Overview

Amblysomus robustus – Bronner, 2000

ANIMALIA – CHORDATA – MAMMALIA – AFROSORICIDA – CHRYSOCHLORIDAE – Amblysomus – robustus 

Common Names: Robust Golden Mole (English), Robuster Goldmull (German)
Synonyms: No Synonyms 

Taxonomic Note: 
Previously included in A. hottentotus; elevated to a full species by Bronner (2000) based on unique karyotype, robust build and subtle craniometric differences from A. hottentotus and A. septentrionalis. There are some distinctive anatomical features of A. robustus, such as the reduced posterior cusp on its second lower molar (i2) vs. a more prominent posterior cusp on the i2 of A. h. hottentotus (Bronner et al. 2024:character #100), and a sacrum incorporating more fused vertebrae (Bronner et al. 2024: characters #115-116). However, recent phylogenetic analyses revealed that A. hottentotus represents a species complex, encompassing both A. robustus and A. septentrionalis (Mynhardt et al. 2015, 2020). Further research is needed to determine whether A. robustus and A. septentrionalis should retain full species status. 

Red List Status: VU – Vulnerable, B1ab(iii) (IUCN version 3.1)  

Assessment Information

Assessors: Mynhardt, S.¹ & da Silva, J.² 

Reviewer: Patel, T.¹ 

Contributor: Asher, R.³ 

Institutions: ¹Endangered Wildlife Trust, ²South African National Biodiversity Institute, ³University of Cambridge 

Previous Assessor: Rampartab, C. 

Previous Reviewers: Bronner, G. & Taylor, A. 

Assessment Rationale 

The species is listed Vulnerable because the extent of occurrence is estimated to be 12,584 km², with continuing decline and possible severe fragmentation of habitat. Currently known from only five locations but probably more widespread than suggested by the sparse distribution records available (Bronner 2000, 2013). The Highveld grasslands favoured by this species are being degraded by mining for shallow coal deposits to fuel numerous power stations that occur in the preferred high-altitude grassland habitats of this species, which is an inferred major threat. Rehabilitation attempts at these sites have proved largely ineffective. These power stations form the backbone of South Africa’s electricity network, and disturbance is likely to increase as human populations grow and the demand for power increases. While no mining sites and power generation plants occur at the five localities where this species has been collected, an environmental authorisation application to mine coal at a site near Belfast, close to where this species occurs, is currently being assessed. Given the ubiquity of mines and power stations in the Mpumalanga grasslands, impacts on this species are likely if it is more widespread than current records indicate, which seems probable. Farming, tourism resort developments and agro-forestry (exotic pine and eucalyptus plantations) have also transformed habitat, but less dramatically; these do not appear to pose a major threat. More data are required on distribution limits, ecology, densities and reproduction. 

Reasons for Change 

Reason(s) for Change in Red List Category from the Previous Assessment: No change 

Red List Index 

Red List Index: No change 

Recommended citation: Mynhardt S & da Silva JM. 2025. A conservation assessment of Amblysomus robustus. In Patel T, Smith C, Roxburgh L, da Silva JM & Raimondo D, editors. The Red List of Mammals of South Africa, Eswatini and Lesotho. South African National Biodiversity Institute and Endangered Wildlife Trust, South Africa.

Regional Distribution and occurrence

Geographic Range 

The species is endemic to South Africa. Known only from the Steenkampsberg mountains in the Belfast and Dullstroom districts of eastern Mpumalanga, extending eastwards to Lydenberg and possibly southwards towards the Ermelo district where A. septentrionalis instead occurs. Currently known from only a few locations but probably more widespread than suggested by the sparse distribution records available (Bronner 2000, 2013). For example, based on mitochondrial DNA markers, this species may occur in Ngome Forest (KwaZulu-Natal), as well as Mariepskop (but could also pertain to A. h. meesteri) and Malelane (but could also pertain to A. septentrionalis) in Mpumalanga (Mynhardt et al. 2015); all three records require further validation through additional specimen collecting and gene sequencing. Distribution modelling similarly predicts that this species ranges northeastwards from confirmed localities to Mariepskop and Sabie (Rampartab 2016). The area of occupancy for this species is 96 km² (based on the IUCN method of a 2 by 2 km grid). 

Number of locations: 5 

Continuing decline in number of locations: No 

Elevation / Depth / Depth Zones 

Elevation Lower Limit (in metres above sea level): (Not specified) 

Elevation Upper Limit (in metres above sea level): (Not specified) 

Depth Lower Limit (in metres below sea level): (Not specified) 

Depth Upper Limit (in metres below sea level): (Not specified) 

Depth Zone: (Not specified) 

MAP

Figure 1. Distribution records for Robust Golden Mole (Amblysomus robustus) within the assessment region (South Africa, Eswatini and Lesotho). Note that distribution data is obtained from multiple sources and records have not all been individually verified.

