The reptiles of the world have been added to the 'Atlas of Life'

Where do all the species live? If we want to preserve wildlife as best we can, this is a crucial question. So, for the last decade, researchers have been working on mapping out the distributions of the world's land-living vertebrates. Birds, mammals and amphibians have been mostly done, and now the last puzzle piece has been added, with reptiles finally joining their cousins on the "atlas of life".

The new study pulls together location data for an astounding 10,064 species, for a total of 99% of known living reptile species. Image: Pixabay

Understanding how species are spaced out is critical when deciding what habitats to protect and where to allocate money and resources for conservation. This global view of biodiversity has helped organisations around the world to safeguard species, but the distribution of reptiles hasn't been very well understood – and it's been a challenge to figure out. This means most conservation issues are not considering reptilian species, even though they make up an entire third of terrestrial vertebrate diversity.

"Mapping the distributions of all reptiles was considered too difficult to tackle," said Shai Meiri of Tel Aviv University, who has been a leader on the project since its inception. "But thanks to a team of experts on the lizards and snakes of some of the most poorly known regions of the world we managed to achieve this."

The new study, put together by 39 scientists from around the world comprising the Global Assessment of Reptile Distributions groups (GARD), pulls together location data for an astounding 10,064 species of lizards, snakes, turtles, crocodilians and even the bizarre tuataras, for a total of 99% of known living reptile species. These scaly critters join the roughly 10,000 birds, 5,000 mammals and 6,000 amphibians already in the database.

This map shows species richness around the world, now considering nearly all terrestrial vertebrates: birds, mammals, amphibians and reptiles! Image: University of Oxford

So, how does the new reptile-loaded map change our perspective on conservation? In some ways, not very much; snakes, for example, seem to fall mainly in the same tropical regions that are already being targeted for protection for other animals, such as southeastern Asia and North America.

But other reptiles break from the trends seen in most vertebrates, such as turtles and particularly lizards. These animals are not being protected by most conservation programmes currently in place.

"Lizards especially tend to have weird distributions and often like hot and dry places, so many of the newly identified conservation priority areas are in drylands and deserts," said Uri Roll of the Ben Gurion University of the Negev. "These don't tend to be priorities for birds or mammals, so we couldn't have guessed them in advance."

The study pinpointed several new areas in danger of falling to ecological fragility, such as northern Africa, central Asia, central Australia and the southern Andes, among others.

This map highlights some of the regions pinpointed as higher priority for conservation by the study – now that reptiles are being considered as well. Image: University of Oxford.

The study also found that existing protected areas don't cover reptiles very well. Whereas approximately 6% of bird and mammal species live in ranges contained with protected regions, just over 3% of reptiles (and amphibians, for that matter) do. Lizards and turtles especially have a tendency to live outside of currently safeguarded areas.

Lizards needing protection in arid environments is a mixed blessing for conservationists. On the one hand, dry regions tend not to be centres of agriculture, so conservation efforts are less likely to interfere with land use.

"But deserts and drylands are also home to lots of other modern activities, such as major irrigation projects, huge new solar power developments, and sometimes widespread land degradation, war and conflict,” said Richard Greyner of Oxford University. "This makes them very challenging environments for conservationists to work."

The International Union for the Conservation of Nature (IUCN) is in the process of using this new information to classify the statuses of species, considering how their regional preferences affect their level of endangerment. Once that is complete, the new resource will be open for anyone to access and use at no cost.

"Thanks to tools like our atlas, scientists can for the first time look at the terrestrial Earth in its entirety, and make informed decisions about how to use conservation funding," said Greyner. "[N]ow conservation has the data and tools required to bring planning up to the same level as the businesses and governments who might have an eye on land for other uses."