I've always been interested in play. Science doesn't explain it very well, or it's explained as something young animals do to practice future skills. But that definition doesn't cover every kind of play, and it doesn't explain why it's so much fun, so reinforcing in itself.
Helix Fairweather, a Karen Pryor Academy and ClickerExpo faculty member, is training a fish and posting videos of her progress on YouTube. She suspects her fish, Cartman, is playing when he bumps a springy plant leaf over and over. I think she's probably right.
You may remember the Oscar fish I taught to swim through a hoop years ago; the video is on the ClickFlicks website. When my fish grew big and had a big tank to live in, he liked to play. If visiting children put their noses against the glass, the fish put his nose against theirs on the other side. If they put their hands on the glass, he would put his nose to hands, too. The children could get him to swim from one end of the tank to the other by putting their hands on one end of the tank and then the other. There was no click or treat for this; as far as I can see, he just did it for fun.
How to play with an octopus or rhino
Natural History magazine ran an article about the giant Pacific octopus some years ago. One aquarium gave their big octopus a plastic childproof pill bottle with a treat inside to see if the octopus could get the lid off (octopi are good at that sort of thing). Since the bottle had air in it, it was buoyant.
Here's what the octopus actually did with the bottle. He held it up to the jet of clean water coming into his tank, let it go, watched it tumble across the tank, caught it, and put it back in the jet again. He did this over and over—he was playing! (The article made me feel that it might be really fun to train one of those guys!)
Here's a play story from Reaching the Animal Mind, now due out in February or March of 2009.
I'm at the Dallas Zoo, visiting the zoo's excellent rhinoceros collection. The keeper introduces me to her special favorite rhino, a half-grown male who was born at the zoo. The keeper shows me some of the rhino's husbandry behaviors. I enjoy the experience of personally moving him about with the target pole. The reinforcer is bits of banana, which he takes from my hand with gentleness and skill.
For this young rhino, however, the big reward at the end of a session is not food, but a game with the keeper. The keeper leaves the target, runs the length of her side of the paddock fence, and stops. Now she is the target. The rhino takes off at a run down his side of the paddock, screeching to a halt just as he gets abreast of the keeper. She turns and runs up the fence. He chases her back, tail in the air and little eyes sparkling. Of course, this is what young rhinos do! They play "Charge!"
People play, too. I think I'll go dig holes in my garden.
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