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One study finds that rare species believed to be extinct cling to survival




Up to just 5.5 centimeters (2.2 inches) long, the critically endangered Chapman pygmy chameleon (Rhampholeon chapmanorum) is native to the low-lying rainforest of the Malawi hills in southern Malawi, a southern country. -East Africa, according to a study published Monday in Oryx – The International Journal of Conservation.
First described by herpetologist and author Colin Tilbury in 1992, Chapman’s Pygmy Chameleon is one of the rarest chameleons in the world.
“They’re mostly brown, but they can change to pretty blue and green with little dots everywhere and it’s probably a way to communicate with each other,” said study lead author Krystal Tolley, professor and leader of research at Leslie Hill. Molecular ecology laboratory of the National Institute of Biodiversity of South Africa, a a statement. “Other species of chameleons may be hysterical, whistling and biting, but pygmy chameleons are soft and just beautiful.”
The risk of extinction of chameleons is much higher than the average of 15% for the order of reptiles to which they belong, with 34% of chameleon species classified as threatened and 18% almost threatened, wrote the authors. Most endangered species are forestry specialists, which means they can only live in one particular type of environment.

Survival through agricultural acquisitions

When Tilbury first described Pygmy chameleons in 1992, previous researchers noticed signs of substantial deforestation in Malawi Hills, wrote the authors of the current study. According to the study, to protect the species from further damage, 37 pygmy chameleons based in Malawi Hills were released into a forest area about 95 kilometers north in Mikundi, Malawi, in 1998. When Tilbury assessed the site of ‘release in 2001 and 2012, the chameleons were still there.
Because pygmy chameleons are intolerant of transformed areas and Tolley did not discover any pygmy chameleons during related evaluation work in 2014, it was thought that they had possibly become extinct. His work led the International Union for Conservation of Nature to list chameleons as critically endangered. Red list of endangered species. Using historical (1984-1985) and recent (2019) satellite images from Malawi Hills ’Google Earth and another geographic information system, the authors of the current study estimated that approximately 80% of Malawi’s forest Hills had been destroyed between 1984 and 2019.

At night, on the trails of three accessible forest spots, in 2016, the authors walked with torches to find and record chameleons.

“The first thing we found was in the transition zone on the edge of the forest, where there are some trees, but mostly corn and cassava plants,” Tolley said. “When we found it, we had goosebumps and started jumping. We didn’t know if we would get any more out of it, but once we got into the woods there was plenty of it, although I don’t know how long it will last.”

Researchers found seven adult chameleons along a trail just inside Malawi Hills ’first forest area; 10 chameleons inside a site more than 6 kilometers (4 miles) southwest of the first; and 21 adult chameleons plus 11 pups and pups inside the patch at Mikundi, the site of the 1998 release.

Pygmy chameleons still face threats

After ripping 2-millimeter-long (0.1-inch-long) tail clips from some adult chameleons, the authors performed genetic analysis. The authors found that the genetic diversity of chameleons was normal compared to that of other chameleons and small-bodied reptile species. But there were significant differences in genetic structure between populations from different areas, suggesting that humans fragmenting forest patches had altered reproductive capacity among chameleons from neighboring patches and therefore their gene flow, a impact that increases the risk of extinction due to fewer options for peers. , wrote the authors.

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However, the authors may have overestimated the amount of genetic diversity among populations by not considering how some DNA is inherited, said Eric Routman, professor emeritus of biology at San Francisco State University. participated in the study.

“And even if they had a lot of loci and good genetic estimates, they don’t have any estimate of these genetic parameters before habitat fragmentation, so they can’t attribute any genetic effect to deforestation,” Routman added for e-mail. “If I had been reviewing this article, I would have recommended major revisions of the manuscript. Essentially, the genetic part of his study is inconclusive.”

The authors think that the effects of deforestation on genetic diversity could take time to emerge. But to prevent chameleon species from reaching a point of no return, the loss of the rainforest requires immediate attention, Tolley said.

“Urgent conservation action is needed, including halting forest destruction and habitat recovery to promote connectivity. The effectiveness of the forest reserve is questionable, as most of the destruction has been within of its limits, “the authors wrote. “While expanding the reserve to include all forest areas would be a first step, measures are needed to prevent the destruction of the remaining areas.”

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These efforts would be important also for any other species that possibly lives among these chameleons, the authors wrote. And there could be more pygmy chameleons on the spots that they weren’t able to explore, they said.

For the little creatures Polley described as soft and beautiful, “both planning and recommended actions require strong leadership, staff, stakeholder involvement, including government departments, and sufficient funding to ensure success.” , the authors added.