In his article “Climate change may boost frog disease chytridiomycosis,” environmental correspondent Richard Black writes that more changeable temperatures, a consequence of global warming, may be helping to abet the threat that a lethal fungal disease poses to frogs.
Experimentation to get to the solution has been done with Cuban tree frogs (Osteopilus septentrionalis) infected with the parasitic fungus Batrachochytrium dendrobatidis that causes the disease. See excerpts with a link to the full article below:
Scientists found that when temperatures vary unpredictably, frogs succumb faster to chytridiomycosis, which is killing amphibians around the world. The animals’ immune systems appear to lose potency during unpredictable temperature shifts. The research is published in Nature Climate Change journal.
Chytridiomycosis, caused by the parasitic fungus Batrachochytrium dendrobatidis (Bd), was identified only in 1998. It affects frogs and their amphibian relatives – salamanders, and the worm-like caecilians – and has caused a number of species extinctions.
“I’m not convinced that the effect we’ve discovered could be considered responsible for declines or extinctions in the ways way that the spread of Bd can be considered responsible,” said Thomas Raffel, lead scientist on the new research. “It might be, however, that climate change has sped up the decline or extinction after the parasite arrived,” the Oakland University researcher told BBC News.
[. . .] Over the years, various teams of scientists have conducted a whole raft of experiments to find, for example, whether Bd is more active in warm or cold temperatures. Bd spores spread from the skin of amphibians. The new research looked at what happens in a more real-life situation – when chytrid fungus is actually on a vulnerable frog. And the key variable the scientists looked at was variability of temperature, rather than temperature itself.
Cuban tree frogs (Osteopilus septentrionalis) infected with Bd were kept under various conditions. [. . .] On its own, the fungus fared better in cooler conditions, and when the temperature changes were regular. But when it was already on the frogs, the pattern was reversed; the fungus grew faster under unpredictable temperature change. The explanation is that being a simpler organism, it is able to adapt faster than the frogs’ immune system. [. . .]
For full article, see http://www.bbc.co.uk/news/science-environment-19199197
Also see previous post, Frogs Rescued from Killer Fungus in Montserrat Reproduce in the UK