The Lost Lizard of La Désirade: An Extinction We Almost Forgot About
By John R. Platt
Most tourism sites use a common word to describe La Désirade Island in the French West Indies: "pristine." They rave about this 8-square-mile island's beautiful beaches, abundant wildlife, snorkel-worthy waters and healthy nature reserve.
In truth, this small rocky outcropping in the Guadeloupe Islands has seen its fair share of human-driven change since colonial settlers arrived. Once a haven for pirates hiding out from the law, the island served as a colony for lepers and lawbreakers for two centuries. The land, despite its modern reputation and protected status, was heavily cultivated and disturbed for much of that time — much like the other islands around it.
"There's no 'pristine' environment when it comes to the Guadeloupe Islands," says Corentin Bochaton, a postdoctoral researcher with Université de Bordeaux in France and the Max Planck Institute in Germany, who conducts studies in the archipelago. "These islands were all strongly impacted by European colonization starting in the 17th century. La Désirade is nowhere close to what it was before this period."
He points out that research published 15 years ago links that disturbance to several local extinctions — and now, thanks to his work, we can add one more to the list.
According to a paper published last month in the journal Zootaxa, La Désirade was once home to a unique lizard, a relative of the curly-tailed iguana-like lizards common to the West Indies. The authors, including Bochaton, have dubbed it Leiocephalus roquetus.
Long forgotten by science and the residents of La Désirade, the evidence of L. roquetus was hiding under our noses — and La Désirade's soil — for nearly two centuries.
The first line of evidence for this lost lizard's existence has sat on a shelf for most of that time — since 1835, in fact. And like La Désirade, it was far from pristine.
"Around 2015 we consulted on a very old and rather poorly prepared stuffed specimen of Leiocephalus indicated as originating from Guadeloupe," Bochaton recalls. The 10-inch-long taxidermied lizard came from naturalist named Théodore Roger, who deposited it at the Natural History of Museum of Bordeaux in France three years before his death in 1838. The original label has been lost to time, but a mid-20th century replacement identifies the specimen as Holotropis herminieri (a species named by scientists in 1837 and later moved into the Leiocephalus genus) from the vague location of "Guadeloupe."
Bochaton points out that L. herminieri, another extinct species last seen in the 1830s, lived on the island of Martinique, also in the West Indies. Despite the "Guadeloupe" label the specimen did, indeed, bear external anatomy suggesting it was the Martinique species. "Because of that, it was never studied in detail," he says.
It's easy to see why the specimen was ignored for so long. While previous research had indicated a need to reassess the species in the Leiocephalus genus, at least seven of the 24 previously known species are long gone and the supply of specimens or bones to study were, until recently, slim.
A northern curly-tailed lizard (Leiocephalus carinatus) on Cat Island, Bahamas. Photo: Trish Hartmann (CC BY 2.0)
That's where new archaeological evidence came into play. Bochaton and others have conducted numerous digs in the Guadeloupe Islands and uncovered hundreds of lizard bones from days gone by. The most successful excavation took place in 2018 at a cave on La Désirade, where they found what Bochaton calls "the largest assemblage of Leiocephalus bone so far in Guadeloupe."
Like the museum specimen, which the researchers examined through CT scanning, those newly uncovered bones contained enough common morphological differences to declare it a new species, one that hasn't been seen on La Désirade or any other Guadeloupe island since…well, no one knows when. Perhaps since Roger's time.
Exactly how and when this species went extinct remains a mystery, but the paper suggests it could have been a combination of "introduced mammalian predators, human-induced changes to landscapes and intensive agricultural practices."
And while we may not know what killed off the lizard, Bochaton says the evidence of its extinction has relevance to modern times.
"To me, this highlights the rapid damages modern societies and their agro-pastoral practices have caused to insular ecosystems and shows what might also happen in the long run in more resilient continental systems," he says. This could help us learn to prevent more extinctions in the future.
Meanwhile, he hopes it will help to inspire more research and protection in the region.
"There are still several questions that remain poorly explored in the Guadeloupe islands regarding its past fauna, especially for the periods preceding the arrival of human populations," he says. "I hope that this research will motivate the public and the government to do their best to save the remaining Guadeloupe and Lesser Antillean endemic reptile fauna by highlighting how fast and easy it is to lose and completely forget an endemic species that will never come back."
And speaking of short-term memories, La Désirade's official tourism site calls the island itself "The Forgotten" — a name that might now equally apply to the creatures we caused to vanish there before we even knew they existed.
John R. Platt is the editor of The Revelator.
Reposted with permission from The Revelator.
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