At only 5.5 centimeters (2.1 inches) long, the critically endangered Chapman’s pygmy chameleon (Rhampholeon chapmanorum) lives in the low-elevated rainforest of the Malawi Hills. It’s one of the world’s rarest chameleons and one of the most threatened, losing its territory because of agricultural expansion.
The rare chameleon was first described in 1992 by herpetologist Colin Tilbury and was feared to be extinct. But a survey done by researchers from the South African Biodiversity Institute in 2016, whose results are now being published for the first time, has found populations of the small reptiles living in remaining patches of the forest.
“They are mostly brown but they can change to quite beautiful blues and greens with little dots all over them and that’s probably a way of communicating with each other,” the study’s lead author Krystal Tolley said in a statement. “Other chameleon species can be hysterical, hissing and biting, but pygmy chameleons are gentle and just beautiful.”
Bad news for wildlife
Using historical (1984-1985) and recent (2019) Google Earth satellite imagery of the Malawi Hills and another geographical information system, the researchers estimated about 80% of the Malawi Hills forest had been destroyed from 1984 to 2019. This significantly altered the populations of the Chapman’s pygmy chameleon (along with other animals inhabiting the same area).
The team also visited the forest in 2016 and found that while the species was severely endangered, it wasn’t extinct yet. They saw seven adult chameleons along a footpath inside the first forest path, 10 inside a site six kilometers southwest of the first, and 21 adults inside a forest patch near Mikundi – where 37 chameleons had been released in 1998 to try to safeguard the species.
“The first one we found was in the transition zone on the forest edge, where there are some trees but mostly maize and cassava plants,” Tolley said in a statement. “When we found it we got goosebumps and just started jumping around. We didn’t know if we would get any more, but once we got into the forest there were plenty, although I don’t know how long that will last.”
Following their discovery, the authors went to the lab and carried out a genetic analysis, finding that the chameleons’ genetic diversity was normal in comparison to that of other chameleons. But there were many differences in genetic structure between populations in different areas. This suggests the fragmentation of the forest disrupted the chameleons’ breeding ability.
However, Eric Routman, a professor emeritus of biology at San Francisco State University, who wasn’t involved in the study, told CNN that the researchers might have overestimated the amount of genetic diversity between populations by not accounting for the way that some DNA is inherited. “The genetic part of their study is inconclusive,” he added.
Chameleons live mainly in Africa and the nearby island of Madagascar, and most species inhabit rainforests. As rainforests are fragmented by savanna, the chameleons have lived isolated from each other for millions of years. This has caused populations to evolve into distinct species that are highly adapted to forest life.
If the forest disappears, they are essentially doomed. And that’s what’s happening to many species, with growing deforestation rates in many countries in Africa. Nearly 40% of 218 chameleon species are threatened with extinction, with another 19% considered near-threatened. That’s why researchers are calling for comprehensive measures to protect them.
“Urgent conservation action is needed, including halting of forest destruction and recovery of habitat to promote connectivity,” Tolley and her team wrote in their study. “Although part of the Malawi Hills falls within a Key Biodiversity Area (Matandwe Forest Reserve) most of the forest falls outside the reserve boundary, and the effectiveness of the forest reserve is questionable.”
The study was published in the journal Oryx.