This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
What lizard species has been wiped out in its natural habitat and now depends on three breeding females breeding in captivity for its long-term survival?
Oh wait, I can't quite answer that, because the species has no official name.
For now it's being called the orange-tailed skink. It was only discovered in 1995 and to date has not been fully described. Although it doesn't have an official name, it has been given a temporary scientific name, Gonglyomorphus c.f. fontenayi, because it is similar ("c.f.") in appearance to the Macchabe skink (G. fontenayi). Until recently the species lived only on Flat Island in the Republic of Mauritius, the tiny, remote island nation in the Indian Ocean located 870 kilometers east of Madagascar. Unfortunately, plans to develop Flat Island for tourism brought a different kind of guest, the highly adaptable Indian musk shrew (Suncus murinus), which has been called one of the world's most damaging invasive species.
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Luckily, a field team from the Durrell Wildlife Conservation Trust noticed the invasive rodent-like mammals on Flat Island in 2010 and quickly gathered all of the skinks that they could find. Nearly 400 of the tiny reptiles went to Gunner's Quoin, an island nature reserve located between Flat Island and the main island of Mauritius. Another 22 went to Durrell's headquarters in Jersey, England. Those translocations were completed just in time: When Durrell staff returned to Flat Island in 2011, they found no evidence that any of the skinks remained. "Despite very sensitive equipment being used to survey the island, there were no skinks left," says Rick Jones, Durrell's communications officer. "Were it not for the forward thinking of our field team, the orange-tailed skink would be another statistic on the list of 40 known species that have become extinct in Mauritius since 1600."
It's too early to know if the skinks that were moved to Gunner's Quoin will survive or thrive, but the tiny population in Jersey is already growing. Even though the original 22 skinks included just three females of breeding age, they have over the past four months been on an egg-laying frenzy. Already 16 eggs have hatched and four more are incubating.
Creating a safe habitat where the skinks could breed required mimicking the natural environment of Mauritius, Jones says. "We have to establish the microclimate of just under the soil–substrate where the skinks live." This included matching the temperature above- and belowground, as well as varying the temperature and humidity levels. "It's extremely tricky, and requires a good routine to ensure that the right 'season' is biologically 'on time' for the animals," he says. "It comes with experience and a certain amount of gut feeling, but a daily routine of misting/spraying and pouring water into certain areas, and use of lamps for heat and UV."
Jones credits the small team led by Matt Goetz, Durrell's new head of herpetology, for creating and successfully managing the captive environment. "It's very much his instinctive methods of husbandry, born of a lifetime of interest, that has facilitated such success in breeding what is to all intents and purposes a species that could have disappeared before anyone even knew it existed."
With luck, the three females might soon be joined by other breeders. Goetz suspects that some of the younger skinks—specifically those approaching the 2.5-to-three-year-old range—might start reproducing when Durrell simulates a warm wet season.
It's too early to tell what further impact the invasive shrews might have on Flat Island, as the species is "very hard to counteract," Jones says. As for the skinks, they typically consume arthropods and other invertebrates, serving as prey themselves for larger snakes and birds. They also help keep soil turned over and refreshed, helping deliver fresh nutrients to plants. It is not yet known what will happen to Flat Island's ecosystem without them.
For now, though, at least some of the orange-tailed skinks from the Indian Ocean are safe in the England. Who knows, someday soon they might even get a name of their own.
Photo: Orange-tailed skink hatchlings the size of a match, courtesy of Durrell Wildlife Conservation Trust