European colonizers caused the extinction of 50% to 70% of snakes and lizards in Guadeloupe, a new finding that illustrates the devastating impact of colonialism on life.

For the study, published Wednesday in Science Advances, researchers analyzed 43,000 reptile-bone remains from six islands that make up part of Guadeloupe, a French department in the Caribbean Sea. The islands have a rich fossil record, and it was clear that successive Indigenous peoples — the most recent of whom, the Kalinago, were largely slaughtered and expelled by France in the 1600s, after more than a century of resisting colonizing powers — coexisted with these reptiles for thousands of years without incident. 

After 1635, the French relied on enslaved Black people to turn the islands into sugar plantations and grazing land — intensive agriculture on the islands is less than 400 years old. Still, the 32,000-year-old fossil record showed that many lizards and snakes on the islands survived potentially catastrophic climate change but did not survive the arrival of white people. 

At least eight species and four genera went locally or completely extinct, including the lizards of the genera Pholidoscelis, Leiocephalus and Diploglossus, as well as boas of Guadeloupe. 

"The wipeout of Amerindians, slavery of African people and destruction of natural environments served the same goal: to transform Guadeloupe into a giant crop field in order to make money for the state and [a] few rich settlers," said Corentin Bochaton, an associate post-doctoral researcher at the Max Planck Institute for the Science of Human History and the lead author of the paper. Bochaton said the data he and his co-authors gathered "can help to better understand extinction processes and design conservation plans."

The study looked at fossils from 31 sites across six islands of Guadeloupe. The researchers found 16 different taxa of lizards and snakes — "the term taxa can [refer] to a species, a genus or a family, depending on the animal we talk about, as the bones in the fossil record can be difficult to identify with precision," said Bochaton, who is also a post-doctoral researcher at the Centre National de la Recherche Scientifique. On all the islands, there were 31 to 45 extinctions in the last 458 years, including extinctions of local populations. The researchers identified at least 62 insular populations overall.

"Humans are still greedy, and the destruction of natural environments is still ongoing in the area, still for the benefit of few and at the expense of most people," Bochaton said.

Environmentalists and researchers have been raising louder and louder alarms about the destructive effects of intensive agriculture. Despite the fact that current food systems harm biodiversity and are responsible for air pollution that kills 15,900 people a year in the U.S. alone, agriculture is often left out of international and U.S. climate plans. But this study of the past in Guadeloupe provides fresh evidence for the importance of including sustainable farming in conservation efforts. 

Notably, in the 1700s, the French led an effort to clear nearly all the forests on the islands. The island with the earliest and most widespread agricultural intrusions by the French, Marie-Galante, had the worst extinctions: Over 70% of taxa that used to live there were gone.

The evidence in this study also indicates the cost of invasive species: Both tree-dwelling and smaller species seemed to have survived better, leading the researchers to hypothesize that cats and mongooses introduced by European colonists wreaked havoc on medium-size species. This information can be used to better target conservation efforts. 

Nicole Boivin, a co-author who is the director of the department of archaeology at the Max Planck Institute for the Science of Human History and an honorary professor at the University of Queensland, said that history is key to understanding how to map out the future. 

"The way that colonialists treat people and ecosystems are extremely related," Boivin said. "There was an orientation of commodification towards the world. … I do not think it is an accident that the bloody and exploitative European era also featured a massive transformation of landscapes. And while we have, at least to some degree, rethought how we commodify other people, we have yet to do so nearly as effectively with respect to nature."

Boivin also noted that the findings show not only that European settler-colonialism causes mass death but also that living more harmoniously with nature is possible. 

"There is a tendency in some conservation approaches to equate conservation with ridding the land of all people or preserving untouched habitats," Boivin said. "This has negatively impacted Indigenous and local populations and led to some conflict between conservation efforts and Indigenous rights. … Our paper encourages this trajectory by highlighting that people does not necessarily imply destruction, that there are many ways of living in and with nature."

The paper, "Large-scale reptile extinctions following European colonization of the Guadeloupe Islands," published May 19 in Science Advances, was authored by Corentin Bochaton, Max Planck Institute for the Science of Human History, Sorbonne Universités and Université de Bordeaux; Emmanuel Paradis, Université de Montpellier; Salvador Bailon, Sandrine Grouard, Ivan Ineich and Anne Tresset, Sorbonne Universités; Arnaud Lenoble, Université de Bordeaux; Olivier Lorvelec, Agrocampus Ouest; and Nicole Boivin, Max Planck Institute for the Science of Human History, University of Queensland, Smithsonian Institution and University of Calgary.