Overview

Suncus lixus – (Thomas, 1898)

ANIMALIA – CHORDATA – MAMMALIA – EULIPOTYPHLA – SORICIDAE – Suncus – lixus 

Common Names: Greater Dwarf Shrew (English), Groter Dwergskeerbek (Afrikaans)

Synonyms: No Synonyms 

Taxonomic Note:
Suncus lixus possibly represents a complex of at least two similar species within the assessment region. Additionally, Meester and Lambrechts (1971) and Meester et al. (1986) recognised two subspecies: S. l. lixus from Zimbabwe and Botswana and S. l. gratulus from within the assessment region. Further studies are needed to clarify the taxonomic status of populations currently allocated to this species. 

Red List Status: LC – Least Concern, (IUCN version 3.1) 

Assessment Information

Assessor: Russo, I.M.¹ & da Silva, J.M.²

Reviewer: Smith, C³. & Patel, T.³

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

Previous Assessors: Taylor, P., Baxter, R. & Monadjem, A. 

Previous Reviewer: Child, M.F. 

Previous Contributors: Avenant, N., Avery, M., Wilson, B., Palmer, G. & MacFadyen, D. 

Assessment Rationale 

The Greater Dwarf Shrew is widespread in the assessment region, occurring in a variety of habitats, including suburban gardens, and thus can tolerate slightly transformed landscapes. It occurs in a number of protected areas and can be locally common in suitable habitats, such as riverine woodland, sandveld and moist grasslands. There is no evidence to suggest a net population decline. Therefore, we keep this species listed as Least Concern. However, we caution that molecular data, coupled with further field surveys to delimit distribution more accurately, are needed to determine whether the highveld and subtropical grassland subpopulations comprise separate species. If so, both species will need to be reassessed as high rates of grassland habitat loss in both regions may qualify one or both species for a threatened status. 

Key interventions include protected area expansion of moist grassland and riverine woodland habitats, as well as providing incentives for landowners to sustain natural vegetation around wetlands and keep livestock or wildlife at ecological carrying capacity to avoid overgrazing. 

Regional population effects: There is a disjunct distribution between populations in the assessment region and the rest of its range. This species is also a poor disperser. Thus, there is no significant rescue effect between the populations in the assessment region and its neighbouring range. 

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: Russo IM & da Silva JM. 2025. A conservation assessment of Suncus lixus. 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 

Throughout the global range of the Greater Dwarf Shrew there are only a few scattered records (Skinner & Chimimba 2005). However, it is a widespread species that ranges through East Africa, Central Africa and southern Africa. Within the assessment region, it occurs in Mpumalanga, Limpopo, North-West and KwaZulu-Natal provinces. It also occurs in Malolotja and Mlawula Nature Reserves in Eswatini (formerly Swaziland; Monadjem 1998). The known range of the species has been extended westwards into the Zeerust area of the North West Province through recent field surveys (Power 2014). 

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 Greater Dwarf Shrew (Suncus lixus) 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

Climate change is considered to be the principal emerging threat to this species, both due to loss of habitat and habitat degradation from drying out of wetlands and because shrews cannot tolerate extremes of temperature for long and thus their foraging time will be reduced. Because of their high metabolism, low dispersal capacity and short life spans, climate change may reduce the amount of suitable habitat available. 

Population

It can be locally common in suitable habitat and is regularly caught during field surveys. For example, it was regularly sampled recently at both Mkhuze Game Reserve and Phinda Private Game Reserve in the KwaZulu-Natal Province in a variety of habitat types (Rautenbach et al. 2014; Delcros et al. 2015). Considering it is rare in museum collections (P. Taylor pers. comm.), these are important findings. 

Population Information 

Current population trend: Unknown  

Number of mature individuals in population: Unknown  

Number of mature individuals in largest subpopulation: Unknown  

Number of subpopulations: Unknown  

Severely fragmented: No. Can utilise modified habitats, but poor dispersal ability may negate its broad habitat suitability. 

