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People interested in “dog smarts” often wonder if dogs make and use tools; recently I received a few emails inquiring about tool use by domestic dogs. While there are very few observations of dogs making and using tools, I'm sure they do and that they possess the cognitive capacities to perform these sorts of purposeful acts, and it would be useful for people to share their observations about their or another tool-using dog.
In their comprehensive book called Animal Tool Behavior: The Use and Manufacture of Tools by Animals, Robert Shumaker and his colleagues have a few stories about tool use by dogs, including a springer spaniel who used a frisbee to carry a hockey puck. And, there's an interesting video of a raven playing with a table tennis ball with a dog (with 13,829,061 hits and 6,314 comments) about which I just learned, a rare example of tool use for the purposes of play.
The video of the raven and the dog reminded me of something I saw at a local dog park a few years back. A large dog, Melvin, was trying to get a much smaller dog, Angus, to play with him, but Angus refused all of Melvin's invitations to play. Finally, Melvin picked up a piece of rope, dangled it in front of Angus, and then ran away. After around five such attempts to get Angus to play, Angus finally chased Melvin, they briefly played tug-of-war, and then they fell to the ground and wrestled and chased one another around tirelessly.
Clearly, the rope worked to break down whatever barriers there were, and it seems like Melvin was using the rope as a tool to get Angus to play. I realize that neither the raven nor the dog made the table tennis ball, and Melvin didn't actually make the rope. "Manufacturing" is one aspect of tool behavior that some researchers feel is necessary before one can call something true tool behavior (for more discussion please see "Crafty Crocodiles Use Sticks to Lure Prey and Zoo Problems"). However, both the ball and the rope were used to achieve a goal that seemed to be unachievable before they were used for a specific purpose.
The emails I received concerning tool use by dogs reminded me of a dog named Grendel who made a back scratcher that was fashioned out of a marrow bone. Grendel’s human friend, Lenny Frieling, told me the following story: It would have been about 1973 that Grendel made her first tool. Because of her short legs and long torso, she could not reach the center of her back to scratch. One day we gave her a bone that was likely sawn from a large leg bone, perhaps lamb, because it was quite hard. It was cylindrical, with parallel flat sides. About a week (at most) after we gave her the bone, we noticed that she had chewed it so that one side was still flat, and the other side had two raised ridges (shaped like a sine wave going around the outer rim of the bone). She would place the bone, flat side down, on the floor, and roll over onto the two raised ridges using the protrusions to scratch the center of her back. I was convinced that she had made a tool, but in my mind, I thought that behavior had to be repeated to be scientifically significant. She had that first bone, as I recall it, for quite a while, maybe a year. It disappeared. We gave her another bone and within days, or a week, she had carved the second bone into a very similar shape and used it for the same purpose. She had repeated the making of the tool.
There's also a video called "Beagle won't be denied chicken nuggets" that caught my attention because of the careful planning shown by a beagle in search of chicken nuggets in a toaster oven. This quest, dubbed "Operation Nugget Liberation," clearly shows this dog trying different strategies to get the food and then figuring out how to do it. The dog's adventure is described as follows:
Step 1: Move the chair into position using paw to push along kitchen floor.
Step 2: Leap onto chair and then onto counter, with an elegant one-two punch. Note: Be careful not to disturb any of the other countertop appliances.
Step 3: Make way past sink to toaster oven. Open oven with paw. Wait a minute. Is the oven on? You don't care. You want nuggets.
Step 4: Knock entire tray of food to ground. Eat, eat, eat.
Step 5: Practice "ashamed" face. When family forces you to watch video of your misdeeds, use ashamed face.
A dingo named Sterling also has been observed to use a similar strategy, and the video of his actions is well worth watching.
Some of the numerous comments accompanying the beagle's quest for chicken also mention various forms of tool manufacture and use by dogs.
It's wonderful to learn about more and more examples of tool use by various animals, including crocodiles because these observations can form the basis for future non-invasive experiments that can be enriching for the animals being studied. Cleverness in tool manufacture and use is clearly widespread among diverse animals, as shown by the numerous examples in Dr. Shumaker and his colleague's book (please also see Tool Use in Animals: Cognition and Ecology) and observations by citizen scientists.
As I wrote above, it would be very useful for people to share their observations about their or other tool-using dogs. Tool behavior tells us a good deal about the cognitive capacities of nonhuman animals, and there still is so much to learn about what they think and know.
References
Smith, B., Appleby, R., & Litchfield, C. Spontaneous tool-use: An observation of a dingo (Canis dingo) using a table to access an out-of-reach food reward Behavioural Processes, 2011. DOI: 10.1016/j.beproc.2011.11.004.