Biogeographic Realms 

Biogeographic Realm: Afrotropical 

Occurrence 

Countries of Occurrence 

Large Marine Ecosystems (LME) Occurrence 

Large Marine Ecosystems: (Not specified) 

FAO Area Occurrence 

FAO Marine Areas: (Not specified) 

Climate change

Although the potential impacts of climate change on this species have not been directly assessed, climate change is expected to impact most golden mole species. Since these subterranean animals are restricted to soft soils for burrowing, and have very low vagility, their ability to migrate or shift their distribution ranges in response to climate change is very limited. Climate change is likely to impact golden moles through changes in vegetation type, soil moisture and prey availability. 

Population information

Common in suitable natural habitats, also in gardens, orchards and cultivated lands; no quantitative data are available on population sizes or trends.  

Current population trend: Unknown 

Continuing decline in mature individuals? (Not specified) 

Extreme fluctuations in the number of subpopulations: (Not specified) 

Continuing decline in number of subpopulations: (Not specified) 

All individuals in one subpopulation: No 

Number of mature individuals in largest subpopulation: (Not specified) 

Number of Subpopulations: (Not specified) 

Severely fragmented: No 

Quantitative Analysis 

Probability of extinction in the wild within 3 generations or 10 years, whichever is longer, maximum 100 years: (Not specified) 

Probability of extinction in the wild within 5 generations or 20 years, whichever is longer, maximum 100 years: (Not specified) 

Probability of extinction in the wild within 100 years: (Not specified) 

Population genetics

This species has been investigated in a phylogenetic context (e.g., Mynhardt et al. 2015, 2020), and interestingly insufficient divergence was detected between A. robustus and A. septentrionalis (Mynhardt et al. 2015), possibly suggesting they represent genetically distinct subpopulations of the same species or possibly ESUs (given differences in karotype [chromosome number]; Bronner 2009) or have only recently speciated. Currently the species remain separate. Consequently, A. robustus is comprised of one population. Given the lack of census or effective population size (Ne) data, the genetic health of the population cannot be inferred.  

Habitats and ecology

This species occurs within montane grasslands and marshes in Moist Sandy Highveld Grassland in eastern Mpumalanga, South Africa. They prefer friable soils, from sands to quite heavy clays, but avoid shallow substrates along rocky ridges (which may act as dispersal barriers) and waterlogged areas. Although it can survive in gardens and farmyards (Bronner 2013), its core grassland habitats are being lost to mining activities in the region. 

IUCN Habitats Classification Scheme 

Life History 

Generation Length: (Not specified) 

Age at Maturity: Female or unspecified: (Not specified) 

Age at Maturity: Male: (Not specified) 

Size at Maturity (in cms): Female: 11-14

Size at Maturity (in cms): Male: 12-14 

Longevity: (Not specified) 

Average Reproductive Age: (Not specified) 

Maximum Size (in cms): (Not specified) 

Size at Birth (in cms): (Not specified) 

Gestation Time: (Not specified) 

Reproductive Periodicity: (Not specified) 

Average Annual Fecundity or Litter Size: (Not specified) 

Natural Mortality: (Not specified) 

Breeding Strategy 

Does the species lay eggs?  No 

Does the species give birth to live young? Yes

Does the species exhibit parthenogenesis? No

Does the species have a free-living larval stage? No

Does the species require water for breeding? No

Movement Patterns 

Movement Patterns: (Not specified) 

Congregatory: (Not specified) 

Systems 

System: Terrestrial 

General Use and Trade Information

General notes regarding trade and use of this species: This species is not known to be utilised or traded in any form. 

Local Livelihood: (Not specified) 

National Commercial Value: (Not specified) 

International Commercial Value: (Not specified) 

End Use: (Not specified) 

Is there harvest from captive/cultivated sources of this species? (Not specified) 

Harvest Trend Comments: (Not specified)

Threats

The Highveld grasslands favoured by this species have been, and continue to be, altered and degraded by mining of shallow coal deposits to fuel numerous power stations in the region. Although these activities are not currently occurring at the five known localities, an environmental authorisation application to mine coal in the Belfast area, where this species occurs, is currently being assessed. Given the ubiquity of mines and power stations in the Mpumalanga grasslands, this species is likely to be impacted if it is more widespread than current records indicate. 

