|
|---|
Warning: Undefined property: stdClass::$Photo1 in /var/www/vhosts/virtualzoo/classifications/display.php on line 584
| Subspecies: | Unknown |
|---|---|
| Est. World Population: | |
| CITES Status: | NOT LISTED |
| IUCN Status: | Endangered |
| U.S. ESA Status: | NOT LISTED |
| Body Length: | |
| Tail Length: | |
| Shoulder Height: | |
| Weight: | |
| Top Speed: | |
| Jumping Ability: | (Horizontal) |
| Life Span: | in the Wild |
| Life Span: | in Captivity |
| Sexual Maturity: | (Females) |
| Sexual Maturity: | (Males) |
| Litter Size: | |
| Gestation Period: | |
Habitat:
Adults of this species generally occur in both forest and fynbos biomes, breeding in clear perennial headwater mountain streams in ravines on Table Mountain. Adults are found in damp, sheltered habitat next to streams and have also been found well away from streams, including in caves and under rocks. Adults typically select elevated, inaccessible rock cracks. Tadpoles have a large oral disc that allows them to adhere to rocks, streamlined bodies and a wedge-shaped head enabling them to inhabit steeply sloped, fast flowing streams. They rely on sediment free pools with low embeddedness and an abundance of large substrates that provide pore-space refugia (i.e. gaps under/between pebbles and boulders). Tadpoles utilize these spaces to hide and feed, and retreat to them during periods of high winter flow. Tadpoles require longer than 12 months to complete metamorphosis (Weeber et al. 2023), and perennial stream flow is therefore important.
Range:
This species has a very restricted range and is endemic to the southern and eastern slopes of Table Mountain, in the Western Cape province, extreme southwestern South Africa, between 240–1,060 m asl. It was historically recorded from seven streams but is currently known to occur in only five streams that are considered to have a viable number of breeding adults (Skeleton, Windows, Upper Disa, Disa, Original Disa). Recent surveys support previous work showing the species is no longer present in Platteklip Gorge and Cecilia streams (Weeber et al. 2023), confirming that it has been locally extirpated there for decades (Minter et al. 2004, Weeber et al. 2023). Its extent of occurrence (EOO) is 23 km2. In addition, there are four streams (Valley of the Red Gods, Nursery, Myburgh's Waterfall Ravine, and Hiddingh Ravine) in which tadpoles occur in very low densities in sub-optimal habitat, and breeding is likely sporadic (i.e. not every year). These streams have lower flow and are likely prone to drying up during particularly low rainfall years. They are considered sink populations. Historical records from Valley of the Red Gods probably refer to upper Disa records.
The location and source of known threats are diverse and the species is therefore considered to occur at two to four threat-defined locations.
The location and source of known threats are diverse and the species is therefore considered to occur at two to four threat-defined locations.
Conservation:
Conservation Actions In-Place
Most of the range is incorporated in the Table Mountain National Park, which is believed to protect more than 99% of the species' overall distribution, with the rest on the estate of Kirstenbosch National Botanic Gardens (South African National Biodiversity Institute) which has no special protection. The species has been considered Endangered since 1998 (and Critically Endangered since 2004). Since 2019 the species was in an intensive monitoring programme that assessed tadpole distribution across the species range and modelled tadpole presence against environmental covariates, linking results to threat locations and impacts. Research and monitoring are being carried out to estimate population size through occupancy modelling, and to establish whether there is connectivity between streams using genetic analyses. Each stream is also being systematically surveyed over their entire lengths to record presence/absences. The monitoring of tadpole populations and threats to stream habitat will continue.
Conservation Needed
Hiking paths on Table Mountain need to be actively managed to mitigate erosion and localised habitat degradation. This involves the installation of boardwalks in areas where paths bisect streams, stabilising paths that run alongside stream banks, the permanent closure of paths that are routed directly within the stream channel and potentially limiting the numbers of users. Alien vegetation, particularly species such as Deciduous Grey Poplars (Populus x canescens) and Australian Blackwood (Acacia melanoxylon) that grow in the stream channel, should be removed, and monitored for follow-up annually. It is recommended that water abstraction from weirs situated in reservoir-fed streams is limited to the winter months of May through August, when high run-off and discharge buffers the impact of abstraction. Reservoirs and weirs should be left open outside this suggested time window, specifically during late summer to ensure that the first wet season rain drains naturally into streams and is not caught by reservoirs and weirs. Rehabilitation actions should focus on Cecilia Gorge.
Research Needed
Tadpole monitoring should continue using the methods outlined in Weeber et al. (2023). Detailed, long-term discharge estimates should be recorded for all streams to build a baseline of hydrological data. This will enable researchers to monitor changes in flow and calculate current ecological reserves to inform stream management and abstraction. Acoustic monitoring of breeding adults would assist with tadpole monitoring and could also be used to estimate the population of breeding adults.
Most of the range is incorporated in the Table Mountain National Park, which is believed to protect more than 99% of the species' overall distribution, with the rest on the estate of Kirstenbosch National Botanic Gardens (South African National Biodiversity Institute) which has no special protection. The species has been considered Endangered since 1998 (and Critically Endangered since 2004). Since 2019 the species was in an intensive monitoring programme that assessed tadpole distribution across the species range and modelled tadpole presence against environmental covariates, linking results to threat locations and impacts. Research and monitoring are being carried out to estimate population size through occupancy modelling, and to establish whether there is connectivity between streams using genetic analyses. Each stream is also being systematically surveyed over their entire lengths to record presence/absences. The monitoring of tadpole populations and threats to stream habitat will continue.
Conservation Needed
Hiking paths on Table Mountain need to be actively managed to mitigate erosion and localised habitat degradation. This involves the installation of boardwalks in areas where paths bisect streams, stabilising paths that run alongside stream banks, the permanent closure of paths that are routed directly within the stream channel and potentially limiting the numbers of users. Alien vegetation, particularly species such as Deciduous Grey Poplars (Populus x canescens) and Australian Blackwood (Acacia melanoxylon) that grow in the stream channel, should be removed, and monitored for follow-up annually. It is recommended that water abstraction from weirs situated in reservoir-fed streams is limited to the winter months of May through August, when high run-off and discharge buffers the impact of abstraction. Reservoirs and weirs should be left open outside this suggested time window, specifically during late summer to ensure that the first wet season rain drains naturally into streams and is not caught by reservoirs and weirs. Rehabilitation actions should focus on Cecilia Gorge.
Research Needed
Tadpole monitoring should continue using the methods outlined in Weeber et al. (2023). Detailed, long-term discharge estimates should be recorded for all streams to build a baseline of hydrological data. This will enable researchers to monitor changes in flow and calculate current ecological reserves to inform stream management and abstraction. Acoustic monitoring of breeding adults would assist with tadpole monitoring and could also be used to estimate the population of breeding adults.




