|Scientific Name:||Xenopus gilli|
|Species Authority:||Rose & Hewitt, 1927|
|Taxonomic Notes:||A deep genetic split characterises the disjunct distribution of this species.|
|Red List Category & Criteria:||Endangered B1ab(i,iii)+2ab(i,iii) ver 3.1|
|Assessor(s):||South African Frog Re-assessment Group (SA-FRoG), IUCN SSC Amphibian Specialist Group|
|Reviewer(s):||Angulo, A. & von May, R.|
|Contributor(s):||Channing, 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.|
Listed as Endangered in view of its declining extent of occurrence currently being 1,450 km2, and area of occupancy of 14.5 km2, with all individuals in four locations, and a continuing decline in the extent and quality of its habitat.
|Previously published Red List assessments:||
|Range Description:||This species is endemic to extreme south-western South Africa, occurring on the Cape Peninsula and the south-western Cape coast. It is a low-altitude species occurring at 10-140 m asl; currently known populations occur within 10 km of the coast. Its extent of occurrence (EOO) is estimated to be 1,450 km2, is considered to be declining, and its area of occurrence is estimated to be 1% of the EOO.|
Native:South Africa (Western Cape)
|Estimated area of occupancy (AOO) - km2:||14.5|
|Continuing decline in extent of occurrence (EOO):||Yes|
|Number of Locations:||4|
|Lower elevation limit (metres):||10|
|Upper elevation limit (metres):||140|
|Range Map:||Click here to open the map viewer and explore range.|
The spatial distribution of this species is not considered to be severely fragmented as one subpopulation/location holds >50% of individuals, however the distances between subpopulations of around 100 km is considered to be too great for dispersal within one generation. It appears to be relatively abundant in some of the known localities.
|Current Population Trend:||Unknown|
|Habitat and Ecology:||It is found only in black, acid water in Cape fynbos heathland. It is a winter breeder (July to October). It aestivates if waterbodies dry up. It does not tolerate alteration of its habitat, and the larvae are very sensitive to changes in water quality.|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Use and Trade:||There are no reports of this species being utilized.|
|Major Threat(s):||The main threats are habitat loss due to urbanization, agricultural run-off, and the effects of spreading alien plants. It may be threatened by hybridization with X. laevis, and there have been concerns about how many populations of this species represent pure X. gilli. X. laevis does not favour the acid water that X. gilli requires.|
|Conservation Actions:||Research priorities for this species include estimating dispersal capabilities, identification of management units and monitoring population size. The threat of hybridisation needs to be clarified, as Xenopus laevis now occurs throughout the range. Habitat management and restoration are needed. It occurs in Cape Peninsula National Park and Agulhas National Park, both of which are relatively well managed, although there is a need to control the spread of invasive plants within these areas.|
1996. The Biology of Xenopus. Zoological Society of London, Clarendon Press, London.
Baard, E.H.W. 1989. The status of some rare and endangered endemic reptiles and amphibians of the southwestern Cape Province, South Africa. Biological Conservation: 161-168.
Channing, A. 2001. Amphibians of Central and Southern Africa. Cornell University Press, Ithaca and London.
du Preez, L. and Carruthers, V. 2009. A complete guide to the frogs of southern Africa. Struik Nature, Cape Town.
Evans, B.J., Morales, J.C., Picker, M.D., Kelley, D.B. and Melnick, D.J. 1997. Comparative molecular phylogeography of two Xenopus species, X. gilli and X. laevis, in the south-western Cape Province, South Africa. Molecular Ecology: 333-343.
Evans, B.J., Morales, J.C., Picker, M.D., Melnick, D.J. and Kelley, D.B. 1998. Absence of extensive introgression between Xenopis gilli and Xenopus laevis laevis in the southwestern Cape Province, South Africa. Copeia: 504-509.
IUCN. 2004. 2004 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 23 November 2004.
IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.3). Available at: http://www.iucnredlist.org. (Accessed: 2 September 2010).
Minter, L.R., Burger, M., Harrison, J.A., Braack, H.H., Bishop, P.J. and Knoepfer, D. 2004. Atlas and Red Data Book of the Frogs of South Africa, Lesotho and Swaziland. SI/MAB Series No. 9, Washington, D.C.
Picker, M.D. and de Villiers, A.L. 1989. The distribution and conservation status of Xenopus gilli (Anura: Pipidae). Biological Conservation: 169-183.
Picker, M.D., Harrison, J.A. and Wallace, D. 1996. Natural hybridisation between Xenopus laevis laevis and X. gilli in the south-western Cape Province, South Africa. In: Tinsley, R.C. and Kobel, H.R. (eds), The Biology of Xenopus, pp. 61-71. Zoological Society of London, Oxford.
Picker, M.D., McKenzie, C.J. and Fielding, P. 1993. Embryonic tolerance of Xenopus (Anura) to acidic blackwater. Copeia: 1072-1081.
Rau, R.E. 1978. The development of Xenopus gilli Rose & Hewitt (Anura, Pipidae). Annals of the South African Museum: 247-263.
Simmonds, M.P. 1985. Interactions between Xenopus species in the south-western Cape Province, South Africa. South African Journal of Science: 200.
Vigny, C. 1979. The mating calls of 12 species and sub-species on the genus Xenopus (Amphibia: Anura). Journal of Zoology: 103-122.
|Citation:||South African Frog Re-assessment Group (SA-FRoG), IUCN SSC Amphibian Specialist Group. 2010. Xenopus gilli. The IUCN Red List of Threatened Species 2010: e.T23124A9417597. . Downloaded on 26 November 2015.|
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