Environmental stress increasing infectious disease in amphibians

Environmental Research Web: Climate change, habitat destruction, pollution and invasive species are all involved in the global crisis of amphibian declines and extinctions, researchers suggest in a new analysis, but increasingly these forces are causing actual mortality in the form of infectious disease.

Amphibians are now, and always have been hosts for a wide range of infectious organisms, including viruses, bacteria and fungi, scientists said in a review published in Philosophical Transactions of the Royal Society B.

But in recent decades, disease seems to have taken a more prominent role in causing mortality. Because of multiple stresses, many induced by humans, amphibians now succumb to diseases they may historically have been better able to resist or tolerate.

"There's more and more evidence of the role of disease in the biodiversity crisis, in both amphibians and other types of animals," said Andrew Blaustein, a distinguished professor of zoology at Oregon State University and author of the recent analysis.

"It's normal for animals to deal with infectious organisms, often many of them simultaneously," he said. "But in the face of pollution, a reduced immune response, climate change, evolving pathogens and many other stresses in such a short period of time, many species now simply can't survive."...

Frog's eye close up, shot by Ren West, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

'Frog song' may help understand climate change

Jayashree Nandi in the Times of India: If not kissing the frog, at least appreciating their 'croak' may lead to some headway in to climate research . For the first time frog song is being monitored using automated sound recorders by Indian scientists to track the impact of climate change on amphibians in the forests of southern Western Ghats. The methodology for tracking their call has recently been standardized by researchers.

Principal investigators of the study were struck with the idea when three of them were 100 feet above the ground on a rainy day, sitting on a tree shelter for canopy research at Kalakad Mundanthurai Tiger Reserve. They heard frog song and decided to investigate how it could relate to climate.

Since frogs and toads respond to changes in atmospheric moisture and temperature, the team decided on analysing the sound recordings of frog song and corelate it with readings from climate data loggers.

"Amphibians have long been considered to be the barometers of the climate any subtle variations in the atmospheric conditions like moisture availability and temperature is likely to have profound impacts on them' said Seshadri.KS, who is heading the project and is part of the team that won the Conservation Leadership Programme-Save Our Species with senior fellow at Ashoka Trust for Research and Ecology, Ganesh T...

The fungoid frog (Hylarana malabarica) is a colourful fellow found on the forest floor and lower vegetation in the Western Ghats in south-western India, shot by Ajith U, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 2.0 Generic license