Learning what makes these frogs special could hold a key to managing the fungal scourge.
Amphibians include frogs, toads, salamanders and newts. And overall, notes Savage, “Amphibians are in trouble.” A recent study showed that populations have been shrinking for more than four in every 10 of the world’s amphibian species. Nearly one-third are threatened with extinction. And that could be bad for the environment. These animals are an important part of the food chain. They eat pesky insects, like flies and mosquitoes. Amphibians, in turn, are an important food source for many birds, reptiles and mammals.
Global loss of wetlands and other critical amphibian habitat may be causing some populations to shrink. A frog disease is causing major declines too. Its source is a single-celled fungus known as chytrid (KIH-trid). Fungal diseases are known as mycoses (My-KO-sees). So this one is called chytridiomycosis (Kih-TRID-ee-oh-my-KO-sis).
In the past few decades, this infection has been turning up all over the world. The fungus lives in wetlands and ponds. No one knows exactly where chytrid first came from. But once it infects their skin, many frogs now sicken and die.
The big question has been why some frogs have been spared. Savage now thinks she has an answer: their immune system.
Food chain: 食物链
Immune system: 免疫系统