PRETORIA – The Department of Environmental Affairs (DEA), Ezemvelo KZN Wildlife (EKZNW)) and the Johannesburg Zoo this week released the second batch of captive-bred endangered Pickersgill’s Reed Frogs (Hyperolius pickersgilli), at River Horse Valley in eThekwini, KwaZulu-Natal.
The team that led the re-introduction of about 50 frogs on 5 March 2019 was headed by Ian du Plessis, the Curator of the Project to reintroduce the amphibians back into their former habitat at the Johannesburg Zoo. He was supported by scientists from Ezemvelo KZN Wildlife, the Endangered Wildlife Trust (EWT) and the Department of Environmental Affairs.
Ezemvelo KZN Wildlife initiated this ground-breaking programme by requesting the Johannesburg Zoo to breed a sustainable insurance population of the species.
The project has included collecting wild specimens and breeding them at the zoo.
Building on programmes
About 200 captive-bred offspring were released in the Mount Moreland and Prospecton areas – a first for South Africa – on 17 September 2018.
Over the past decade, EKZNW has engaged with other government departments, parastatals, municipalities and conservancies to ensure that the Pickersgill’s Reed Frog population is restored and the species brought back from the brink of extinction.
This approach followed the deadly outbreak of the Chytrid fungi (Batrachochytrium dendrobatidis) in the early 2000s, leading to the death of amphibian populations in many parts of the world.
The two releases meet a goal of the Pickersgill’s Reed Frog Biodiversity Management Plan to improve the conservation status of the species so that it can eventually be downlisted to Least Concern.
Also, to improve its protection as part of meeting international biodiversity objectives such as the Aichi targets through applied conservation action.
Red list longer and longer
Amphibians play integral roles in most ecosystems and are presently the most threatened Class of vertebrates globally, with approximately one-third of all known species Red Listed by the IUCN.
This situation is reflected in South Africa, with 30% of the country’s frog species listed under a threatened category.
Overall, 43% of South African frog species are endemic to the country. Of these, 35% are in a threatened category. And all but one of the threatened species are endemics.
The highest species richness for frogs occurs in KwaZulu-Natal. This area has been recognised as being important for both frog endemism and having high levels of human activity, particularly in the coastal regions.
Pickersgill’s Reed Frog is a small frog known only from limited and highly fragmented coastal wetland habitat in KwaZulu-Natal, mostly commercially-owned land.
Without concerted pro-active conservation intervention, it is highly likely that the species will become extinct.
The Pickersgill’s Reed Frog is listed on the International Union for Conservation of Nature (IUCN) Red Data List and by South Africa’s Threatened or Protected Species (TOPS) Regulations of the National Environmental Management: Biodiversity Act as Endangered.
The species is KwaZulu-Natal’s only amphibian species with this status.
Threats include habitat loss as a result of wetland drainage or destruction for agricultural, urban and industrial development; severe habitat fragmentation; alien vegetation and afforestation resulting in drying out of breeding sites and pollution from pesticides and other contaminants.