Clarion nightsnakes have been found on a volcanic island off the coast of Mexico, exciting biologists, who believed the species was extinct. The animals have not been seen by humans in 80 years.
The nightsnakes were re-discovered on the Mexican island of Clarion, located in the Pacific Ocean.
Daniel Mulcahy, a researcher from the Smithsonian Institution, led an expedition to the island. Working in cooperation with the Mexican Institute, the biologist found 11 animals on the island which matched the description given by an American naturalist, William Beebe, in 1936. Examination of DNA from the animals revealed they were genetically distinct from other snake species on the island.
Nightsnakes were first discovered by Beebe when he collected one member of the species for examination, returning home from the island with the sample. These dark brown snakes with darker spots are well-camouflaged among the black volcanic rock of Sulphur Bay. Fully-grown individuals can stretch as long as 18 inches from tip to tail.
"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," Mulcahy said. They retraced Beebe's footsteps to discover the nocturnal snake, which is secretive and blends into the black volcanic rock.
Biologists believe the snakes are most-closely related to species native to the border between the Mexican states of Sonora and Sinaloa. Ancestors of the species may have evolved in Sonora, and then traveled to the island from a river basin.
The species was never declared officially extinct, despite remaining unseen for eight decades. Still, the species was seldom recorded in biological journals or textbooks. Part of the reason for this is the remote nature of the island. The area is only accessible with military escort, which greatly reduces the number of biologists who visit Clarion.
For scientists who did visit the island, the animals remained hidden from view, until now. In 1955, a team traveled to Clarion Island, collecting samples of animal life from the remote outpost of land, 625 miles from the coast. The nightsnake could not be found, and many biologists believed that Beebe made a mistake recording the location of his discovery.
These snakes are facing a distinct threat from feral cats on nearby islands. The felines prey on lizards, which biologists believe are a staple of the nightsnake diet.
"Island ecosystems are particularly vulnerable to invasive species and other ecological disturbances. Properly documenting historic and current species distributions is critical for quantifying extinction events," Mulcahy and his team wrote in an article, detailing their find.
Re-discovery of the nightsnake was detailed in the online journal Plos One.
