Role of Scale Wettability on Rain-Harvesting Behavior in a Desert-Dwelling Rattlesnake.
ACS OMEGA 2019;
4:21141-21147. [PMID:
31867507 PMCID:
PMC6921647 DOI:
10.1021/acsomega.9b02557]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 11/15/2019] [Indexed: 06/10/2023]
Abstract
During storms in the southwestern United States, several rattlesnake species have been observed drinking rain droplets collected on their dorsal scales. This process often includes coiling and flattening of the snake's body, presumably to enhance water collection. Here, we explored this rain-harvesting behavior of the Western Diamond-backed Rattlesnake (Crotalus atrox) from the perspective of surface science. Specifically, we compared surface wettability and texture, as well as droplet impact and evaporation dynamics on the rattlesnake epidermis with those of two unrelated (control) sympatric snake species (Desert Kingsnake, Lampropeltis splendida, and Sonoran Gopher Snake, Pituophis catenifer). These two control species are not known to show rain-harvesting behavior. Our results show that the dorsal scales of the rattlesnake aid in water collection by providing a highly sticky, hydrophobic surface, which pins the impacting water droplets. We show that this high pinning characteristic stems from surface nanotexture made of shallow, labyrinth-like channels.
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