The snake Chironius monticola inhabits cloud forests at elevations of 3,300 to 10,500 feet (1,000 to 3,200 meters) in southern Peru's Manú National Park, on the western side of the Amazon Basin.
"Only a few snake species can live above 3,000 meters [9,800 feet]," said Rudolf von May, a postdoctoral fellow at the University of California, Berkeley who co-wrote a detailed survey of amphibians and reptiles in the park and its surrounding area, published in the journal Biota Neotropica.
Snakes are cold-blooded, he explained, so they need relatively warm temperatures to function. But "this snake is adapted to live at colder, higher elevations." Precisely how the snake does this is unknown, he added.
Von May and two colleagues—Alessandro Catenazzi of Southern Illinois University, Carbondale and Edgar Lehr of Illinois Wesleyan University in Bloomington—cataloged 155 amphibian and 132 reptile species, with support from the National Geographic Society, the National Science Foundation, the Rufford Small Grants Foundation, and the Amazon Conservation Association.
As a result of their findings, said von May, "Manú now stands as the park or protected area with the highest number of species of amphibians and reptiles on the planet."
Before their study, Yasuní National Park in Ecuador was first, with 150 amphibian and 121 reptile species, according to a study published in 2010 in PLOS ONE. Both Manú and Yasuní protect large areas of lowland rain forest, but Manú also spans high-elevation cloud forests and Andean grasslands.
Although Manú National Park represents only 0.01 percent of the planet's land area, it houses 2.2 percent of all amphibians and 1.5 percent of all reptiles known throughout the world, the scientists noted. The amphibians in the park include frogs, toads, salamanders, and caecilians. Reptiles include snakes, lizards, turtles, and caimans.
Manú also supports more than a thousand species of birds (about 10 percent of the world's total) and over 1,200 species of butterflies.
The region is home to several indigenous ethnic groups, including the Matsiguenka, Harakmbut, and Yine.
The scientists found Hyalinobatrachium bergeri, a type of glass frog, in the cloud forests of Manú National Park at elevations of 2,600 to 7,200 feet (800 to 2,200 meters). According to their paper, seven species of glass frog live in the park (more than 150 species are found across Central and South America).
Glass frogs are nocturnal and live along streams, especially in mountain forests, said von May. They're relatively small at 20 to 22 millimeters long, and lay their eggs on vegetation that hangs over streams. When the eggs hatch, the tadpoles drop into the water.
Glass frogs are said to be good indicators of stream health, von May added. "It is rare to see them in many areas now, but [you can find them] in Manú [because its] streams are clean."