All three creatures are very slow moving, he added, "but they have this ballistic tongue that shoots out at incredible speeds and wraps around prey." (Related: "Salamander Tongue Is World's Most Explosive Muscle" [March 9, 2007].)
The salamanders were among 5,300 plant, insect, and amphibian species recorded during three expeditions to the cloud forests of La Amistad, a 490,000-acre (198,000-hectare) United Nations World Heritage site that reaches elevations of more than 11,000 feet (3,350 meters) in places.
Two suspected new frog species and several unknown plants have also been identified as part of the project, which is funded by the U.K. government's Darwin Initiative to survey biodiversity in the region.
The La Amistad project also aims to shed light on the causes of a worldwide decline in tropical amphibians highlighted by recent studies.
Falling populations and extinctions have been linked to factors such as global warming, habitat loss, pollution, and a fungus found growing on dead and dying amphibians, Monro said.
"If this is a response to climate change, then we would expect amphibians to be shifting their range upwards as it gets warmer, and there is some evidence of that," he said.
"We have already documented a significant increase in elevation from one frog species."
Hunting the salamanders was painstaking work because of their small size and nocturnal habits, Monro added.
A survey area was marked out during the day, and the study team returned at night.
Likening the task to police investigating a crime scene, Monro said researchers had to pick through leaf litter and mossy tree trunks.
"They had to tease apart mosses and loose bark and look all around in very close detail," he said. "In a night, they will have probably done only a few trees and maybe a hundred meters of pathway."
Because of the obscurity of the region, four further expeditions are planned for 2008.
"Central America is quite a densely populated region, so it's amazing there are areas like this remaining which are relatively unexplored," Monro said.
The wildlife is protected largely thanks to the park's remoteness and inhospitable terrain, he added.
"It's very steep, very wet forest, and there are no roads, partly because it would be so difficult to put any in," Monro said.
Team member Eduardo Boza, a herpetologist at the University of Costa Rica, pointed out that Bolitoglossa is the most diverse salamander group in Costa Rica, with 21 described species. But much about the group remains mysterious.
Some species are known from less than five specimens, for instance, he said by email.
"They don't have lungs but breathe through their skin, and they don't live in water at any time," Boza said.
Instead of breeding aquatically, the amphibians lay eggs or give birth to live young on the forest floor, he said.
"Costa Rica is one of the best studied countries in the world at the level of herpetology, but despite this we are still describing new species," Boza added.
"Probably there will be more new species discovered in coming trips."
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