The relationship between mammalian burrow abundance and bankrupt bush (Seriphium plumosum) encroachment




burrowing mammals, burrow density, Seriphium plumosum, Telperion Nature Reserve, Grassland Biome, shrub-density


Background: Much of the Grassland Biome in South Africa is prone to shrub encroachment, leading to loss of ecosystem services, habitat heterogeneity and species diversity. Burrowing mammals are an important component of grasslands as these animals create microhabitats for other taxa, including smaller mammal species, birds, reptiles and invertebrates. However, our understanding of how shrub encroachment affects burrowing mammals is poor.

Objectives: Here we assessed the relationship between burrow abundance and bankrupt bush, Seriphium plumosum, encroachment as well as burrowing mammal diversity in bankrupt bush encroached and non-encroached grasslands.

Method: Shrub density, medium and large mammal burrow abundance and density were measured in 24 encroached and 24 non-encroached areas randomly selected in the Telperion Nature Reserve, Mpumalanga, South Africa. In addition, burrowing mammal diversity was assessed using camera traps in a subset of six encroached and six non-encroached areas.

Results: Our results show that the abundance and density of medium and large burrows were significantly lower in encroached areas than in non-encroached areas (p = 0.011 and p < 0.001, respectively). The relationship between burrow abundance and bankrupt bush encroachment was negative (rho = -0.456, p = 0.001). However, burrowing mammal diversity had no significant difference between encroached and non-encroached areas.

Conclusion: Our data, therefore, suggest that with increasing bankrupt bush encroachment and a decreased abundance in burrowing mammal ecosystem services, a negative effect will occur on burrowing mammal communities, leading to the reduction in species-specific habitat heterogeneity and possibly animal biodiversity. 


Download data is not yet available.


Augustine, D., Manzon, A., Klopp, C. & Elter, J., 1995, ‘Habitat selection and group foraging of the springhare, Pedetes capensis, in East Africa’, African Journal of Ecology, 33, 347–357.

Avenant, P., 2015, ‘Report on the national bankrupt bush (Seriphium plumosum) survey (2010–2012)’, Department of Agriculture, Forestry & Fisheries, Directorate Land Use & Soil Management, Sub-directorate: Natural Resources Inventories & Assessments, South Africa.

Blaum, N., Rossmanith, E., Popp, A. & Jeltsch, F., 2007, ‘Shrub encroachment affects mammalian carnivore abundance and species richness in semiarid rangelands’, Acta Oecologica, 31, 86–92,

Buitenwerf, R., Bond, W., Stevens, N. & Trollope, W., 2011, ‘Increased tree densities in South African savannas: >50 years of data suggests CO2 as a driver’, Global Change Biology 18, 675–684,

Butynski, T.M. & Mattingly, R., 1979, ‘Burrow structure and fossorial ecology of the springhare Pedetes capensis in Botswana’, African Journal of Ecology, 17 205–215.

Carbutt, C., Tau, M., Stephens, A. & Escott, B., 2011, ‘The conservation status of temperate grasslands in southern Africa’, Grassroots 11, 17–23.

Davidson, A.D. & Lightfoot, D.C., 2008, ‘Burrowing rodents increase landscape heterogeneity in a desert grassland’, Journal of Arid Environments, 72, 1133–1145,

Davidson, A.D., Detling, J.K. & Brown, J.H., 2012, ‘Ecological roles and conservation challenges of social, burrowing, herbivorous mammals in the world’s grasslands’, Frontiers in Ecology and the Environment, 10, 477–486,

Eldridge, D.J.A. & Soliveres, S.B., 2014, ‘Are shrubs really a sign of declining ecosystem function? Disentangling the myths and truths of woody encroachment in Australia’, Australian Journal of Botany, 62, 594–608,

Elzinga, C.L., Salzer, D.W. & Willoughby, J.W., 1998, Monitoring Plant Populations, Bureau of Land Management, Denver, Colorado, USA.

