21% of reptile species are threatened

More than 21% of reptile species are threatened with extinction according to an overall analysis of 10,000 species.

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

To assess the condition of reptiles (vulnerable, endangered, critically endangered), an international team of researchers relied on the criteria of the International Union for Conservation of Nature’s (IUCN) Red List. ). They found that 1,829 of the 10,196 species of reptiles, or 21.1%, are threatened with extinction. Crocodiles and turtles are among the most endangered animals.

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

“Much of the endangered reptiles occupy the regions of Southeast Asia, West Africa, northern Madagascar and the Andes and the Caribbean,” said Bruce Young, co-director of the study and chief zoologist. of the environmental organization NatureServe during a press conference. Contrary to what researchers believe, reptiles that live in forests are more at risk than those that live in arid environments, such as the desert. Forests, threatened by the timber industry and conversion to agricultural land, are becoming a less favorable environment for reptiles.

Millions of years of evolution

The Madagascar turtle (Astrochelys radiata) photographed in the wild in Madagascar. This species is classified as critically endangered. Photo: Anders GJ Rhodin, Chelonian Research Foundation

How to determine which species should be protected as a matter of priority? 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 deals with the genetic changes that a species has acquired during its evolution and allows priority to be given to reptile species with the longest evolutionary history.

“Genes retain the signature of past traits, such as the presence of teeth or behavior different from the current one. It’s a kind of genetic memory, “said Blair Hedges, director of the Center for Biodiversity at Temple University in Pennsylvania.” The measurement of phylogenetic diversity has allowed us to draw the evolutionary tree of reptiles. Cumulative 16 billion years of evolution would be lost if all endangered species disappeared, ”he said.

The researcher cites the Galapagos marine iguana as an example, an endangered species that has adapted very well to marine life. “The reptile developed this unique way of life over a period of about 5 million years.” The loss of phylogenetic diversity would be greatest in Southeast Asia, India, West Africa, and the Caribbean.

Protected areas for everyone

Although some reptiles need specific protection measures, especially those living on the islands, the establishment of global protection zones is beneficial for all fauna and flora. “We found that most of the protected areas created for birds, mammals and amphibians probably helped protect many endangered reptiles at once,” Bruce Young said.

Unlike mammals or birds that are considered more friendly in appearance, reptiles attract little attention and are often overlooked by conservation efforts.

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

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