Agricultural activities, the development of numerous tourism resorts, and agroforestry have, and continue, to transform the habitat of this species, but it appears to survive (perhaps at lower densities) in such disturbed areas, suggesting that the nature and intensity of this alterations does not yet pose a major threat. Otherwise, predation by domestic pets, and persecution by gardeners in urban areas, likely represent more localized threats. 

Continuing decline in area, extent and/or quality of habitat: Yes. Decreasing in area and quality. The Mpumalanga Tourism and Parks Agency (MTPA) mapped all development applications received at a cadastral scale over a 14-year period (2000–2014), which showed that greatest pressure for land-use change has come from prospecting applications (54.2% of the land surface area of Mpumalanga) and mining (24.5% of land surface area), together accounting for 61.3% of the surface area of the province, and can anticipate much greater expansion in the mining sector than ever before (Lötter et al. 2014). Additionally, there has been a 7.2% and 10.5% increase in rural and urban settlements in Mpumalanga between 2000 and 2013 (GeoTerraImage 2015).

Conservation

Amblysomus robustus has been recorded from the provincial Verloren-Vallei Nature Reserve in Mpumalanga. Research is currently underway to accurately determine the distribution limits of this species, and to confirm its distinctness from A. hottentotus and A. septentrionalis using molecular data. Further research is required to document its basic ecology and reproductive parameters. This species would benefit from protected area expansion and land management practices that reduce overgrazing and degradation. 

Recommendations for land managers and practitioners: 

• Field surveys to discover additional subpopulations. 
• Incentivise landowners to de-stock to reduce overgrazing impacts and to stop cattle grazing in vleiland refugia during winter. 

Research priorities: 

• Field studies to determine life history traits and ecological tolerances of this species. 
• Studies on population size, trends and distribution. 
• Determine the severity of threats, specifically quantifying the impact from mining activities. 

Encouraged citizen actions: 

• Report sightings on virtual museum platforms (for example, iNaturalist and MammalMAP), especially outside protected areas. 
• Deposit any dead specimens found in a state or provincial museum, together with information on the date and site where found. 
• Create native vegetation gardens. 

Bibliography

Afrotheria Specialist Group. 2014. Specialist Group website. Available at: http://www.afrotheria.net/index.php.  

Bronner, G.N. 1996. Geographic patterns of morphometric variation in the Hottentot golden mole, Amblysomus hottentotus (Insectivora: Chrysochloridae): a multivariate analysis. Mammalia 60: 729–751. 

Bronner, G.N. 2009. New species and subspecies of golden mole (Chrysochloridae: Amblysomus) from Mpumalanga, South Africa. Mammalia 64: 41–54. 

Bronner, G.N. 2013. Amblysomus robustus. In: J. Kingdon, D. Happold, T. Butynski, M. Hoffmann, M. Happold and J. Kalina (eds), Mammals of Africa, Volume I: Introductory Chapters and Afrotheria, pp. 231-232. Bloomsbury Publishing, London. 

Bronner, G.N. and Jenkins, P.D. 2005. Order Afrosoricida. In: D.E. Wilson and D.M. Reeder (eds), Mammal Species of the World, pp. 70-81. The Johns Hopkins University Press, Baltimore, MD, USA. 

Bronner, GN., Mynhardt, S., Bennett, NC., Cohen, L., Crumpton, N., Hofreiter, M., Arnold, P. & Asher, RJ. 2024. Phylogenetic History of Golden Moles and Tenrecs (Mammalia, Afrotheria). Zoological Journal of the Linnean Society 201(1):184-213.  

GeoTerraImage. 2015. Quantifying settlement and built-up land use change in South Africa. Pretoria.  

IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015.2. Available at: www.iucnredlist.org. (Accessed: 23 June 2015). 

Lötter, M.C., Cadman, M.J. and Lechmere-Oertel, R.G. 2014. Mpumalanga Biodiversity Sector Plan Handbook. MTPA. Nelspruit. 

Mynhardt, S., Bennett, N.C. and Bloomer, P., 2020. New insights from RADseq data on differentiation in the Hottentot golden mole species complex from South Africa. Molecular phylogenetics and evolution, 143, p.106667.  

Mynhardt, S., Maree, S., Pelser, I., Bennett, N.C., Bronner, G.N., Wilson, J.W. and Bloomer, P., 2015. Phylogeography of a morphologically cryptic golden mole assemblage from South-Eastern Africa. PLoS One, 10(12), p.e0144995.   

Rampartab, C. 2016. Facilitating golden mole conservation in South African highland grasslands: a predictive modelling approach. University of Cape Town. 

Skinner, J.D. and Chimimba, C.T. (eds). 2005. The Mammals of the Southern African Subregion. Third edition. Cambridge University Press, United Kingdom, Cambridge.