Once a vulnerable amphibian living on mountain peaks of the south-western Cape, Rose’s mountain toadlet’s (Capensibufo rosei) conservation status has changed almost overnight.
Words by René de Klerk. Originally published in SANParks Times.
Its status skyrocketed to “critically endangered” in September – all because of the discovery that population outside of Table Mountain National Park are genetically different enough from the original population to be a separate species.
The results of DNA tests done on populations found on peaks of the Cape Folded Mountains, of what was thought to be the same species, revealed significant genetic differences between four mountain toad linages. Because of this, three new frog names were needed, with the original populations on the Cape Peninsula retaining the old name.
The new names and species descriptions were a collaboration between CapeNature, Stellenbosch University, North-West University, and the South African National Biodiversity Institute (Sanbi). They are the Deception Peak Mountain Toadlet (Capensibufo deceptus), the Landdroskop mountain toadlet (Capensibufo magistratus), and the moonlight mountain toadlet (Capensibufo selenophos).
“This means the population found in the park is now recognised as the only population in the world,” says Zishan Ebrahim, biodiversity data scientist at the SANParks Cape Research Centre. “It might seem like one more species became critically endangered under our watch, which is not the case,” says Ebrahim. Rather, the past assumption of a larger distribution was false. Much like the Table Mountain Ghost Frog, it occurs in an area less than 100 km2. Because of this and threats to their habitat, they are now listed as Critically Endangered.
There have been some interesting observations pertaining to these frogs. “Since the 2015 fires, tadpole numbers are higher,” says Ebrahim. While Sanbi monitors them, park management has been micro-managing sites where they occur. This entails closing footpaths during the breeding season as the puddles used for breeding are generally in these paths. “Adults go to the same area where they were born, so these puddles are generally quite reliable and interconnected,” says Ebrahim.
“One of our biggest tasks now is trying to find out if there are more than just the known subpopulations in the park. But there are challenges with this,” Ebrahim says.
The dwarf mountain toad is known to have no functional hearing. They also don’t call out like other frogs, so it is very difficult to locate them.
The easiest way to find them is by tracing their recorded locations. Rose’s mountain toad breeds in shallow puddles, generally in areas where water would only stand for around two weeks. However, a general lack of fire and a shortage of the trampling disturbance of hooved animals have been a detriment to them, says Ebrahim. “They need the vegetation to be cleared from time to time to open up their breeding areas,” he says.
Other management options to benefit the frogs include burning old vegetation, clearing vegetation when this is not possible or even introducing more wildlife to encourage the clearing of senescent or overgrown vegetation and the trampling of compacted soils.