Impact of poaching on the population structure and insect associates of the Endangered Encephalartos eugene-maraisii from South Africa


  • Paul Duvel Janse van Rensburg North-West University
  • Hugo Bezuidenhout
  • Johnnie van den Berg



cycads, conservation areas, herbivore-plant interactions, population decline, impact


Background: South Africa is an important centre of cycad diversity in Africa, however, the country’s cycads face extinction. Among the primary causes is the poaching of plants from the wild, even within protected areas.

Objectives: This study examined poaching patterns in a local population of the Endangered Encephalartos eugene-maraisii I.Verd. and how it might affect the population structure, sex ratios, as well as interactions with associated insects.

Methods: The population was surveyed in 2008 and 40% of this population was resurveyed between 2021 and 2022. We mapped missing cycads and generated heatmaps. Lastly, we investigated whether the proportion of stems from different size classes, sex ratios and abundance of insect associates varied between areas with a high and low poaching incidence.

Results: Poaching, defined as the illegal removal of individuals from the wild, occurred 1.5 times more frequently along the border fence line than areas further away. Medium-sized stems (21–80 cm) are primarily targeted (likely as they can be carried more easily) and low proportions of these stems remain in areas with a high poaching incidence. While E. eugene-maraisii exhibits some resilience against poaching through basal suckering, it takes several decades for suckers to mature and replace harvested stems. No effect on sex ratios were recorded in areas with a high poaching incidence, suggesting poachers have not deliberately selected female or male cycads at this site. No pollinating insects were detected on E. eugene-maraisii, and no seedlings were observed.

Conclusion: Cone production may be too rare in diminished populations to support pollinators that utilise cones as brood sites. The presence of insects that use other plant parts, including leaves, dried leaf stalks and cycad trunks, in the larger population suggests that they are more resilient to diminishing host populations. However, these insects were absent in smaller populations, and their abundances were lower in low-density sites and smaller clump sizes of their host in the larger population. This suggests these insects may be vulnerable to the decline of their host populations due to poaching.


Download data is not yet available.


Bamigboye, S.O. & Tshisikhawe, M.P., 2020, ‘The impacts of bark harvesting on a population of Encephalartos transvenosus (Limpopo cycad), in Limpopo Province, South Africa’, Biodiversitas 21, 8–13,

Bezuidenhout, H., 2019, ‘Supplementation of the Encephalartos eugene-maraisii populations in Marakele National Park’, Internal report 02/2019, Scientific Services, Kimberley, SANParks.

Bezuidenhout, H., Steyn, T., Van Staden, W., Hofmeyr, M. & Froneman, W., 2017, ‘Monitoring the cycad population in Marakele National Park’, Internal report 27/2017, Scientific Services, Kimberley, SANParks.

Bezuidenhout, H., Steyn, T., Mamatsharaga, T., Froneman, W., Rodgers, S., Lessing J., Van den Berg, J. & Van Eeden, W., 2020, ‘Management plan for the Encephalartos eugene-maraisii (Waterberg cycad)’, Internal report 08/2020, Scientific Services, Kimberley, SANParks.

Botha, J., Witkowski, E.T.F. & Shackleton, C.M., 2004a, ‘Harvesting impacts on commonly used medicinal tree species (Catha edulis and Rapanea melanophloeos) under different land management regimes in the Mpumalanga Lowveld, South Africa’, Koedoe 47(2),

Botha, J., Witkowski, E.T.F. & Shackleton, C.M., 2004b, ‘The impact of commercial harvesting on Warburgia salutaris (‘pepper-bark tree’) in Mpumalanga, South Africa’, Biodiversity and Conservation 13, 1675–1698,

Cabrera-Toledo, D., González-Astorga, J., Vovides, A.P., Casa, A., Vargas-Ponce, O., Carrillo-Reyes, P., Nolasco-Soto, J. & Vega, E., 2019, ‘Surviving background extinction: inferences from historic and current dynamics in the contrasting population structures of two endemic Mexican cycads’, Population Ecology 61, 62–73,

Calonje, M., Stevenson, D.W. & Osborne, R, 2023, ‘The world list of cycads, online edition’,, date accessed: 7 July 2023.

Chiyo, P.I., Obanda, V. & Korir, D.K., 2015, ‘Illegal tusk harvest and the decline of the tusk size in the African Elephant’, Ecology and Evolution 5, 5216–5229,

Colling, G. & Matthies, D., 2004, ‘The effects of plant population size on the interactions between the endangered plant Scorzonera humilis, a specialised herbivore, and a phytophagous fungus’, Oikos 105, 71–78,

Courchamp, F., Angulo, E., Rivalan, P., Hall, R.J., Signoret, L., Bull, L. & Meinard, Y., 2006, ‘Rarity value and species extinction: the anthropogenic Allee effect’, PLoS Biology 4, 2405–2410,

Cousins, S.R., Williams, V.L. & Witkowski, E.T.F., 2011, ‘Quantifying the trade in cycads (Encephalartos species) in the traditional medicine markets of Johannesburg and Durban, South Africa’, Economic Botany 65, 356–370,

Cousins, S.R., Williams, V.L. & Witkowski, E.T.F., 2012, ‘Uncovering the cycad taxa (Encephalartos species) traded for traditional medicine in Johannesburg and Durban, South Africa’, South African Journal of Botany 78l, 129–138,

Cousins, S.R., Williams, V.L. & Witkowski, E.T.F., 2013, ‘Sifting through cycads: a guide to identifying the stem fragments of six South African medicinal Encephalartos species’, South African Journal of Botany 84, 115–123,

De Klerk, G.J., 2008, ‘Report on the census of Waterberg cycad on the Entabeni Safari Conservancy’, An internal report by Envirodel, Polokwane for Entabeni Safari Conservancy.