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

Continuing decline in number of subpopulations: (Not specified) 

All individuals in one subpopulation: (Not specified) 

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

While numerous molecular studies have been undertaken on other Suncus species, particularly within Asia, no population genetic studies have been conducted on this species within the assessment region. Given the limited records and studies for this species it is not possible to estimate the number of isolated subpopulations or their effective population size (Ne). 

Habitats and ecology

This species has generally been recorded from dry savannah and dry woodland habitats. It has also been encountered in riverine forest, open dry scrub, open grassland, coastal lowland forest, Acacia woodland and suburban gardens (Rautenbach 1982; Wirminghaus & Nanni 1989; Baker & Meester 1991; Taylor 1998). It has been recorded from bushveld in the Rustenberg area of the North West Province (Power 2014). In Mkhuze Game Reserve and Phinda Private Game Reserve in KwaZulu-Natal Province, they were recently found to be most common in riverine woodland and floodplain grassland respectively (Rautenbach et al. 2014; Delcros et al. 2015). They have been collected from highveld sour grassland in Eswatini (Monadjem 1998). 

Ecosystem and cultural services: An important prey species. They are insectivorous and have been recorded in Barn Owl pellets (Skinner & Chimimba 2005). 

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: (Not specified) 

Size at Maturity (in cms): Male: (Not specified) 

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) 

Does the species lay eggs? (Not specified) 

Does the species give birth to live young: (Not specified) 

Does the species exhibit parthenogenesis: (Not specified) 

Does the species have a free-living larval stage? (Not specified) 

Does the species require water for breeding? (Not specified) 

Movement Patterns 

Movement Patterns: (Not specified) 

Congregatory: (Not specified) 

Systems 

System: Terrestrial 

General Use and Trade Information

There is no known subsistence or commercial use of this species. 

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 main threat to shrews is the loss or degradation of moist, productive areas such as wetlands and rank grasslands within suitable habitat. The two main drivers behind this are abstraction of surface water and draining of wetlands through industrial and residential expansion, and overgrazing of moist grasslands, which leads to the loss of ground cover and decreases small mammal diversity and abundance (Bowland & Perrin 1989, 1993). Suppression of natural ecosystem processes, such as severe or too frequent fire, can also lead to habitat degradation through bush encroachment or loss of plant diversity through alien invasives, and is suspected to be increasing with human settlement expansion. There are also clear overlaps and synergistic effects between these threats. Across South Africa, 65% of wetland ecosystem types are threatened (48% of all wetland types are Critically Endangered, 12% are Endangered and 5% are Vulnerable; Driver et al. 2012). 

Current habitat trend: In KwaZulu-Natal Province alone, there was a 19.7% loss of natural habitat from 1994 to 2008, with an average loss of 1.2% per annum (Jewitt et al. 2015). If this rate of loss continues into the future, there will be an estimated 12% loss of habitat over 10 years. Additionally, between 2000 and 2013, there has been a 5.6% and 1.1% rate of urban and rural expansion in KwaZulu-Natal Province respectively (GeoTerraImage 2015). However, as long as natural vegetation is maintained around wetlands, rivers and artificial waterbodies, habitat for this species is suspected to remain stable. 

Conservation

Greater Dwarf Shrews are present in several protected areas (including the Kruger National Park) across its range within the assessment region. The main intervention for this species is the protection and restoration of wetlands and grasslands. Biodiversity stewardship schemes should be promoted if landowners possess wetlands or grasslands close to core protected areas or remaining habitat patches, and the effects on small mammal subpopulations should be monitored. Protecting such habitats may create dispersal corridors between habitat patches. At the local scale, landowners and managers should be educated, encouraged and incentivised to conserve the habitats on which shrews and small mammals depend. Retaining ground cover is the most important management tool to increase small mammal diversity and abundance. This can be achieved through lowering grazing pressure (Bowland & Perrin 1989), or by maintaining a buffer strip of natural vegetation around wetlands (Driver et al. 2012). Small mammal diversity and abundance is also higher in more complex or heterogeneous landscapes, where periodic burning is an important tool to achieve this (Bowland & Perrin 1993). Removing alien vegetation from watersheds, watercourses and wetlands is also an important intervention to improve flow and water quality, and thus habitat quality for shrews. Education and awareness campaigns should be employed to teach landowners and local communities about the importance of conserving wetlands and moist grasslands. 

