|Scientific Name:||Hyperolius pickersgilli Raw, 1982|
|Taxonomic Source(s):||Frost, D.R. 2016. Amphibian Species of the World: an Online Reference. Version 6.0 (31 March 2016). New York, USA. Available at: http://research.amnh.org/herpetology/amphibia/index.html.|
|Red List Category & Criteria:||Endangered B1ab(ii,iii)+2ab(ii,iii) ver 3.1|
|Assessor(s):||IUCN SSC Amphibian Specialist Group & South African Frog Re-assessment Group (SA-FRoG)|
|Contributor(s):||Channing, A., Rebelo, A., Turner, A.A., de Villiers, A., Harvey, J., Tarrant, J., Measey, J., Tolley, K., Minter, L., du Preez, L., Burger, M., Cunningham, M., Davies, S., Hopkins, R., Conradie, W. & Chapeta, Y.|
|Facilitator/Compiler(s):||Rebelo, A., Measey, J., Neam, K. & Hobin, L.|
Listed as Endangered because its extent of occurrence (EOO) is 4,768 km2, area of occupancy (AOO) is 12 km2, its distribution is severely fragmented, and there is continuing decline in its AOO and the extent and quality of habitat.
|Previously published Red List assessments:|
|Range Description:||This species is endemic to the coast of KwaZulu-Natal Province, South Africa, and is found within 15 km of the coast up to 380 m asl. It was previously thought to range from Warner Beach in the south to St Lucia village in the north; however, it has now been recorded from additional localities and occurs from Sezela to St Lucia village (Tarrant and Armstrong 2013). Given the distribution of existing subpopulations, there are 12 threat-defined locations. Its extent of occurrence (EOO) is 4,768 km2 and its area of occupancy (AOO) is 12 km2.|
Native:South Africa (KwaZulu-Natal)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The spatial distribution of this species is considered to be severely fragmented due to coastal development in the past three decades, more than 50% of individuals are in small and isolated patches and more than 50% of subpopulations are considered non-viable. Increased survey effort has verified the status of historical sites and confirmed the presence of the species at a total of 22 localities (Tarrant and Armstrong 2013). However, only three of these occur in protected areas and the remainder are at threat of degradation or loss. |
Initial results from a population genetics study based on mitochondrial DNA sequencing and microsatellite genotyping of samples from 12 localities, representing six subpopulations, indicate that gene flow between the subpopulations is not restricted and there is relatively high genetic diversity between subpopulations (D.L. Dalton et al. unpubl. data). These results likely represent a historical ability to migrate, which is now severely hampered in the current landscape (J. Tarrant pers. comm. August 2016). Two subpopulations were identified with a high degree of admixture with other subpopulations. However, various analyses found the observed population structure to be weak, a common trend found in amphibian populations in small geographic scales with limited distributions (J. Tarrant pers. comm. August 2016). Additional sampling is required from these subpopulations as well as the remainder for which no samples were obtained.
|Current Population Trend:||Unknown|
|Habitat and Ecology:||The species is a habitat specialist occurring primarily in Indian Ocean Coastal Belt Vegetation Group 2, which is Critically Endangered and poorly protected. It requires perennial wetlands comprised of very dense reed beds at low altitudes (Raw 1982, Armstrong 2001, Bishop 2004). It also requires an understory of thick vegetation, such as Snakeroot (Persicaria attenuata), from which males call and taller broad-leaved vegetation, including the Common Reed (Phragmites australis), Bulrushes (Typha capensis), and sedges (including Cyperus dives, C. latifolius and C. papyrus) on which to lay its eggs (Raw 1982, Bowman 2011, Tarrant and Armstrong 2013). It is associated with deeper areas of water within wetland systems (20-80 cm) (Trenor 2014). It is seldom found at the same breeding sites as the abundant Hyperolius marmoratus.|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Use and Trade:||There are no records of this species being utilized.|
Less than 1% of this species' range is currently estimated to fall within protected areas (Armstrong 2001). It is threatened primarily by habitat loss caused by urbanisation, afforestation and drainage for agricultural and urban development and more recently by dune mining and large-scale industrial developments. The increased spread of alien vegetation is responsible for the degradation of several breeding sites. The amphibian chytrid fungus, Batrachochytrium dendrobatidis, has been detected in some subpopulations and is an important consideration for proposed captive breeding and translocation plans (Tarrant et al. 2013).
Many of the historically known sites have been eliminated by either sugar cane or eucalyptus plantations, which directly impact on breeding habitat through wetland drainage and planting within wetland buffers, and cause a drying out of wetland areas (Johnson and Raw 1987, Bishop 2004). Two large reedbed areas (known localities), which in 2015 were in good condition, have since been drained for agriculture by the local communities, essentially rendering those wetlands completely transformed (J. Tarrant pers. comm. August 2015). It has not yet been verified whether the species still persists there.
This species occurs in the iSimangaliso Wetland Park, the Umlalazi Nature Reserve, Ongoye Forest Reserve and the Twinstreams-Mtunzini Natural Heritage Site.
Following a period in which little research was done on H. pickersgilli, recent years have seen increasing research attention being paid to this threatened species which has included obtaining accurate information on threats and determining the status of all sites and estimating population size. Such research will benefit conservation actions. Specific recent research projects have included surveys of distribution and development of a predictive model to guide additional surveys (Tarrant and Armstrong 2013), and a study done on the potential impact of noise from airplanes landing at King Shaka International Airport on the Mount Moreland population (Kruger et al. submitted).
At the Amphibian Species Prioritisation Workshop held in Johannesburg in 2008, H. pickersgilli was identified as a species requiring ex situ rescue and supplementation. An ex-situ breeding programme was initiated by the Johannesburg Zoo in January 2012 with the collection of 30 individuals from two sites (Mount Moreland and Isipingo). Since then, SAAMBR has coordinated the APP (African Preservation Programme) for this species under the auspices of PAAZAB). The National Zoological Gardens in Pretoria are also involved. The first aim of the ex-situ breeding programme is to develop correct husbandry practices for the species. Ultimately the goal is to have the ex-situ component contributing to the overall conservation of the species through supplementation and establishing viable populations in the wild.
In-situ research initiated by NWU in 2008 on H. pickersgilli coincided with the prioritisation of the species for ex-situ work. As a continuation of the NWU research, The Endangered Wildlife Trust’s Threatened Amphibian Programme (EWT-TAP) was initiated and the programme has included H. pickersgilli as a priority species for conservation action. Alien clearing and restoration work is now underway for four known sites in the eThekwini area, including “Froggy Pond” at Mount Moreland, which hosts the largest population outside of a protected area, and is some of the last remaining intact Indian Ocean Coastal Belt wetland habitat. This site is receiving increased conservation attention and is on track to becoming an officially protected area. Discovery of the species at another site on the south coast has resulted in the prevention of a proposed development there and will be receiving improved management and monitoring. Other conservation actions include the development of Biodiversity Management Plan, ongoing surveys, development and testing of a monitoring protocol, a population genetics study and an ongoing awareness and education campaign.
Land owner agreements are also in the process of being drawn up for protection and management of all sites for conservation management.
Research is still required to determine population sizes, life history and ecology (in particular dispersal potential), followed by appropriate monitoring of both population and habitat (for which monitoring protocols have been developed and tested).
|Citation:||IUCN SSC Amphibian Specialist Group & South African Frog Re-assessment Group (SA-FRoG). 2016. Hyperolius pickersgilli. The IUCN Red List of Threatened Species 2016: e.T10644A77165927.Downloaded on 15 December 2017.|