A Question For You

Can anyone tell me what they think about this? 
I have a question but no answers, and am curious to hear your thoughts and ideas.
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Today I was riling up our male Greyhound, jabbing him on the tush then dashing away in the dog park, getting him to bark and chase after me. 

After a few kickstarts he normally takes off on his own in grand looping circles or figure eights, at top speed. (I’m sure because he’s completely bored of my “running”, which to him is nothing but a lackadaisical lope!)

It is beautiful to watch.

Awhile ago I began to notice a particular behavior, body-language, that he does when he’s happy, playful, usually running. It consists of a head-bobble, side-to-side. Not like shaking the head “No”, but more like how one of those bobble-head dolls bounces, tipping right and left, not swiveling.

He does it always with a huge smile, and only when he’s running toward me and we make eye-contact. It says to me: “I’m goofing around here! This is awesome! Come and get it! Goobly-googly let’s go!”
In the past few months I’ve started to try to kickstart his bobble-head behavior by running toward him laughing and bobbling my own head side to side. (Yes, I tend to have no shame in the dog park, or for that matter in any interaction with dogs. A philosopher named “Diogenes” considered dogs’ shamelessness to be a primary virtue; but that’s for another post.) And it works! I start it; he responds in kind. 
Even before those experiments – but bolstered by them – there is now no doubt in my mind that the bobble is a conscious, if not intentional, enjoyable add-on to our boy’s running and playing. He is perfectly capable of running and playing without doing it; in fact most of the time he does. It is meant to convey an emotion. It is an expression, a means of communication. Something that must have been biologically selected for.

Unfortunately I have no videos of it. These pics are the best approximation I can offer. If you look from pic to pic you might get a vague sense of the wobble. I hope to have videos of it soon, but it is always a brief and difficult moment to capture.

My main question is:  Has anyone else witnessed this kind of behavior? In their dog or anyone else’s? I own every book on dog body-language that’s ever been written, and seen most every video about dog behavior and psychology there is. But I’ve never seen this filmed, described, or even mentioned. I’ve seen it clearly, often, and can even induce it. Our girl Greyhound doesn’t do it. I’m wondering if any other Greys do it? Or any female Greys? Or possibly other breeds? If you’ve seen this let me know! 
My secondary question is:  What does it mean? Maybe this is a boring question: it means he’s happy and playing. Even if that’s the case, I wonder Why does it mean that? Most dog behaviors and expressions are intended to have a causal consequence, either in other dogs or in their humans. And it is usually based on something biologically, developmentally, etiologically, evolutionarily based. Something that has a relevance “in the wild”. For instance, baring teeth is threatening because it displays to a potential predator your defense mechanism. “Soft eyes” communicates peacefulness and trust, because half-closed eyes see less and so are less defensive, more relaxed. And so on. If this head-bobble isn’t just a figment of my imagination (which I’m convinced it isn’t), where did it come from? Why does it mean what it means, and how did it evolve?
Any comments, thoughts, or random related stories will be greatly appreciated!
Happily yours,
The Calm Energy Bobblepack
Published On: October 17th, 2011Categories: Yelp