Ewacha, M., Kaapehi, C., Waterman, J. & Roth, J., 2016, ‘Cape ground squirrels as ecosystem engineers: modifying habitat for plants, small mammals and beetles in Namib Desert grasslands’, African Journal of Ecology, 54, 68–75,

Fagir, D.M., Horak, I.G., Ueckermann, E.A., Bennett, N.C. & Lutermann, H., 2015, ‘Ectoparasite diversity in the eastern rock sengis (Elephantulus myurus): the effect of seasonality and host sex’, African Zoology, 50, 109–117,

Gabet, E.J., Reichman, O.J. & Seabloom, E.W., 2003, ‘The effects of bioturbation on soil processes and sediment transport’, Annual Review of Earth and Planetary Sciences, 31, 249–273.

Graham, S.C., Barrett, A.S. & Brown, L.R., 2020, ‘Impact of Seriphium plumosum densification on Mesic Highveld Grassland biodiversity in South Africa’, Royal Society Open Science 7, 192025,

Haussmann, N.S., 2017, ‘Soil movement by burrowing mammals: A review comparing excavation size and rate to body mass of excavators’, Progress in Physical Geography, 41, 29–45,

Herrick, J.E., Van Zee, J.W., Havstad, K.M., Burkett, L.M. & Whitford, W.G. (eds), 2005, Monitoring manual for grassland, shrubland and savanna ecosystems. Volume I: Quick Start. Volume II: Design, supplementary methods and interpretation, USDA-ARS Jornada Experimental Range, Las Cruces, USA.

Iribarren, C. & Kotler, B., 2012, ‘Foraging patterns of habitat use reveal landscape of fear of Nubian ibex Capra nubiana’, Wildlife Biology, 18, 194–201,

James, A.I., 2009, ‘Development of resource rich patches by soil disturbing animals in arid environments’, Ph.D. thesis, School of Biological, Earth and Environmental Sciences, University of New South Wales.

James, A. & Eldridge, D.J., 2007, ‘Reintroduction of fossorial native mammals and potential impacts on ecosystem processes in an Australian desert landscape’, Biological Conservation, 138, 351–359,

Jayadevan, A., Mukherjee, S. & Tamim, A.T., 2018, ‘Bush encroachment in fluences nocturnal rodent community and behaviour in a semi-arid grassland in Gujarat, India’, Journal of Arid Environments, 153, 32–38,

Jordaan, D., 2009, ‘Bankruptbush (slangbos) – A silent threat to grasslands?’, Grassroots, 9, 40–42.

Kgosikoma O.E., Harvie, B.A. & Mojeremane, W., 2012, ‘Bush encroachment in relation to rangeland management systems and environmental conditions in Kalahari ecosystem of Botswana’, African Journal of Agricultural Research, 7, 2312–2319,

Laundré, J. & Reynolds T., 1993, ‘Effects of soil structure on burrow characteristics of five small mammal species’, The Great Basin Naturalist, 53, 358–366.

Louw, M.A., Roux, P.C., Meyer-Milne, E. & Haussmann, N.S., 2017, ‘Mammal burrowing in discrete landscape patches further increases soil and vegetation heterogeneity in an arid environment’, Journal of Arid Environments, 141, 68–75,

Martin, S.A., 2017, ‘The aardvark as an ecological engineer in the Eastern Karoo: dig patterns and emergent processes’, M.Sc. thesis, Faculty of Science, Nelson Mandela Metropolitan University.

Martinez-Estevez, L., Balvanera, P., Pacheco, J. & Ceballos, G., 2013, ‘Prairie dog decline reduces the supply of ecosystem services and leads to desertification of semiarid grasslands’, PLoS ONE, 8, p.e75229,

Melton, D. & Daniels, C., 1986, ‘A note on the ecology of the aardvark Orycteropus afer’, South African Journal of Wildlife Research, 16, 4–6.

Meysman, F.J.R., Middelburg, J.J. & Heip, C.H.R., 2006, ‘Bioturbation: a fresh look at Darwin’ s last idea’, Trends in Ecology and Evolution, 21, 688–695,

Mucina, L. & Rutherford, M.C., 2006, The vegetation of South Africa, Lesotho and Swaziland, Strelitzia 19, South African National Biodiversity Institute, Pretoria.

