RIO GRANDE VALLEY, Texas — Coiled beneath cloaking brush, this large Diamondback rattlesnake lurks in ambush for unsuspecting prey to wander by within striking distance.
Occasionally, the rattler flicks its forked tongue, as it tastes the air for scent, collecting odor particles that are transmitted into its Jacobson’s organ inside the roof of its mouth.
Something has alerted this rattler, and it twists its body around attempting to locate the source of stimulation.
Diamondback rattlesnakes are pit vipers and can detect thermal radiation or body warmth thru a pair of heat sensing pits on either side of their face enabling them to strike accurately even in darkness.
To compensate for relatively poor eyesight, rattlers can pick up vibrations through their body muscles, which send sound through to their inner ear organs, and since they do not have external ears they rely on these vibrations to discern sound.
Slowly, the impressive snake uncoils and begins silently slithering off into the undergrowth as it seeks out a new ambush site. As the rattler crawls it is constantly probing with its forked tongue, which it uses as a navigational aid. Depending on which side of the fork the presence of a particular odor is strongest enables the serpent to follow prey or sense direction.
Finally, the Diamondback uncoils its entire five feet plus length and with rattles held high and silently disappears into the chaparral.
Diamondback rattlesnakes are fascinating denizens of the brush country, and while they possess lethal venom they are unlikely to strike unless provoked.