Jan
09
How rattlesnakes’ scales help them sip rainwater from their bodies – Headline Science


During storms, some rattlesnakes drink rain
droplets from scales on their backs. This unusual behavior could help them survive
when water is scarce. Now, researchers have figured out how the
nanotexture of scales from these snakes helps them use their bodies to harvest rain. They report their results in in ACS Omega. The western diamondback rattlesnake (Crotalus
atrox) has been spotted emerging from its den to harvest rain, sleet and even snow. The snake flattens its body and often forms
a tight coil, presumably to maximize its surface area for gathering water. As rain droplets coalesce on its back, the
slithery reptile sucks water from its scales. Gordon Schuett, Konrad Rykaczewski (pronounced
“Rake-a-chev-sky”) and colleagues wanted to take a closer look at rattlesnake scales
to determine what makes these serpents so good at harvesting rain. The researchers studied the impacts of single
droplets of water on a rattlesnake’s back. An initial droplet split into smaller droplets,
which beaded up and coalesced on the snake’s scales. In contrast, droplets striking the backs of
two other desert-dwelling snakes, the desert kingsnake and the Sonoran gopher snake, formed
shallow puddles that slipped off the snakes’ bodies. These species have not been observed harvesting
rain. Scanning electron microscopy of rattlesnake
scales revealed nanochannels that form a labyrinth-like network. Scales from the other two snakes lack these
nano-features. Video footage of a droplet evaporating from
the rattlesnake’s scales showed that water penetrates into the nanochannels, pinning
the droplets to the scales. These findings indicate that the rattlesnake’s
scales aid in water collection by providing a sticky, hydrophobic surface that pins water
droplets to the surface, the researchers say.