Puff adders are stealth snakes that can remain motionless for several days as they wait for predators to pass and prey to approach. While it seems as though staying put would make the snakes an easy target to "sniff out," researchers from the University of the Witwatersrand (Wits) discovered the clever snakes have evolved an impressive visual and chemical camouflage that makes them virtually impossible to detect.

This African viper species, scientifically known as Bitis arietans, hunt by ambushing their prey. When annoyed, they often emit a hiss or puff sound – hence their name. Alternatively, the snake's main predators include honey badgers, warthogs, some larger birds and other snakes.

Unlike most snakes, howerver, puff adders spend most of their time on the surface, moving through grasses or other vegetation. Although their markings provide some form of protective camouflage, all that time above ground and out from under rocks out to make them detectable purely by their inherent scent, according to Wit's news release. Astonishingly, however, that's not the case at all.

Wits researchers who spent three years radio-tracking 30 puff adders in order to test the snake's visual and olfactory camouflage abilities, found the snakes have a unique protection method: the lack of a detectable scent. When dogs and tame mongooses were released in puff adder territory, both walked directly over motionless snakes, completely unaware the puff adders were present. Since dogs and meerkats, among other predators, rely primarily on their keen sense of smell to locate prey, researchers concluded puff adders must possess a form of chemical camouflage in addition to their visual camafloughe.

"These selective pressures have driven the evolution of not only their impressive visual camouflage, but, as we just found, also their chemical camouflage," Professor Graham Alexander, who heads the Alexander Herp Laboratory at Wits, explained in the release.

To confirm this hypothesis, researchers trained a team of dogs and meerkats to scent-match and test if they could detect puff adders. (Scroll to read more...)

"We asked the meerkats and dogs to scent-match scent samples collected from puff adders and other snake species. The scents of most snakes were easily identified by the dogs and meerkats, but they failed dismally when it came to puff adder scent," Wits post-graduate student Ashadee Kay-Miller added in the university's release.

Puff adders are reportedly the first terrestrial vertebrate species known to have evolved chemical camouflage. However, researchers believe their findings suggest this phenomenon is common among many ambushing species. But since olfaction is not the primary sense used by humans, not much research has focused on this aspect of biology.

The findings were recently published in the Royal Society Proceedings B.

Related Articles 

Praying Mantises Use 3D Vision To Hunt, Study Confirm

Threatened Australian Monitor Lizards Trained To Avoid Eating Toxic Toads

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

-Follow Samantha on Twitter @Sam_Ashley13