Why forked tongue

See more words from the same year. Accessed 11 Nov. Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free! Log in Sign Up. Save Word. Definition of forked tongue. First Known Use of forked tongue , in the meaning defined above. Owls use their asymmetrical ears in this way to detect sound in three dimensions.

Snakes and owls use similar neural circuitry to compare the signal strength delivered from each side of the body and determine the direction that a smell or a sound is coming from. Humans do this with their hearing too, but not as effectively. This makes it possible for snakes to follow trails left by their prey or potential mates.

These results were refined and confirmed during the s. In the s, snake biologist Neil Ford at the University of Texas at Tyler watched how male garter snakes used their tongues when they were following pheromone trails left behind by females.

However, when one tip or the other fell outside the edge of the trail, the snake turned his head away from that tip and back towards the pheromone trail, and his body followed.

Following this simple rule allowed the snakes to perform trail-following behaviour that was both accurate and directed. If both tongue tips ever touched the ground outside of the trail, the male would stop and swing his head back and forth, tongue-flicking, until he relocated the trail. Snake ecologist Chuck Smith at Wofford College found evidence that male Copperheads have longer, more deeply-forked tongues than females , which presumably enhances their ability to find mates.

But in the case of snakes, Schwenk thinks the forked tongue plays several roles. As with lizards, the tongue can lead the snake to prey. It can also help young snakes find dens for winter hibernation by following scent trails left by adults on their way to the den.

And adult male snakes use the tongue to zero in on pheromones produced by female snakes. The male snake can judge from the intensity of the smells on each fork which direction a prospective partner went — and find his way along the trail until he catches up with her, Schwenk says.

This action allows them to sample odor molecules from two widely separated points simultaneously. Fork-tongued lizards, the legged cousins of snakes, do something very similar. But snakes take it one step farther.

Unlike lizards, when snakes collect odor molecules in the air to smell, they oscillate their forked tongues up and down in a blur of rapid motion. To visualize how this affects air movement, graduate student Bill Ryerson and I used a laser focused into a thin sheet of light to illuminate tiny particles suspended in the air.

We discovered that the flickering snake tongue generates two pairs of small, swirling masses of air, or vortices, that act like tiny fans, pulling odors in from each side and jetting them directly into the path of each tongue tip.