Krystal Tolley wasn't sure if the tiny Chapman's pygmy chameleon — considered an extremely rare and critically endangered species of reptile — was already extinct when she and two colleagues went searching for it in East Africa in 2016.
No one had reported a sighting of the chameleon since the 1990s when it was first discovered. Moreover, the rainforests they inhabited had lost a significant amount of coverage over the decades.
The remarkably tiny lizard reaches a maximum length of only 6.2 centimeters and is one of several species in the genus Rhampholeon, commonly known as pygmy chameleons, native to East Africa. But at the edge of a patch of forest still left intact in Malawi, they spotted their first chameleon, confirming that the vanishing species was still somehow hanging on.
In other patches of forest, they found even more of the chameleons.
"It's a massive relief," said Tolley, a herpetologist at the South African National Biodiversity Institute and lead author of a new study in Oryx that reported the pygmy chameleon sightings.
Chameleons, a type of reptile mostly found in sub-Saharan Africa, have the unique ability to change the color of their skin to blend in with their surroundings, communicate or regulate their body temperatures. Over a third of the world's chameleon species are at risk of extinction, according to the International Union for Conservation of Nature (IUCN), many driven by the loss of their habitats. The burning and chopping of forests for agriculture and logging has had an especially detrimental impact on their populations, according to Tolley.
In 2013, Tolley began to help assess the extinction risk status of the over 200 identified chameleon species to add to IUCN's Red List of Threatened Species. While looking at satellite images of the rainforest where the pygmy chameleon was known to live, Tolley realized that the rainforest coverage had shrunk by an estimated 80% since 1984. Based on how little of the forest appeared to remain, Tolley and her colleagues feared that the species no longer existed.
"We all knew that we would need to go and check, when we saw the size of the forest patches," Tolley told VOA.
In the rainforests in southern Malawi, the team members had to carefully make their way through the forest at night to search for the chameleons by torchlight.
That was because by day, the small pygmy chameleons were tricky to spot. They hid on the forest floor by adopting a dusty brown appearance to blend in among the dried leaves. But by night, they crawled up to sleep on low-lying bushes to keep away from the snakes and other predators slinking below. At night, the chameleons were more visible against the vegetation. When researchers' light hit the first Chapman's pygmy chameleon, they spotted it immediately.
The researchers also collected samples from some of the chameleon's tails to analyze their DNA. The genetic diversity of the populations, which is important for a species to adapt to changing environments, seemed sufficient compared to other chameleon species.
However, researchers also found differences in the DNA between populations discovered in separate forest patches. These results suggested that the fragmented forested areas may have split up what was once a single larger population into smaller, more genetically distinct and isolated groups. Although the authors note that they can't compare the change over time without any past DNA samples, these results still imply a growing risk of extinction in the future.
The researchers have gained valuable information about the Chapman's pygmy chameleon and its survival, but the declining state of the habitats they're connected to continues to threaten the chameleons, other wildlife species and the landscape.
"The paper found what is indicative of what's happening throughout the world and forested parts of eastern Africa … of global habitat transformation, conversion of forests lands for a variety of human uses, that can have impacts on chameleons and any other forest-dependent species," said James Vonesh, who studies conservation biology at Virginia Commonwealth University and was not involved in the study. "Sadly, it's not a surprise."
Extending the borders of the protective reserves that cover some of the Malawian forests or strengthening enforcement could be a first step toward protecting the chameleons, according to the authors. To restore the wildlife and the habitats that are now gone will be another challenge, one which may require the involvement of local communities, government departments, international conservation organizations and more.
"There's often not an easy answer to these kinds of situations," added Vonesh.
Despite the excitement surrounding the discovery, Tolley continues to worry about the potential destruction of the forests.
"This is a global problem, and it doesn't benefit our own human society and our own wellbeing to remove all the natural habitats," Tolley said.