spermophilus_beccheyi_000.jpg        Why, by night, in front of a rattlesnake, the California ground squirrel (Spermophilus beecheyi) straightens up his tail and waves it like a feather duster ?  By filming the scene in infrared, Aaron Rundus, (University of  California), noticed that the tail’s temperature increased probably because of an impulse of blood. The snake, sensitive to these infrared, thinks that the squirrel is much more bigger and so he beats a retreat. This stratagem could be very useful for the Spermophilus beecheyi female to protect her young . On the contrary, in front of a viperine snake, unable to detect his prays with heat, the squirrel waves his tail to, in order to impress the snake. But he doesn’t go to a lot of trouble to heat it.

In front of a viperine snake, the tail remains “cold” (blue on the video)

In front of a rattlesnake, the tail becomes “warm” (red on the video)

~ by elevenbears on October 2, 2007.