The giant Tongan ground skink was a remarkable creature, and one with a storied history. Stealthy, solitary and elusive–this lizard, endemic to the Tongan Islands of the South Pacific–was rumored to have special powers by native Tongans. It was said that, when a tribesman spotted the rare, 1.5 foot, sleek-grey predator, something portentous would occur–possibly a funeral.
The species was first documented to science between the years of 1826 and 1829 by two French scientists, Jean-Renee-Constant Quoy and Joseph Paul Gaimard. Quoy and Gaimard traveled aboard the Astrolabe, an exploration ship of the French navy, as it circumnavigated the globe. The naturalists collected the only two specimens of the giant skink in existence, which are now housed in the Paris Natural History Museum.
The species, Tachygyia microlepis, is listed as extinct in the IUCN Red List of Threatened Species. However, a new paper, authored by scientists Ivan Ineich and Wolfgang Bohme, suggests that the giant skink may still be living in remote areas of Southern Tonga.
“We believe T. microlepis is still alive in southern Tonga and should in particular be searched for in the ‘Eua National Park, which hosts the last remaining rain forest of this area,” state the authors. “It could also occur on the small Kalau Island located south of ‘Eua.”
The original specimens were found on Tongatapu Island. However, deforestation, along with the introduction of cats, dogs and rats to the island, likely caused it to go extinct. At present, Tongatapu has been 90% deforested.
In 1986, British naturalist John Gibbons offered a reward of 100 Tongan dollars to anyone who could find or photograph the famed skink. His inquiry, which he published in the local Tongan newspaper, turned up no results. Tragically, Gibbons and his family died in a boating accident while attempting to cross the reef at Lakeba in Fiji, before he could return to Tonga and resume his search for the lost species.
The remaining forest area of Tongatapu, comprising only 3% of the entire island, was surveyed in 1993 by scientists George Zug and Ivan Ineich. They, too, were unsuccessful in finding the grey-ghost.
But hope remains. One reason for optimism comes from another extinct–and subsequently rediscovered–species of skink: Bocourt’s Terrific Skink or the terror skink. This skink, endemic to the islands of New Caledonia, was thought to have perished for the same reasons as the giant Tongan ground skink. However, two specimens were collected in the early 2000s in the Isle of Pines, a small island group slightly south of the main island of New Caledonia.
Another reason for optimism comes from the stealthy nature of the grey ghost. The authors believe that the original discovery, by the French naturalists aboard the Astrolabe, happened during the rainy season when the skinks were forced out of their underground lairs by heavy rains. Gibbons also theorized that the skink lived underground and was active only at night or after very heavy rains. This account squares with Tongan folklore suggesting that sightings of the skink were rare and, thus, portentous.
Time will tell whether the elusive skink still exists on the islands of Tonga.
“We believe this [giant Tongan ground skink] to be unlikely to survive on the ecologically heavily compromised island of Tongatapu,” confirm the authors. “However, it may still persist on some peripheral islets or on the large and less ecologically altered island of ‘Eua that still retains some primary forest.”
