Reuters: Many salamander species in Mexico and Guatemala have suffered dramatic population declines since the 1970s, driven to the brink probably by a warming climate and other factors, U.S. scientists said on Monday. The salamanders’ fate provides the latest evidence of striking losses among the world’s amphibians, a phenomenon some experts see as a harbinger of doom for many types of animals. Biologist David Wake of the University of California Berkeley and colleagues tracked about …