Biologists from the University of California, Berkeley, have reported that salamander populations in parts of Central America have declined sharply in the past 40 years — and global warming could be the cause.
UC Berkeley researchers compared data of current salamander populations in western Guatemala and southern Mexico to data collected from the locations between 1969 and 1978. The team found that two of the most common species of salamanders in the areas 40 years ago are extinct, and several others have experienced large drops in number.
Amphibian populations have been declining worldwide, and experts have attributed the drops in other amphibian species — such as the well-documented plummeting of frog populations — to factors such as pesticides, predators and habitat destruction.
But according to David Wake, professor of integrative biology at UC Berkeley and the new study’s lead researcher, the salamanders in Guatemala lived on a controlled nature preserve, so neither outside predators nor human disturbance could have been responsible for their startling disappearance.
The nature preserve couldn’t guard the salamanders from the effects of global warming, however, and the climate conditions of salamanders’ habitat did change over the past 40 years. Salamanders are highly sensitive to climate and humidity, so even a slight increase in temperature could have caused them to seek higher elevations. Having thrived at their former altitudes for thousands of years, the salamanders were unable to adjust to these new habitats, researchers suspect.
Unlike other amphibians, salamanders are famously secretive creatures and often go unseen by all but keen, deliberate observers. Wake says salamanders’ effects in ecosystems do not go unnoticed, however: In forests, salamanders account for a large amount of biomass. Certain species even depend on salamanders for their own survival, such as the salamander-eating snake, which, according to Wake, is also showing signs of population decline.
See Science Daily's article for more information on Wake and his colleagues’ study, and check out A Wealth of Salamanders for more on these fascinating creatures and their unique presence in North America.
Photo by iStockphoto/Armin Hinterwirth