Global warming may cause extinction of 20 percent of all lizard species by 2080 — ‘Watching these species disappear before our eyes’

ScienceDaily (May 13, 2010) — For many lizards, global climate change is a matter of life and death. After decades of surveying Sceloporus lizard populations in Mexico, an international research team has found that rising temperatures have driven 12 percent of the country’s lizard populations to extinction. An extinction model based on this discovery also forecasts a grim future for these ecologically important critters, predicting that a full 20 percent of all lizard species could be extinct by the year 2080. The detailed surveys of lizard populations in Mexico, collected from 200 different sites, indicate that the temperatures in those regions have changed too rapidly for the lizards to keep pace. It seems that all types of lizards are far more susceptible to climate-warming extinction than previously thought because many species are already living right at the edge of their thermal limits, especially at low elevation and low latitude range limits. … Barry Sinervo from the Department of Ecology and Evolutionary Biology at the University of California in Santa Cruz, along with colleagues from across the globe, reached these conclusions after comparing their field studies of the lizards in Mexico with extensive data from around the world. Their research will be published in the May 14 issue of Science, the peer-reviewed journal published by AAAS, the nonprofit science society. … “How quickly can Earth’s lizards adapt to the rising global temperatures? That’s the important question,” Sinervo said. “We are actually seeing lowland species moving upward in elevation, slowly driving upland species extinct, and if the upland species can’t evolve fast enough then they’re going to continue to go extinct.” … The detailed study notes specifically that lizards that bear live young are particularly at risk of extinction, compared to those that lay eggs. “Live-bearers experience almost twice the risk of egg-layers largely because live-bearers have evolved lower body temperatures that heighten extinction risk,” Sinervo said. “We are literally watching these species disappear before our eyes.” Sinervo began focusing his attention on lizard extinctions after he noticed an obvious trend during his field work in France. He identified an unsettling pattern of lizard extinctions with French researchers, Jean Clobert and Benoit Heulin, while they were surveying some of their well-documented populations. Disturbed by their findings, they contacted colleagues around the world — Jack Sites and Donald Miles in the United States, Fausto Méndez-de-la-Cruz in Mexico, and Carlos Frederico Duarte Rocha in Brazil — and a global collaboration ensued. … For the authors, who claim a deep appreciation for these lizards and the important role the reptiles play in the global food chain, these findings are both “devastating and heart-wrenching.” …

As global temperatures rise, world’s lizards are disappearing: 20 percent of all lizard species could be extinct by 2080; Erosion of Lizard Diversity by Climate Change and Altered Thermal Niches