It will take DNA analysis to tell whether these organisms are the same species. Next to nothing is known about chytrid fungi. Aquatic organisms that decompose plant and animal material, they are found around the world, though not usually at high concentrations. To figure out if certain kinds of frogs were more vulnerable to the disease, she correlated mortality rates at her sites with species' reproductive behavior and habitat. Because water permeates the rainforest ecosystem, she explains, frogs are much more diverse in the tropics than in temperate regions.
Some tadpoles hatch on land and then are transported to streams by their parents.
Virtually all of these species have disappeared. Species that are hanging on lay their eggs in the forest, in pools or leaf litter. They either have no tadpole stage, or the tadpoles grow to adulthood away from the streams. This pattern has been confirmed at other sites in Costa Rica and in Australia as well. But that finding, though important, doesn't explain the frogs' susceptibility.