21% of reptile species are threatened

According to a global analysis of 10,000 species, more than 21% of reptile species are threatened with extinction.

Less popular than mammals and birds, reptiles are under no less threat. This is evidenced by an analysis published in the journal Nature, the first in the world to look at this group of animals. It will be used to identify regions where conservation efforts are a priority.

To assess the status of reptiles (Vulnerable, Endangered, Critically Endangered), an international team of researchers relied on the International Union for Conservation of Nature (IUCN) Red List criteria. They found that 1,829 out of 10,196 reptile species, or 21.1%, are endangered. Crocodiles and turtles are among the most endangered animals.

This synthesis shows that the factors that weaken reptiles are, as for other classes, “agriculture, forestry, urban development, and invasive species. »

“Most endangered reptiles are found in regions of Southeast Asia, West Africa, northern Madagascar, the Andes and the Caribbean,” said Bruce Young, study co-leader and chief zoologist for environmental organization NatureServe, during a press conference. Contrary to what researchers thought, reptiles that inhabit forests are at greater risk than those that live in arid environments such as the desert. Forests that are threatened by the lumber industry and their conversion to farmland are becoming a less favorable environment for reptiles.

Millions of years of evolution

Madagascar tortoise (Astrochelys radiata) in the wild in Madagascar. This species is classified as endangered. Photo: Anders G.J. Rodin, Chelonian Research Foundation

How to determine the species that should be protected in the first place? To answer this question, scientists use a measure called phylogenetic diversity. It is a measure of biodiversity that takes into account not only the absolute number of species, but also the richness of their evolutionary history. Phylogenetic diversity is associated with genetic changes acquired by a species in the course of its evolution, and allows preference to be given to reptile species with the longest evolutionary history.

“Genes retain traits from the past, such as having teeth or behavior that is different from today. It’s a kind of genetic memory,” said Blair Hedges, director of the Temple University Biodiversity Center in Pennsylvania. “The measurement of phylogenetic diversity has made it possible to compile an evolutionary tree of reptiles. Thus, we found that approximately 16 billion cumulative years of evolution would be lost if all endangered species disappeared,” he emphasizes.

The researcher cites the example of the Galapagos marine iguana, an endangered species that has adapted very well to marine life. “Reptiles have evolved this unique way of life over the course of approximately 5 million years.” The loss of phylogenetic diversity will be greater in Southeast Asia, India, West Africa and the Caribbean.

Protected areas for everyone

Even if some reptiles need targeted protection measures, especially those living on islands, the creation of global protected areas is beneficial for all fauna and flora. “We found that most of the protected areas created for birds, mammals and amphibians probably helped to protect many endangered reptiles at the same time,” explained Bruce Young.

Unlike mammals or birds, which are considered friendlier in appearance, reptiles attract little attention and are more likely to go unnoticed by conservation efforts.

Researcher Bruce Young reports that this study is the result of more than 15 years of work due to funding difficulties because “reptiles are not as charismatic as furry or feathered vertebrates. »

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