Darwin’s frog, a 3cm long species named after Charles Darwin, who first discovered it in 1834, lives in the temperate forests of Chile and Argentina at altitudes of 50-1500 metres above sea level. It is one of only two species of frog in this region that exhibit extremely specialised methods of brooding their young (the other being Chile Darwin’s frog, which is thought to be extinct). After a female R. darwinii has laid eggs on moist ground, the male then swallows them and they develop protected in his vocal sac until ready to emerge, at which point he sort of coughs young, fully formed frogs out of his mouth.
In 2010 the IUCN classified Darwin’s frog as vulnerable. However, more recent research has yielded far more worrying statistics. In the northern part of the Darwin’s frog’s range, its habitat has been converted to non-native tree plantations and the species has disappeared from some locations. Its decline further south has been linked to the deadly chytrid fungus, responsible for the decimation of amphibian populations around the globe and widely attributed to climate change. Chytridiomycosis is caused by the fungus Batrachochytrium dendrobatidis and its spread is largely attributed to the pet and food trade, an epidemic that can only be controlled by quarantines and trade restrictions – there is no cure for chytridiomycosis nor can it be eradicated from wild populations.
The IUCN has called the fungus ‘the worst infectious disease ever recorded among vertebrates in terms of the number of species impacted and its propensity to drive them to extinction.’
Surveys conducted between 2008-2012 concluded that the population of Darwin’s frog is extremely small and fragmented and it is now only found at 36 out of 233 of its previously known sites. Many of these sites occur on protected land but quality of maintenance of the areas varies. Given that we have already witnessed the extinction of Chile Darwin’s frog, the scientific community is not ready to give up hope for the species and conservation and research methods continue to be explored.