogs do not object to. It’s unfortunate they were asked to do something they did not like, particularly since the paper states that the dog and wolf participants were given a choice as to whether or not they took part. The researchers say they used dead chicks because "the animals are highly motivated to obtain them," and obviously it has to be an item the demonstrator dogs are trained to drop and leave behind.
The study shows that both dogs and wolves can use information from a visual demonstration to find food, but wolves had most success following a human demonstrator. These findings potentially contradict the domestication hypothesis, but because there are several possible explanations, more research is needed.
Does your dog pay attention when you are doing things with food, such as cooking or eating?
Reference
Horowitz, A, Hecht, J, & Dedrick, A (2013). Smelling more or less: Investigating the olfactory experience of the domestic dog Learning and Motivation, 44 (4), 207-217 : http://dx.doi.org/10.1016/j.lmot.2013.02.002 Range, F., & Viranyi, S. (2013). Social learning from humans or conspecifics: differences and similarities between wolves and dogs Frontiers in Psychology, 4 : 10.3389/fpsyg.2013.00868
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