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Comprehensive Study of World’s Reptiles
More Than One in Five Reptile Species are Threatened with Extinction, But Many Likely Benefit From Efforts to Save Other Animals

Conservation efforts for other animals have likely helped protect many reptile species, according to a new study led by NatureServe, the International Union for Conservation of Nature (IUCN), and Conservation International. The study, published in the journal Nature, presents an analysis of the first comprehensive extinction risk assessment for reptiles on The IUCN Red List of Threatened Species™, which found that at least 21% of all reptile species globally are threatened with extinction. 

For the Nature study, a diverse research team, representing 24 countries across six continents, analyzed the conservation needs of 10,196 reptile species in comparison with mammals, birds, and amphibians. Reptiles in the study include turtles, crocodiles, lizards, snakes, and tuatara, the only living member of a lineage that evolved in the Triassic period approximately 200-250 million years ago.


A map shows the richness of threatened reptile species across the world.

Geographic distribution of threatened reptiles. Reptile species are considered threatened if ranked as Vulnerable, Endangered, or Critically Endangered by The IUCN Red List of Threatened Species™. Species richness refers to the number of different species that occur in an area. Warmer (redder) colors denote a larger number of threatened reptile species.
Cox, N. and Young, B. E., et al. Global reptile assessment shows commonality of tetrapod conservation needs. Nature (2022).


The research revealed that efforts to conserve threatened mammals, birds, and amphibians are more likely than expected to co-benefit many threatened reptiles. Although reptiles are well known to inhabit arid habitats such as deserts and scrubland, most reptile species occur in forested habitats, where they –and other vertebrate groups – suffer from threats such as logging and conversion of forest to agriculture. The study found that 30% of forest-dwelling reptiles are at risk of extinction, compared with 14% of reptiles in arid habitats.

I was surprised by the degree to which mammals, birds and amphibians, collectively, can serve as surrogates to reptiles,” said Dr. Bruce Young, co-leader of the study and Chief Zoologist and Senior Conservation Scientist at NatureServe. “This is good news because the extensive efforts to protect better known animals have also likely contributed to protecting many reptiles. Habitat protection is essential to buffer reptiles, as well as other vertebrates, from threats such as agricultural activities and urban development.” 

The study also highlighted what we stand to lose if we fail to protect reptiles. If each of the 1,829 threatened reptiles became extinct, we would lose a combined 15.6 billion years of evolutionary history—including countless adaptations for living in diverse environments. 

The results of the Global Reptile Assessment signal the need to ramp up global efforts to conserve them,” said Neil Cox, co-leader of the study and Manager of the IUCN-Conservation International Biodiversity Assessment Unit. “Because reptiles are so diverse, they face a wide range of threats across a variety of habitats. A multifaceted action plan is necessary to protect these species, with all the evolutionary history they represent.

The authors note that urgent, targeted conservation measures are still necessary to protect some of the most threatened reptile species, especially island endemic lizards threatened by introduced predators and those that are more directly impacted by humans.  For example, hunting, rather than habitat modification, is the main threat to turtles and crocodiles, half of which are at risk of extinction.


A box turtle, skink, and king cobra.

Reptiles at risk of extinction. From left to right: Zhou’s Box Turtle (Cuora zhoui), IUCN Red List Status: Critically Endangered, photo by Christian Langner, Allwetter Zoo; Otago Skink (Oligosoma otagense), IUCN Red List Status: Endangered, photo by Bernard Spragg; King Cobra (Ophiophagus hannah), IUCN Red List Status: Vulnerable, photo by Mark Auliya.


The findings of the Global Reptile Assessment serve as a baseline that can be used to measure changes in extinction risk and track species recovery progress over time. Results will also be valuable to help guide allocation of conservation resources through identification of Key Biodiversity Areas and other places where active management could prevent extinctions.

