Christine Dell’Amore | National Geographic News
Silent and secretive creatures, salamanders are just as quietly falling off the map in tropical forests throughout Central America, a new study says.
Two common species surveyed in the 1970s in cloud forests of southern Mexico and Guatemala are extinct, and several others have plummeted in number, researchers say.
The tiny amphibians seem to be on the same downward spiral as their frog cousins, which have been mysteriously declining for years.
Scientists have identified chytrid, a fast-killing fungus that may spread in waves, as responsible for wiping out frogs around the world. Others have said that climate change is shifting temperatures and humidity, factors intricately tied to amphibian survival.
But among the Central American salamanders, “we have no evidence that either chytrid or climate change is responsible for the declines,” said study author David Wake, an biologist at the University of California, Berkeley.
“Completely Gone”
In the 1970s, Wake spent several years researching lungless salamanders in the San Marcos region of western Guatemala, one of the most diverse and well-studied salamander communities in the American tropics.
Between 2005 and 2007, he and colleagues returned to that region and previous study sites in Mexico to survey salamanders and compare their results to the historical data.
Their data-collecting strategy remained the same: Spot as many salamanders as possible in a standard amount of time.