Neamblysomus julianae (Bronberg Ridge subpopulation)
|Scientific Name:||Neamblysomus julianae (Bronberg Ridge subpopulation)|
|Taxonomic Notes:||Assigned to the genus Neamblysomus by Bronner (1995, 2013). Topotypical population (Bronner and Jenkins 2005). Consistent colour and dental differences exist between two western subpopulations (Bronberg Ridge and Modimolle) and the Kruger National Park subpopulation at the eastern limit of its distribution. Ongoing molecular research suggests pronounced genetic partitioning between the Kruger National Park (KNP) and the other two subpopulations (Maree et al. 2003; Jackson et al. 2007a; unpublished data) and that these are potentially distinct species.|
|Red List Category & Criteria:||Critically Endangered B1ab(ii,iii,iv)+2ab(ii,iii,iv) ver 3.1|
|Reviewer(s):||Bennett, N.C. & Taylor, A.|
Treated as a distinct subpopulation, as there are no intermediate locality records or evidence of gene flow between the Bronberg Ridge population east of Pretoria (Tshwane, Gauteng) and the other two geographically isolated populations documented in South Africa (in and around Nylsvley Nature Reserve and Modimolle, Limpopo Province and Numbi Gate, Pretoriuskop and Matjulwana districts in southwestern Kruger National Park, Mpumalanga Province). Localities documented in the Bronberg area do not fall in any national or provincial protected areas. Much of its natural sandy habitat has been dramatically altered, degraded and fragmented as a result of intense urbanization and high-density housing developments along nearly the entire length of its very restricted range (<10 km2) on the Bronberg Ridge, east of Pretoria (Tshwane), Gauteng. Its entire distributional range has been fragmented into four sections by two major roads and a housing development. Quartzite mining operations pose an additional and severe threat of destroying the sole remaining primary east-west dispersal corridor inside the largest intact section of remaining natural habitat (about 7.5 km x 0.9 km). Such impacts are known to lead to genetic erosion (reduced variability and inbreeding) and reduced population viability (also see Conservation Measures). Therefore the reassessment confirms the Critically Endangered status of this subpopulation.
|Previously published Red List assessments:|
This topotypical population is known from only The Willows (type locality), Wapadrand, Shere Agricultural Holdings and Tierpoort on the northern slopes, and Olympus and Zwavelpoort on the southern slopes, of the Bronberg Ridge in eastern Pretoria (Thswane), Gauteng. However, the very restricted ranges of this and the other subpopulations (Nylsvley area and Kruger National Park) are possibly not sufficient to ensure the long-term persistence of the species (Jackson and Robertson 2011).
Native:South Africa (Gauteng)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Locally common, with 2-3 individuals/ha in prime habitat. However, dispersion is patchy and clumped within each subpopulation owing to specialized habitat requirements (e.g. soil characteristics, Jackson et al. 2007b).|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Confined to sandy soils, often pockets of weathered sandstone associated with rocky ridges within Rocky Highveld Grassland vegetation. Also occurs in well-irrigated residential gardens and small-holdings supporting livestock. The size distribution of sand particles influences soil density and compactability, which are positively correlated with the presence of these golden moles and affect energy expenditure during tunnelling (Jackson et al. 2007b). Subsurface foraging tunnels visible as broken ridges on the soil surface; most foraging activity occur within the upper layer (10 20 mm; Bronner and Bennett 2005), mainly in the late afternoon and early evening.|
Much suitable habitat remaining within their very limited range along the Bronberg Ridge is undergoing severe transformation and fragmentation as a result of urbanization and quartzite mining. The size and connectedness of the remaining patches of suitable habitat mainly defines if they can sustain golden moles (Jackson 2007, Jackson et al. 2007a, Jackson and Robertson 2011).
|Continuing decline in area, extent and/or quality of habitat:||Yes|
Inferred major threats are habitat alteration, fragmentation and loss. Much of its natural sandy habitat has been dramatically altered, degraded and fragmented as a result of intense urbanization and high-density housing developments along nearly the entire length of its very restricted range on the Bronberg Ridge. The extent of occurrence of this subpopulation has been fragmented into four sections by two major roads and a housing development. Quartzite mining operations pose an additional and severe threat of destroying the sole remaining primary east-west dispersal corridor inside the largest intact patch of remaining natural habitat (about 7.5 km x 0.9 km) (Jackson 2007, Jackson et al. 2007a). Such impacts may lead to genetic erosion (reduced genetic variability via inbreeding) and reduced population viability.
Inferred minor threats are predation by domestic pets, persecution by gardeners and land owners.
Enforcement of existing legislation and political will are urgently needed to conserve the Bronberg Ridge subpopulation. According to the Gauteng Ridge Policy (Pfab 2001), the Bronberg is a Class 2 ridge (5% - 35% have been transformed) and a no-go development policy is applicable, whereby only low impact developments will be considered, but then a full Environmental Impact Assessment (including public participation) is required. GDACEL (Gauteng Department of Agriculture, Conservation and Land Affairs) now GDARD (Gauteng Department of Agriculture and Rural Development) commissioned a Strategic Environmental Assessment to assist in formulating a policy to regulate development and activities in this area (See Pfab 2002). The sensitive nature of the Bronberg ecosystem as a whole was emphasized in the Gauteng Conservation Plan version 2 (C-Plan-2; Pfab 2006) and version 3 (C-Plan-3, Compaan 2011). The authors of this report, based at various departments at the University of Pretoria started researching certain aspects of the ecology and evolutionary relationships of Juliana’s Golden Mole (Neamblysomus julianae) in 2003. GDACE (Gauteng Department of Agriculture, Conservation and Environment) appointed and tasked a specialist research with compiling a conservation assessment of the Bronberg subpopulation of the species, based on ecological and molecular genetic findings that culminated in a conservation management plan, specifying actions to be implemented in an attempt to successfully conserve this critically endangered population (Jackson et al. 2007).
Despite all these actions, and a separate EIA tabled by EcoAssessments C.C. on behalf of local landowners, the Department of Mineral and Energy Affairs in 2003 re-issued a mining permit to allow mining to continue into the foreseeable future. In the last quarter of 2013, the Department of Mineral Resources (DMR) approved an intervention strategy for rehabilitation and stabilising of a slippage area in the quarry that will result in the loss of a substantial portion of the largest continuous sections of suitable habitat for the species remaining on the ridge, and destroy the primary east-west movement corridor in the process. Golden Mole specialist researchers confirmed the presence of and suitable habitat for the species and strongly advised against the planned intervention. Moreover, several residential and commercial developments have also been approved (last 5 - 7 years) in areas where clear signs of fresh activity and suitable habitat for the species were found. Local residents (Shere Residents Association) fiercely opposed the destruction of the Bronberg ecosystem and resident golden moles through legal action appeals via the NEMA process (National Environmental Management Authorities), yet these were all unsuccessful.
Sustained and concerted efforts, including legal interventions, are needed to ensure support GDARD in implementing their policies and to convince relevant provincial and national regulatory bodies of the dire threat faced by this population. Non-governmental conservation and legal organizations have now become involved in actions to oppose such developments.
Public education efforts should be sustained and expanded (especially among residents and local schools). Current research on systematics status of the Pretoria subpopulation should be expanded to incorporate conservation genetics data, and a thorough risk assessment should be done.
|Citation:||Maree, S. 2015. Neamblysomus julianae (Bronberg Ridge subpopulation). The IUCN Red List of Threatened Species 2015: e.T62010A21284251.Downloaded on 17 December 2017.|