Mueller-Dombois, D. & Ellenberg, H., 1974, Aims and methods of vegetation ecology, John Wiley and Sons, New York, USA.

Noble, J.C., Hik, D.S. & Sinclair, A.R.E., 2007, ‘Landscape ecology of the burrowing bettong: fire and marsupial biocontrol of shrubs in semi-arid Australia’, Rangeland Journal, 29, 107–119,

O’Connor, T., Puttick, J. & Hoffman, M., 2014, ‘Bush encroachment in southern Africa: changes and causes’, African Journal of Range & Forage Science, 31, 67–88,

Oksanen, J., Blanchet, F.G., Kindt, R., Legendre, P., Minchin, P.R., O’Hara, R.B., Simpson, G.L., Solymos, P., Stevens, M.H.H., Wagner, H. & Oksanen, M.J., 2013, Package ‘vegan’. Community ecology package, version, 2.

Rodgers, M., Bilton, M.C. & Hauptfleisch, M.L., 2017, ‘Responses and feedbacks of burrowing mammals under differently managed rangelands’, Namibian Journal of Environment, 1, 40–51.

Roux, E. 1969, Grass, a story of Frankenwald, Oxford University Press, Cape Town, pp. 153–159.

Skinner, J.D. & Chimimba C.T., 2005, Mammals of the southern African subregion, 3rd edition, Cambridge University Press, Cambridge, United Kingdom.

Snyman, H.A., 2012, ‘Habitat preferences of the encroacher shrub, Seriphium plumosum’, South African Journal of Botany, 81, 34–39,

Soto-Shoender, J.R., McCleery, R.A., Monadjem, A. & Gwinn, D.C., 2018, ‘The importance of grass cover for mammalian diversity and habitat associations in a bush encroached savanna’, Biological Conservation, 221, 127–136,

Stuart, C., 2015, Stuarts’ field guide to mammals of southern africa: including Angola, Zambia & Malawi, Penguin Random House, South Africa.

Uys, G., 2018, ‘Running a small hunting operation’, Farmer’s Weekly,13, 34–36.

Vahrmeijer, B.H., 2017, ‘Our unequal struggle with “problem” plants’, FarmBiz, December, 28–31.

Van Zyl, E. & Avenant, P., 2018, ‘Bankrupt bush: A serious threat to South Africa’s central grassland’, FarmBiz, February, pp. 40–42.

Ward, D., 2005. ‘Do we understand the causes of bush encroachment in African savannas?’, African Journal of Range & Forage Science, 22, 101–105,

Weltzin, J.F., Archer, S., & Heitschmidt, R.K., 1997, ‘Small-mammal regulation of vegetation structure in a temperate savanna’, Ecology, 78, 751–763.

Westfall, R. & Panagos, M., 1984, ‘A cover meter for canopy and basal cover estimations’, Bothalia, 15, 241–244.

Weyer, N.M., Fuller, A., Haw, A.J., Meyer, L.C.R., Mitchell, D., Picker, M., Rey, B. & Hetem, R.S., 2020, ‘Increased diurnal activity is indicative of energy deficit in a nocturnal mammal, the aardvark’, Frontiers in Physiology, 11, 637,

Whittington-Jones, G.M., 2006, ‘The role of aardvarks (Orycteropus afer) as ecosystem engineers in arid and semi-arid landscapes of South Africa’, M.Sc. thesis, Rhodes University.

Whittington-Jones, G.M., Bernard, R.T.F. & Parker, D.M., 2011, ‘Aardvark burrows: a potential resource for animals in arid and semi-arid environments’, African Zoology, 46, 362–370,


Williams, J.B. & Richardson, P.R.K., 1997, ‘Seasonal differences in field metabolism, water requirements, and foraging behavior of free-living aardwolves’, Ecology, 78, 2588–2602.




How to Cite

Oosthuysen, M., Strauss, W. M., & Somers, M. (2023). The relationship between mammalian burrow abundance and bankrupt bush (Seriphium plumosum) encroachment. Bothalia, African Biodiversity & Conservation, 53(1).



Original research, Reviews, Strategies, Case studies