Saturday, February 7, 2015

A tale of a tail



Years ago, I’m not sure when, I accidentally broke off the tail of a gecko. I stepped on the tip of its tail and it broke of quickly and cleanly without a spot of blood. The gecko scampered off a bit lighter, while its severed body part remained behind, gyrating as if in the midst of a seizure. I stood there mesmerized and watched as this autonomous body part behaved like it was receiving rapid fire electronic shocks, which, in a way, it was.

Photo: TStone
For the first two minutes, the swishing  of the tail was spasmodic and continued on one side then the other, flipping over upside down again and again from the momentum. The action was not unlike how a caterpillar reacts when being attacked by ants, or a game fish flexes while fighting the ever-shortening line that leads to the bass boat. The tip of the tail curled far up one side and then the other, jerking rapidly with yoga-like dexterity.

By the third minute, the frantic gyrations were noticeably farther apart in frequency, slowing gradually and evenly. After another five minutes, the tail was still moving, but lethargically now, with longer pauses between movements. It would stop for a two or three seconds, then regain some strength and move quickly again a half dozen times, then stop and eventually start again with an even longer period between movements. After nine minutes, the movement was still active enough for me to keep counting the minutes on my watch, but my interest was waning.

By the eleven minute mark, there was barely any movement except for the very tip of the tail, twitching like a cat's as it contemplates a pounce. At a dozen minutes, it was a boxer in the final round, throwing drunk punches and stumbling from fatigue. By fourteen minutes, it was still moving but with five or more seconds between each twitch. The thicker end (the broken end) that hadn’t moved much was now making some subtle, noticeable movements, but the opposite tip had all but stilled. At the fifteen minute mark, there were a long seven or eight seconds between pulses. At this point, I started thinking more about what I had brought for lunch than indulging my scientific curiosity.

From the gecko's point of view, I acted exactly the way that was intended: I was so distracted by this disconnected flailing body part that the far more important half with the brain, legs, vital organs, and reproductive potential was able to make a successful getaway. And that, it did.

Kim Stone