A recent study has shown that frogs living in disturbed habitat where the rainforest is cleared actually have less risk of being infected by chytrid fungus than those in untouched rainforest. In other words, frogs are more likely to be decimated by Bd infections in their natural habitat. This means that even if pristine habitat is preserved in areas of concern such as Central & South America and Australia, amphibians may still be at risk of extinction from outbreaks of Bd.
One explanation for this conundrum is that, in deforested areas, it is possible that only the frogs most resistant to pathogens like the amphibian chytrid fungus survive and all of the more sensitive species (such as species from the Atelopus genus) are wiped out by the destruction of their habitat. The diversity of frog species may also have a role to play in disease transmission, since there are more species of frogs in untouched rainforest than in cleared areas. The greater biodiversity of amphibians in their natural habitat may lead to increased movement of the fungus from species to species. In cleared or deforested areas, populations of frogs are often fragmented so that outbreaks of disease may become localized in one area. Another explanation is that when the temperature of the environment increases due to loss of the trees (and the loss of shade), conditions become less favorable for the growth of Bd. Batrachochytrium dendrobatidis prefers cooler temperatures and is thus typically associated with higher elevation areas. Whatever the case may be, the complexity of natural ecosystems often makes comprehensive amphibian conservation difficult. While destroying pristine rainforest is obviously not a solution to preventing amphibian decline, unfortunately, preserving their natural habitat may not 100% guarantee the frogs’ safety either.