The precipitous loss of amphibians in recent years has been blamed on habitat loss, global warming, fungal infections, and pesticides. Globally, all of these factors probably combine for a multiple whammy. Now, research
published online April 20 in Proceedings of the National Academy of Sciences U.S.A. reveals a new combo: climate change is causing some species to lose their leaf-layer habitat - and the damage is killing reptiles, too.
Steven Whitfield of Florida International University and colleagues examined 35 years' worth of data from the La Selva Biological Station in Costa Rica. The team found that populations of frogs and common reptiles such as lizards plummeted 75% since 1970. Globally, human activities are closely linked with disappearing frogs and salamanders. One-third of all amphibian species are threatened with extinction, according to a recent estimate
, in large part because humans encroach on their habitats and introduce nonnative species. But even in areas without large human influences, such as the patch of protected old-growth rainforest that the researchers studied, many species are disappearing.