The Monteverde golden toad went extinct in 1989. Photo: Wikipedia.
This probably won't be the last word on the demise of the Monteverde golden toad, but a new paper in Proceedings of the National Academy of Sciences says that normal El Niño conditions, not climate change, lead to the spread of the deadly chytrid fungus and caused the iconic Costa Rican species to go extinct.Science Codex sums up the report, by scientists from Columbia University's Lamont-Doherty Earth Observatory:
The golden toad vanished after an exceptionally dry season following the 1986-1987 El Niño, probably not long after the chytrid fungus was introduced. Scientists speculate that dry conditions caused the toads to congregate in a small number of puddles to reproduce, prompting the disease to spread rapidly. Some have linked the dry spell to global warming, arguing that warmer temperatures allowed the chytrid pathogen to flourish and weakened the toad's defenses. The new study finds that Monteverde was the driest it's been in a hundred years following the 1986-1987 El Niño, but that those dry conditions were still within the range of normal climate variability. The study does not address amphibian declines elsewhere, nor do the authors suggest that global warming is not a serious threat to biodiversity.
As for that 'won't be the last word' part: The lead author of the study in Nature back in 2006, which first made the climate-golden toad extinction connection, disagrees with this study's findings. J. Alan Pounds claims the the authors of the PNAS paper missed a long-term drying trend "because they were unable to analyze moisture variations day to day or week to week."
Pound added, "Anyone paying close attention to living systems in the wild is aware that our planet is in serious trouble. It's just a metter of time before this becomes painfully obvious to everyone."
via: Science Codex
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