Forgotten species: the subterranean Gekko gigante

Jeremy Hance
mongabay.com
April 08, 2010



Everyone knows the tiger, the panda, the blue whale, but what about the other five to thirty million species estimated to inhabit our Earth? Many of these marvelous, stunning, and rare species have received little attention from the media, conservation groups, and the public. This series is an attempt to give these 'forgotten species' some well-deserved attention.

Travelers to tropical destinations are likely familiar with the gecko. Clinging to walls and ceilings of buildings—sometimes staring down at you from the bedroom ceiling or glancing at you quizzically from the bathroom door—the small adhesive-footed lizard could be aptly described in some tropical areas as ubiquitous. Despite the apparent commonness of some species, geckos are delightful lizards with round wide eyes, a thick gripping tongue, and of course that amazing knack of seemingly defying gravity with specialized toe pads.

But not all geckos are as easily found—or as common—as those hanging out, literally, in a jungle lodge. The Gekko gigante, also known as the Gigante narrow-disked gecko, has been little- noticed by the public. Even scientists know little about the lovely gray-and-blue gecko beyond the fact that it lays its eggs on cool moist cave walls in two Philippine Islands.

In fact, the species is so cryptic that it doesn't even have the honor of its own Wikipedia page. Meaning that all 172 episodes of the subpar Star Trek: Voyager television show have their very own Wikipedia page, but our living, breathing Gekko gigante does not.


No, this photo is not upside down, the Gekko gigante was caught hanging upside down in its cave habitat. Photo by: Pierre Fidenci.
Because it lives deep in cave crevices, the Gekko gigante successfully avoided discovery by science for a considerable time. First noted by scientists in 1974, the Gekko gigante has yet to be assessed by the IUCN Red List as to its conservation status. But considering its small range—two islands—and its specialized habitat—caves—it's likely that the gecko's population is tiny, according to Pierre Fidenci.

"It is currently found in two small islands (North and South Gigante Islands) and its occupancy is roughly 3-4 km². Both islands are inhabited by roughly 5,000 people mostly fishermen living along the coastline," explains Fidenci to mongabay.com

Fidenci is the president of Endangered Species International (ESI) and has spent a lot of time in the Philippine seeking little-known species, such as this subterranean gecko. ESI also often focuses on species that have been largely ignored by big conservation groups.

One of a few people to see and photograph the Gekko gigante, Fidenci says of his first encounter: "[the Gekko gigante] was about 15 meters inside a cave […] I thought its head was similar to caiman since I saw it from an unusual angle!"


Another view of the Gekko gigante. Photo by: Pierre Fidenci.
Much has changed on the islands, however, since the cave-dwelling gecko's discovery in the mid-70s.

"Both islands have already lost significant forest coverage and remaining natural forest is mostly found in area difficult to access like in karst limestone outcrops," says Fidenci.

An account in Haring Ibon by Rafe M. Brown and Angel C. Alcala describe the forest loss in detail: "What remains is scrubby and stunted vegetation. With the forest gone, conditions on Gigante changed as they have throughout most of the Philippines’ previously forested low elevation areas: water became scarce as the local microclimate turned arid. The absence of shade trees makes the ground hot and dry, and the rainy season erodes the topsoil into the porous limestone beneath."

But at least for now the endemic gecko seems to have survived the island's changes, probably due to its preference for caves. But given its tiny range it is unlikely the Gekko gigante is thriving. In fact, threats may come from an unexpected source: tourism.

"Human population growth on both islands and increase in the number of tourists are the main threats to this species in the future," explains Fidenci. "Any disturbance or change to the caves, rock crevices, or rocky environment could dramatically impact the survival of the gecko. The caves are attractive and can be walked deep making them a destination for tourists. Another threat includes future mining activities that could negatively impact this species."

Unlike many little-known endangered species, protecting the Gekko gigante probably wouldn't be difficult or costly. It would just take the will to do so. For example, Fidenci recommends "protecting most caves and restricting their visits". In addition, he says that "conservation awareness on both islands is an important part of the conservation strategy as few people are aware of their unique biodiversity and the need to protect it. Dynamite fishing and illegal cutting of trees still occur on both islands, so we have a lot of work to do in term of education and awareness."


View of South Gigante Island. Photo by: Pierre Fidenci.
Another step forward would be further the research of the Gekko gigante. Fidenci says research is especially needed on "home range and habitat associations."

Visitors to either of the Gigante Islands should educate themselves about the islands' unique biodiversity which also include the Gigante frog and do everything they can to mitigate their impact, according to Fidenci.

"[Tourists] should avoid visiting caves and disturbing rocky environments. Caves are home of endemic and endangered species and they constitute a main physical characteristic of both islands for wildlife. If they cannot resist visiting them, they should do in a very small group along with local officials to avoid any impacts. [The Gekko gigante] should be observed from a distance," Fidenci explains, adding that "people can also support our group."

I'll add one final recommendation to the list: someone should give the Gekko gigante its very own Wikipedia page.




Entrance to cave harboring the Gekko gigante on South Gigante Island. Photo by: Pierre Fidenci.




Approaching South Gigante Island. Photo by: Pierre Fidenci.




The deforested landscape of South Gigante Island. Photo by: Pierre Fidenci.




The Gekko gigante. Photo by: Pierre Fidenci.




The Gekko gigante. Photo by: Pierre Fidenci.







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CITATION:
Jeremy Hance
mongabay.com (April 08, 2010).

Forgotten species: the subterranean Gekko gigante.

http://news.mongabay.com/2010/0408-hance_fs_gekkogigante.html