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Afrixalus knysnae 

Scope: Global
Language: English
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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Amphibia Anura Hyperoliidae

Scientific Name: Afrixalus knysnae (Loveridge, 1954)
Common Name(s):
English – Knysna Leaf-folding Frog, Knysna Banana Frog, Knysna Spiny Reed Frog
Synonym(s):
Afrixalus brachycnemis knysnae Poynton, 1964
Hyperolius knysnae Loveridge, 1954
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.
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.

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(i,ii,iii,v)+2ab(i,ii,iii,v) ver 3.1
Year Published: 2016
Date Assessed: 2016-07-29
Assessor(s): IUCN SSC Amphibian Specialist Group & South African Frog Re-assessment Group (SA-FRoG)
Reviewer(s): Luedtke, J.
Contributor(s): Channing, A., Rebelo, A., Turner, A.A., de Villiers, A., Becker, F., Harvey, J., Tarrant, J., Measey, J., Tolley, K., Minter, L., du Preez, L., Burger, M., Cunningham, M., Baptista, N., Hopkins, R., Davies, S., Conradie, W. & Chapeta, Y.
Facilitator/Compiler(s): Rebelo, A., Measey, J. & Neam, K.
Justification:
Listed as Endangered, in view of its extent of occurrence being 816 km2, the area of occupancy being 27 km2, with all individuals in five locations, and a continuing decline in the quality of its habitat, area of occupancy, and number of mature individuals.
Previously published Red List assessments:

Geographic Range [top]

Range Description:

This species is known from around five locations at low altitudes, on either side of the border between the Eastern Cape and Western Cape Provinces in South Africa. This species was rediscovered at Covie in 2011, where it was previously not found for four years and thought to be extinct from that location (W. Conradie pers. comm. August 2016). It occurs up to 300 m asl, its extent of occurrence (EOO) is 816 km2, and its area of occupancy (AOO) is 27 km2.

Countries occurrence:
Native:
South Africa (Eastern Cape Province, Western Cape)
Additional data:
♦ Estimated area of occupancy (AOO) - km2:27.11♦ Continuing decline in area of occupancy (AOO):Yes
♦ Extreme fluctuations in area of occupancy (AOO):No♦ Estimated extent of occurrence (EOO) - km2:815.61
♦ Continuing decline in extent of occurrence (EOO):Yes♦ Extreme fluctuations in extent of occurrence (EOO):No
♦ Number of Locations:5♦ Continuing decline in number of locations:No
♦ Extreme fluctuations in the number of locations:No
♦ Upper elevation limit (metres):300
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:

The spatial distribution of this species is not 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. There are four known subpopulations (L. du Preez pers. comm. August 2016). Only the Groenvlei subpopulation is a fairly large site, whereas the other sites are tiny waterbodies (L. du Preez pers. comm. August 2016). At Groenvlei, the frogs are concentrated in a few reed beds along the periphery (L. du Preez pers. comm. August 2016). The Saasveld and Groenvlei subpopulations are relatively stable, but the other sites are being degraded and the species is suspected to be decreasing at these locations (L. du Preez pers. comm. August 2016). Visits to six historic sites indicated that five of these no longer exist or are not suitable. Specifically, the Crags sites have been degraded to the extent that most of them no longer contain suitable habitat (L. du Preez pers. comm. August 2016). Ongoing studies will attempt to determine the viability and dispersal potential between sites (L. du Preez pers. comm. October 2015). 

Current Population Trend:Decreasing
Additional data:
♦ Continuing decline of mature individuals:Yes
♦ Extreme fluctuations:No♦ Population severely fragmented:Yes

Habitat and Ecology [top]

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. Species in this genus deposit between 20 and 50 eggs on vegetation above water, folded in a grass leaf. Tadpoles emerge, drop into the water and remain there until metamorphosis.

Systems:Terrestrial; Freshwater
Continuing decline in area, extent and/or quality of habitat:Yes
Movement patterns:Not a Migrant

Use and Trade [top]

Use and Trade:

There are no reports of this species being utilized.

Threats [top]

Major Threat(s): Although some known sites are pristine, others are threatened by habitat loss due to urban and recreational development, afforestation, invasive vegetation, agricultural expansion, chemical pollution, and livestock. These threats are likely to negatively affect breeding sites. habitat loss is the primary threat. 

The sites at Saasveld Groenvlei do not seem to have been impacted too severely, but the other sites are being degraded; the Crags sites have been seriously degraded to the extent that most of the historic sites no longer are suitable (L. du Preez pers. comm. August 2016). Livestock is a huge problem in the Covie and especially the Crags sites as these sites are used by cattle as drinking holes: this is an intensive milk producing area and the cattle destroy the vegetation these frogs need to breed (L. du Preez pers. comm. August 2016). Pollution in the form of urine and faeces from cattle, together with trampling, adds to habitat loss (L. du Preez pers. comm. August 2016). Drought may cause additional stressors for this species.

Conservation Actions [top]

Conservation Actions: Conservation Actions
It occurs in Tsitsikamma National Park, Goukamma Nature Reserve, and Diepwalle Forestry Area. An assessment of the health of all known sites is ongoing (L. du Preez pers. comm. October 2015). Once this has been achieved, monitoring at known breeding sites should be instigated. 

Conservation Needed
This species ranks amongst the highest in the need for conservation orientated research within South African threatened frogs (Measey 2011). In the light that many of the sites are so small, there is a need to take action to preserve these sites (L. du Preez pers. comm. August 2016). Control of invasive vegetation is imperative for this species' survival. 

Research Needed
The taxonomy of the species complex is in need of comprehensive review (Channing et al. 2011). Important questions are still unanswered concerning the call and tadpoles of this species, as well as its breeding phenology. There is a definite need to identify management areas and direct threats; in particular, the effects of changes in water quality at sites with this species need to be documented. There is also a need to study the feasibility of restoring historical sites.
Citation: IUCN SSC Amphibian Specialist Group & South African Frog Re-assessment Group (SA-FRoG). 2016. Afrixalus knysnae. The IUCN Red List of Threatened Species 2016: e.T56065A77160768. . Downloaded on 26 September 2018.
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