|Scientific Name:||Afrixalus knysnae|
|Species Authority:||(Loveridge, 1954)|
|Taxonomic Notes:||This species is closely related to Afrixalus spinifrons (Cope 1862). Species boundaries in this complex are uncertain and taxonomic studies using calls, morphology and genetics are necessary.|
|Red List Category & Criteria:||Endangered B1ab(ii,iii,iv,v) ver 3.1|
|Assessor/s:||South African Frog Re-assessment Group (SA-FRoG), IUCN SSC Amphibian Specialist Group|
|Reviewer/s:||Angulo, A. & Menegon, M.|
|Contributor/s:||Channing, A., Turner, 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 Extent of Occurrence being 1,756 km2, its distribution being severely fragmented (no one site holds >50% of individuals and the distances between subpopulations are considered to be too great for dispersal within one generation) with all individuals in 7 locations, and a continuing decline in the quality of its habitat, area of occupancy, number of locations and number of mature individuals.
This species is known from around 7 locations at low altitude (South Africa on either side of the border between the Eastern Cape and Western Cape Provinces. Extent of Occurrence is 1,756 km² and the Area of Occupancy has not been formally calculated but is known to be declining as some sites (e.g. Covie) which are presumed lost as no adults or tadpoles have been found there for at least three years. Although some sites are pristine, others are threatened by alien vegetation.
Native:South Africa (Eastern Cape Province, Western Cape)
|Range Map:||Click here to open the map viewer and explore range.|
The spatial distribution of this species is considered to be severely fragmented as no one site holds >50% of individuals and the distances between subpopulations are considered to be too great for dispersal within one generation. Visits to one site at Covie have not produced any individuals (adults or tadpoles) for three years. It seems likely that this subpopulation has become extinct, but further visits are required to substantiate this. The cause for this disappearance is as yet unknown, but change in water quality is suspected as a possible reason.
|Habitat and Ecology:||
It lives in a coastal mosaic of vegetation types, including mountain fynbos heathland, and forest. It breeds in small dams and shallow semi-permanent water with much emergent vegetation and even in well vegetated ornamental garden ponds. It is suspected that this species requires high water quality for breeding. Habitat is declining due to encroachment by urban development, alien invasive vegetation and chemical pollution. Species in this genus deposit between 20 and 50 eggs on vegetation above the water. Tadpoles emerge, drop into the water and remain there until metamorphosis.
|Major Threat(s):||The main threat is habitat loss due to urban and recreational development, afforestation, invasive vegetation, agricultural expansion and chemical pollution. These threats are likely to act locally on breeding sites. Drought may cause additional stresses for this species.|
|Conservation Actions:||This species ranks amongst the highest in the need for conservation orientated research within South African threatened frogs. The taxonomy of the species complex is in need of comprehensive review. Important questions are still unanswered concerning the call and tadpoles of this species. There is a definite need to identify management areas, describe breeding phenology, and to identify direct threats; in particular, the effects of changes in water quality at sites with this species need to be documented. The Area of Occupancy needs to be calculated as well as an assessment of the health of all known sites. Once this has been achieved, monitoring at known breeding sites should be instigated. It occurs in Tsitsikamma National Park, Goukamma Nature Reserve, and Diepwalle Forestry Area.|
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.
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.
Passmore, N.I. and Carruthers, V.C. 1995. South African Frogs, 2nd Edition. Southern Book Publishers and Witwatersrand University Press, Johannesburg.
Pickersgill, M. 1996. A new subspecies of Afrixalus from KwaZulu-Natal, South Africa, and comments on its superspecies affinities. Durban Museum Novitates: 49-59.
Pickersgill, M. 2000. The ethology and systematics of eastern and southern African savanna Afrixalus (Anura: Hyperoliidae). Unpublished MSc thesis, University of Leeds.
Pickersgill, M. 2007. Frog Search. Results of Expeditions to Southern and Eastern Africa. Edition Chimaira, Frankfurt am Main.
Schiøtz, A. 1999. Treefrogs of Africa. Edition Chimaira, Frankfurt am Main.
|Citation:||South African Frog Re-assessment Group (SA-FRoG), IUCN SSC Amphibian Specialist Group 2010. Afrixalus knysnae. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 17 April 2014.|