Recommendations for land managers and practitioners: 

• Landowners and communities should be incentivised to stock livestock or wildlife at ecological carrying capacity to avoid overgrazing and to maintain a buffer of natural vegetation around wetlands. 

Research priorities: 

• Molecular research is needed to ascertain the validity of the putative species complex. 

• Additional field surveys are needed to clarify and confirm the distribution of this species. 

Encouraged citizen actions: 

• Citizens are requested to submit any shrews killed by cats or drowned in pools to a museum or a provincial conservation authority for identification, thereby enhancing our knowledge of shrew distribution (carcasses can be placed in a ziplock bag and frozen with the locality recorded). 

Bibliography

Baker, C.M. and Meester, J.A.J. 1991. A new record of the greater dwarf shrew (Suncus lixus) from Natal. Durban Museum Novitates 16: 36. 

Bowland, A.E. and Perrin, M.R. 1989. The effect of overgrazing on the small mammals in Umfolozi Game Reserve. Zeitschrift für Säugetierkunde 54: 251–260. 

Bowland, J.M. and Perrin, M.E. 1993. Wetlands as reservoirs of small-mammal populations in the Natal Drakensberg. South African Journal of Wildlife Research 23: 39–43. 

Delcros, G., Taylor, P.J., and Schoeman, M.C. 2015. Ecological correlates of small mammal assemblage structure at different spatial scales in the savannah biome of South Africa. Mammalia 79(1): 1-14. 

Driver, A., Sink, K.J., Nel, J.N., Holness, S., Van Niekerk, L., Daniels, F., Jonas, Z., Majiedt, P.A., Harris, L. and Maze, K. 2012. National Biodiversity Assessment 2011: An assessment of South Africa’s biodiversity and ecosystems. Synthesis Report. South African National Biodiversity Institute and Department of Environmental Affairs, Pretoria, South Africa. 

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

Jewitt, D., Goodman, P.S., Erasmus, B.F.N., O’Connor, T.G. and Witkowski, E.T.F. 2015. Systematic land-cover change in KwaZulu-Natal, South Africa: Implications for biodiversity. South African Journal of Science 111: 1-9. 

Meester J, von Lambrechts AW. 1971. The southern African species of Suncus Ehrenberg (Mammalia: Soricidae). Annals of the Transvaal Museum 27: 1-14. 

Meester, J.A.J., Rautenbach, I.L., Dippenaar, N.J. and Baker, C.M. 1986. Classification of Southern African Mammals. Monograph number 5. Transvaal Museum , Pretoria, South Africa. 

Monadjem A. 1998. The mammals of Swaziland. Conservation Trust of Swaziland and Big Games Parks, Mbabane, Swaziland. 

Power, R.J. 2014. The distribution and status of mammals in the North West Province. Department of Economic Development, Environment, Conservation & Tourism, North West Provincial Government, Mahikeng. 

Rautenbach A, Dickerson T, Schoeman MC. 2014. Diversity of rodent and shrew assemblages in different vegetation types of the savannah biome in South Africa: no evidence for nested subsets or competition. African Journal of Ecology 52: 30-40. 

Rautenbach, I. L. 1982. Mammals of the Transvaal. Ecoplan monograph, N.S. Supplemento 1: 111-211. 

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

Taylor, P. 1998. The Smaller Mammals of KwaZulu-Natal. University of Natal Press, Pietermaritzburg, South Africa. 

Wirminghaus JO, Nanni RF. 1989. Some additional Suncus lixus records for Natal. Lammergeyer 40: 4-5.