It's well known that chimpanzees, birds, and many other "smart" animals make and use tools. What we currently know about animal tool behavior has recently been reviewed in a wonderful book by Robert Shumaker and his colleagues, and the examples they show from a wide range of animals will surely surprise you. Now, we can add another animal to the long list of tool makers and users.
Bradley Smith of the University of South Australia and his colleagues working at Melbourne's Dingo Discovery and Research Centre have just published a paper showing tool use by Sterling, an 18 month-old male dingo. You can read all about this discovery here. The video is well-worth watching.
As described in their recent paper, "After several unsuccessful attempts at jumping for the envelope, Sterling 'solved' the task by first moving and then jumping up onto a trestle table (1.2 m × 0.6 m × 0.73 m) which allowed him to gain the additional height necessary to reach the food item. To move the table, Sterling clamped his mouth onto the strut between the legs of the table. He then walked backwards, dragging the table approximately 2 m, until it appeared that either his back leg or tail touched the enclosure mesh. He then jumped onto the table, but as he was still at least a body-length away from the envelope, he had to span the gap between the table and the enclosure mesh by propping his front paws onto the mesh gradually moving them towards the envelope. At full stretch, he reached the envelope on his second attempt."
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. The dingo study reminded me of a story I was told in 2002 about a dog named Grendel who fashioned a marrow bone as a back scratcher. 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 which 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 to 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."
I find these observations to be fascinating and as time goes on I'm sure we will continually add many animals to the already long list of tool makers and users.
The teaser image is of Stirling.