Climate change implicated in amphibian and lizard declines

Abstract

Amphibians are in trouble around the world. Awareness of the problem slowly grew in the 1980s. Among the earliest reported incidents were the disappearances of Golden Toads and Harlequin Frogs in the Monteverde Cloud Forest Reserve in Costa Rica in 1986–1987 (1), but soon there were many others. The Declining Amphibian Population Task Force, organized in 1991, served as a conduit for information arriving from many parts of the world and also was an important source of seed grant funding to encourage field research on amphibians, especially in understudied areas. Throughout the 1990s, reports continued to accumulate. Many amphibian biologists, especially those in apparently unaffected areas, were dubious and suspected that population fluctuations were being mistaken for monotonic declines. When long-term field studies (2) confirmed the early reports from Monteverde and reports of declines continued to accumulate, doubts essentially vanished. However, in many parts of the world, amphibians seemed to be doing well, and in discussing amphibian declines, it became standard to state, almost as a disclaimer, that the main reason for the decline was habitat destruction and conversion. But as data accumulated, it became apparent that the earliest reports of declines and disappearances from relatively undisturbed tropical upland habitats were not exceptional but were becoming typical. Tropical lowland environments seemed to be spared, but that perception is altered by an alarming new report by Whitfield et al. (3) in this issue of PNAS.