A new subpopulation of the critically endangered Micro Frog (Microbatrachella capensis) has been found in the wetlands in the Nuwejaars Wetlands Special Management Area (NWSMA).
The Micro Frog is a tiny species, about the size of a person’s thumbnail when fully grown. It was previously known from just four subpopulations between the Cape Flats and the southern tip of Africa. Scientists say if you combine the total area that this amphibian species occupies in the world, it amounts to just 7 km².
The Micro Frog is critically endangered due to this very small range, as well as the habitat lost or degraded as a result of urbanisation, agricultural expansion and invasive alien vegetation.
This discovery appears to show a previously unknown subpopulation, making it only the fifth left in the world.
It also seemingly indicates that the Agulhas Plain is a stronghold for the species, with another subpopulation found in the neighbouring Agulhas National Park.An unexpected find
The army of around 30 individual frogs was discovered by University of Stellenbosch student, Oliver Angus, working with the conservation team at the Nuwejaars Wetlands Special Management Area.
Oliver says: “This find was completely unexpected. We were actually searching for Cape Platanna when we found the Micro Frog. This is an awesome find for the species: this is a whole new catchment for them, and it’s a 20 km range extension.”
NWSMA Project Manager, Ross Kettles, says there have also been other exciting discoveries in wetlands and rivers here.
“During our monitoring activities,” says Ross, “we also recently found a number of populations of the Endangered Cape Platanna (Xenopus gilli) here. The Cape Platanna is also in trouble – it’s known from only four locations in the world, and is extremely sensitive to habitat change.”
This was the first record of Cape Platanna on the Agulhas Plain.
The NWSMA is an initiative driven by local farmers and the community of Elim close to Africa’s southernmost tip, covering 47 000 ha. Landowners have come together to protect the Nuwejaars wetlands system, considered the largest wetland system in South Africa, and threatened fynbos vegetation and wildlife that occur here. They’ve signed title deed restrictions to protect this area forever.Rehabilitation
The Nuwejaars wetlands system has been described as highly irreplaceable by the South African National Biodiversity Institute.
The wetlands are being cleared of invasive vegetation and rehabilitated in a project funded by WWF South Africa, with co-funding from the Overberg District Municipality, and research and monitoring is funded by the Hans Hoheisen Charitable Trust.
The discoveries of these new species have also caught the eye of amphibian experts.
Dr Jeanne Tarrant of the Endangered Wildlife Trust says of the Micro Frog, “As a Critically Endangered species known from just four subpopulations, and having disappeared from several previous historical localities, this is indeed significant.
“It appears to represent the most inland record of the species and is thus an important range expansion.
“It’s great that the NWSMA provides an additional site where the habitat is well managed,” she stated.