The Clarion Nightsnake (Hypsiglena unaocularus) – a nocturnal snake species that was initially discovered in 1936 and then struck from the scientific record – has been rediscovered by a team of U.S. and Mexican herpetologists.
The Clarion Nightsnake, Hypsiglena unaocularus. Image credit: Daniel Mulcahy.
The Clarion Nightsnake grows as long as 45 cm and has a distinctive pattern of spots on its head and neck.
This snake lives on black lava rock habitat near the waters of Sulfur Bay, on the Mexican island of Clarion, and is darker in color than its mainland relatives.
It was first discovered in 1936 by American naturalist and explorer William Beebe.
During more than a half of a century, herpetologists were unable to detect any trace of this species.
While never formally declared extinct, the snake remained absent from scientific literature due to two main factors: the snake’s home is extremely remote and only accessible by military escort, and the snake’s secretive behavior makes it difficult to detect in the field.
In May 2013, a team of herpetologists headed by Dr Daniel Mulcahy of the Smithsonian Institution’s National Museum of Natural History retraced Beebe’s steps in an effort to locate the lost species.
After an intensive search, they identified 11 snakes that matched Beebe’s description, and conducted a series of DNA tests to confirm that the Clarion Nightsnake is genetically distinct from other snakes located on the mainland of Mexico.
“The rediscovery of the Clarion Nightsnake is an incredible story of how scientists rely on historical data and museum collections to solve modern-day mysteries about biodiversity in the world we live in,” said Dr Mulcahy, who is the first author of a paper published in the open-access journal PLoS ONE.
“Proper identification is the first step toward conserving this snake, and we plan to continue monitoring this species to learn more about the role it plays in the delicate Clarion Island ecosystem.”
Dr Mulcahy and his colleagues studied the genetics, morphology and geographic distribution of several species of nightsnakes, and believe that the Clarion Nightsnake is most closely related to populations of snakes from in the Sonora-Sinaloa state border area of mainland Mexico and Isla Santa Catalina in the Gulf of California.
The species likely originated from the dispersal of an ancestor that traveled by sea from a river basin in Sonora to Clarion.
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Mulcahy DG et al. 2014. Rediscovery of an Endemic Vertebrate from the Remote Islas Revillagigedo in the Eastern Pacific Ocean: The Clarión Nightsnake Lost and Found. PLoS ONE 9 (5): e97682; doi: 10.1371/journal.pone.0097682