Reptiles are not often used to inspire conservation action, but they are fascinating creatures and serve indispensable roles in ecosystems across the planet. We all benefit from their role in controlling pest species and serving as prey to birds and other animals,” stated Dr. Sean T. O’Brien, President and CEO of NatureServe. “The analysis of the first Global Reptile Assessment enable us to pinpoint where reptiles need the most help and serve as a major step to countering the global extinction crisis.

Over 900 scientists were recruited to contribute to the IUCN Red List assessments, the findings of which helped inform this analysis.

Editor's Notes

The global biodiversity crisis will take center stage this year as the UN’s Convention on Biological Diversity convenes its Conference of the Parties – COP15 – in Kunming, China with the goal of finalizing the post-2020 Global Biodiversity Framework. This framework will have the potential to do for species what the Paris Climate Agreement has done for global warming: set the course of biodiversity conservation for the next decade.

Supporting Quotes

"The potential loss of one fifth of all reptile species reminds us how much of Earth's biodiversity is disappearing, a crisis that is threatening all species, including humans," said Maureen Kearney, a program director at the U.S National Science Foundation, which funded much of the study research conducted in Latin America and the Caribbean. "It is critical we understand extinction risk data for all species if society is to develop strategic, effective conservation efforts, and this study fills a gap in that understanding. These researchers and the knowledge they’ve provided highlight how a global understanding of biodiversity can only be gained by large, international teams of field experts conducting difficult, time-consuming, and often underappreciated 'boots-on-the-ground' work.

"These study results show that reptile conservation research no longer needs to be overshadowed by that of amphibians, birds and mammals. It is concerning though that more than a fifth of all known reptile species are threatened,” said Mark Auliya, Zoological Research Museum Alexander Koenig, Leibniz Institute for the Analysis of Biodiversity Change.Findings from this work must now be channeled into concrete research activities to classify the degree of endangerment of certain species and thereof derive targeted conservation measures. However, for the sustainable conservation of reptile diversity and their ancestral ecosystems, an interdisciplinary approach involving responsible actors is an indispensable prerequisite to halt the increase in threatened species.

It’s great to see this exceptional work of more than 900 experts come to fruition – assessments such as this form the basis for conservation planning and action,” said Monika Böhm, Institute of Zoology, Zoological Society of London.While we have likely already provided some conservation benefits to reptiles through protecting other species of mammals, birds and amphibians, we now need to take what we learned from this Global Reptile Assessment to instigate targeted conservation action on the ground, improve the conservation status of these magnificent creatures and reverse the red.

Australia is a global reptile hotspot, being home to around 10% of the world’s species. The vast majority of these species are endemic to Australia,” said Professor David G. Chapple, School of Biological Sciences, Monash University.The Global Reptile Assessment revealed that the plight of Australia’s reptiles has deteriorated over the past 25 years, with a doubling of the number of threatened species, and the first recorded extinction of an Australian squamate reptile (Christmas Island forest skink, Emoia nativitatis), and two species becoming Extinct in the Wild (blue-tailed skink, Cryptoblepharus egeriae, and Lister’s gecko, Lepidodactylus listeri).

The recent IPBES Global Assessment Report on Biodiversity and Ecosystem Services bases one of its conclusions on data for 1,500 reptile species. Our work provides a more complete picture of the status of an Essential Biodiversity Variable, the distribution and status of species, by providing an in-depth analysis, updated geographies, and extinction risk for more than 10,000 reptile species,” said Miguel Fernandez, Post-doctoral Researcher at the German Centre for Integrative Biodiversity Research (iDiv) and Affiliate Faculty at the Department of Environmental Science and Policy at George Mason University.On a personal level this publication helps me to remember an obvious truth, that our responsibility is to leave to future generations a planet equal or better than the one we are living on with respect to other living species.

Besides revealing general patterns of extinction risk, this study has identified hot spots of threatened reptile species, such as in the Caribbean islands, where we need to focus our efforts,” said Blair Hedges, Carnell Professor and Director of the Center for Biodiversity at Temple University.Extinctions are already occurring from deforestation alone, and climate change is now accelerating the process, especially in countries like Haiti where nearly all primary forest has been destroyed. We are quickly running out of time.

