In November 2017, I had the opportunity to join a team of scientists led by herpetologist Miguel T. Rodrigues (University of São Paulo) in an extraordinary expedition to the Serra da Neblina, a very remote tepui (sandstone table-top mountain) on the Brazil-Venezuela border. The expedition involved the Brazilian Army, several Yanomami guides, and a team of BBC journalists. We collected around 2,500 samples of amphibians, reptiles, birds, small mammals, and plants between 80 and 2,995 m of altitude – among them, at least 10 frog and lizard species new to science!
As soon as we got to an elevation of around 2,000 m, we started looking for Anolis neblininus, the Neblina anole. This mysterious lizard was described based on six individuals collected on the Venezuelan portion of the mountain in the 80’s by a team of AMNH-Smithsonian scientists. To our surprise, it took us only a few hours to find one, two, several individuals – the first records of A. neblininus in Brazil!
The Neblina anole seems to be locally abundant, with more than 30 individuals found over a week. Because of their slow movements and cryptic coloration, these lizards are really hard to spot during the day. All but two individuals were found at night, sleeping on thin branches and leaves on the edge of forest patches, at a height of 1-4 meters above the ground. Although we set up 100 pitfall traps in the area to sample herps and small mammals, all of the anoles were found through active search.
To learn a bit about how much Neblina anoles move during the day, we experimented with spooling a few individuals. Based on how much thread they left along their way, it seems that A. neblininus does not move much in a day. Individuals go up and down short trees and bushes, but do not seem to walk on exposed ground. However, the spools that we had – leftovers from a study of larger Enyalius lizards – may have been too awkward for such small anoles to carry.
These montane lizards experience remarkably low temperatures. At night, when temperatures were as low as 6oC, the anoles were unresponsive for long periods after captured, apparently because they were too cold. On consecutive mornings, we followed individuals (spotted on the night before) to check at what time they would become active. To our surprise, the anoles started moving at different times in each day, between 6 and 9:30 am, in an apparent association with how cold it was. It is therefore possible that the onset of activity is given mostly by temperature, as opposed to when the sun comes out.
One interesting feature of A. neblininus is how variable their coloration is. Some individuals have gray bodies, others green or brown; some have yellow heads. They are also capable of changing their colors a bit. The dewlap is well developed in females, with dark spots on an orange or brown background. Male dewlaps are white, bluish, or yellowish. Neblina anoles have a very cool-looking dorsal crest, more developed in males.
Our recent studies of mainland anole lizard evolution and biogeography have found that A. neblininus is closely related to species from montane Atlantic Forest, Andes, and Andean foothills. This pattern may result from a history of cool habitats connecting South American mountains in the past, followed by habitat retraction and extinction in intervening areas. Our expedition to the Neblina revealed additional species that seem to be related with taxa from distant mountains. We are now examining their history based on genetic data to help shed light on the history of the mysterious tepui fauna.