Frogs worldwide are threatened by the chytrid fungus, and many have already gone extinct. However, Australian researchers have a novel idea for how to save one species, which may turn out to be applicable to others. They plan to accelerate their growth to sexual maturity so they breed before getting sick. Thirty endangered northern corroboree frogs are being moved to a semi-wild enclosure at Tidbinbilla Nature Reserve, in the hope they will thrive there before being released into wild sites at the lower end of their altitude range.
In a world increasingly anxious about humans reaching puberty too young, actually encouraging early sexual maturity seems like a non-starter. However, there's probably not a lot of people worried about frogs having sex before they are emotionally suited to it. Moreover, the charismatically colored northern corroboree frog is something of an outlier in how late it breeds, often only making tadpoles at the age of three or four. Dr Ben Scheele of the Australian National University says this is partly about location.
“Although the frogs are found high up in the mountains of Namadgi, we think warmer temperatures at lower sites could give the frogs a helping hand by enabling them to grow faster and breed sooner,” Scheele said in a statement. By releasing northern corroboree frogs at lower locations, Scheele hopes to get them to breed earlier, increasing the chance they can reproduce before the fungus manages to infect them.
Scheele told IFLScience some frog species are coping with the fungus better than others, and it is more often those that live at lower altitudes that are surviving.
Naturally, there is no point introducing frogs into territory that is unsuitable to them, but Scheele told IFLScience the locations he and his colleagues are investigating are similar to other sites where the northern corroboree frog has been found. Scheele added that, fungus aside, the biggest threat to the frog appears to be drought, rather than predators, so the team are looking at sites that maintain sufficient water even in dry years. Sites free of fungus-transmitting frog species are also desired.
The chytrid fungus is killed by dry conditions and temperatures above 28ºC (82ºF), so conservation programs for frogs whose range extends into areas where the fungus can't survive have transplanted them to safe areas. However, Scheele told IFLScience the corroboree frog's entire range is chytrid-susceptible, so something more innovative is needed.
Scheele hopes that if the corroboree frog thrives at the new locations other amphibians will also benefit, both through improved knowledge of why some are resisting the fungus while others succumb, and through the project acting as a model for saving others.