From turtles that breathe through their genitals to chameleons the size of a chickpea, reptiles are an eclectic bunch,” said Mike Hoffmann, Head of Wildlife Recovery at the Zoological Society of London.Many reptiles, like the Tuatara or Pig-nosed Turtle, are like living fossils, whose loss would spell the end of not just species that play unique ecosystem roles, but also many billions of years of evolutionary history. Their future survival depends on us putting nature at the heart of all we do.

Reptiles from Christmas Island, an Australian island south of Sumatra, are highlighted in the study as they are examples of reptiles severely impacted by invasive predators,” said Nicola J. Mitchell, School of Biological Sciences, The University of Western Australia.In this instance, an invasive Wolf Snake from Asia drove a recent collapse of the reptile community. Fortunately, captive breeding was initiated in time to save two of the species from extinction, and captive-bred blue-tailed skinks have now been introduced to snake-free islands in the Cocos-Keeling archipelago, more than 1000 km from Christmas Island. We may need many more actions such as this to secure our astounding reptile diversity, especially as many reptile habitats will be lost due to climate change.

In respect to conservation, the chelonians are very important,” said Philipp Wagner, Curator at Allwetterzoo, Germany and responsible for the International Centre for the Conservation of Turtles.More than 50% of the species are threatened and many of the Asian species are assessed as critically endangered. Cuora zhoui for example is only known from captivity with less than 200 individuals.

This comprehensive global assessment increases our understanding of the conservation status of reptile species assessed to date. It highlights the importance of identifying Key Biodiversity Areas and providing protection for microendemics that occur outside of existing protected areas and the fragile ecosystem they inhabit before they are lost due to development,” said Hana Saif Al Suwaidi, Chairperson of Environment and Protected Areas Authority, Sharjah.The diverse reptile species of arid regions, which are perfectly adapted to harsh environmental conditions and are often poorly represented in conservation actions, were not overlooked in this study.

The outcome of this study provides strong motivation for taking conservation forward in Africa,” said Krystal Tolley of the South African National Biodiversity Institute in Cape Town, South Africa.Contrary to prior assumptions, our results showed there are elevated threat levels for forest reptiles. Given that the African continent is currently undergoing substantial habitat loss, especially for indigenous forests, we can now link forest loss to the high threat level of reptiles. Ultimately, conservation starts with recognition of what the impacts are, and from there, we can design solutions.


About NatureServe

For nearly 50 years, NatureServe has been the authoritative source for biodiversity data and the central coordinating organization for a network of over 60 member programs throughout North America.  Together, NatureServe and the Network of member programs are dedicated to developing, collecting, and analyzing biodiversity information to support informed decisions about managing, protecting, restoring, and conserving natural resources. NatureServe and the Network develop and manage data for over 100,000 species and ecosystems, answering fundamental questions about what exists, where it is found, and how it is doing.
About IUCN

IUCN is a membership Union uniquely composed of both government and civil society organisations. It provides public, private and non-governmental organizations with the knowledge and tools that enable human progress, economic development and nature conservation to take place together. Created in 1948, IUCN is now the world’s largest and most diverse environmental network, harnessing the knowledge, resources and reach of more than 1,400 member organisations and some 18,000 experts. It is a leading provider of conservation data, assessments and analysis. Its broad membership enables IUCN to fill the role of incubator and trusted repository of best practices, tools and international standards. Combining the latest science with the traditional knowledge of local communities, the IUCN works to reverse habitat loss, restore ecosystems, and improve people’s well-being.
Conservation International About Conservation International
Conservation International protects nature for the benefit of humanity. Through science, policy, fieldwork and finance, we spotlight and secure the most important places in nature for the climate, for biodiversity and for people. With offices in 30 countries and projects in more than 100 countries, Conservation International partners with governments, companies, civil society, Indigenous peoples and local communities to help people and nature thrive together. Go to for more, and follow our work on Conservation News, Facebook, Twitter, TikTok, Instagram and YouTube.