Donaldson, J.S., 2003, ‘Regional overview: Africa’, in J.S. Donaldson (ed.), Cycads, status survey and conservation action plan, pp. 9–19, IUCN/SSC Cycad Specialist Group: Gland, Switzerland and Cambridge, UK.

Donaldson, J.S., 2008, ‘South African Encephalartos species’, NDF workshop case studies: Case Study 4: Encephalartos, Mexico.

Government Gazette, 2017, ‘Biodiversity management plan for 11 Critically Endangered and 4 Endangered Encephalartos species (Notice 315 of 2017)’, Government Gazette 40815, 28 April 2017.

Griffiths, A.D., Schult, H.J. & Gorman, J., 2005, ‘Wild harvest of Cycas arnhemica (Cycadaceae): impact on survival, recruitment and growth in Arnhem Land, northern Australia’, Australian Journal of Botany 53,771–779,

IBM Corp., 2021, ‘IBM SPSS statistics for windows, version 28.0’, Armonk, NY: IBM Corp.

IUCN, 2023, ‘The IUCN Red List of threatened species’,, viewed 21 January 2023.

Janse van Rensburg, P.D., Bezuidenhout, H. & Van den Berg, J., 2023, ‘Impact of herbivory by Zerenopsis lepida (Lepidoptera: Geometridae) on the Endangered Encephalartos eugene-maraisii under field conditions’, Biodiversity and Conservation 32, 2451–2468,

Kéry, M., Matthies, D. & Fischer, M., 2001, ‘The effect of plant population size on the interactions between the rare plant Gentiana cruciate and its specialized herbivore Maculinea rebeli’, Journal of Ecology 89, 418–427,

Krishnamurthy, V., Mandle, L., Ticktin, T., Ganesan, R., Saneesh, C.S. & Varghese, A., 2013, ‘Conservation status and effects of harvest on an endemic multi-purpose cycad, Cycas circinalis L., Western Ghats, India’, Tropical Ecology 54, 309–320.

Marler, T.E. & Calonje, M., 2020, ‘Two cycad species affect the carbon, nitrogen and phosphorus contents of soil’, Horticulture 6, 24,

Marler, T.E., Griffith, M.P. & Krishnapillai, M.V., 2020, ‘Height increment of Cycas micronesica informs conservation decisions’, Plant Signaling and Behavior 15: e1830237,

Mucina, L., Hoare, D.B., Lötter, M.C., et al., 2006, ‘Grassland Biome’, in L. Mucina & M.C. Rutherford (eds), The vegetation of South Africa, Lesotho and Swaziland, Strelitizia 19, 349–437, South African National Biodiversity Institute, Pretoria.

Ndou, T.M., Stam, E.M., Tshisikhawe, M.P., Alabi, M.A. & Adeeyo, A.O., 2021, ‘Poaching of Encephalartos transvenosus, in the Limpopo Province, South Africa’, Resources 10, 119,

Oberprieler, R.G., 1995, ‘The weevils (Coleoptera: Curculionoidea) associated with cycads. 2. Host specificity and implications for cycad taxonomy’, in P. Vorster (ed.), Proceedings of the Third international Conference on Cycad Biology, pp. 335–365, Cycad Society of South Africa: Stellenbosch, South Africa.

Oberprieler, R.G., 1999, ‘Systematics and evolution of the cycad-associated weevil genus Apinotropis Jordan (Coleoptera: Anthribidae)’, African Entomology 7, 1–33,

Okubamichael, D.Y., Jack, S., Bösenberg, J.D., Hoffmann, M.T. & Donaldson, J.S., 2016, ‘Repeat photography confirms alarming decline in South African cycads’, Biodiversity Conservation 25, 2153–2170,

Osborne, R., 1995, ‘The world cycad census and a proposed revision of the threatened species status for cycad taxa’, Biological Conservation 71, 1–12,

Raimondo, D.C. & Donaldson, J.S., 2003, ‘Responses of cycads with different life histories to the impact of plant collecting: simulation models to determine important life history stages and population recovery times’, Biological Conservation 111, 345–358,

Ravele, A.M. & Makhado, R.A., 2010, ‘Exploitation of Encephalartos transvenosus outside and inside Mphaphuli Cycads Nature Reserve, Limpopo Province, South Africa’, African Journal of Ecology 48, 105–110,

Steyn, T. & Bezuidenhout, H., 2020, ‘Entabeni biodiversity and conservation value’, Internal report for Entabeni Safari Conservancy, Scientific Services, Kimberley, South African National Parks.

Thomas, C.D. & Jones, T.M., 1993, ‘Partial recovery of a skipper butterfly (Hesperia comma) from population refuges: lessons for conservation in a fragmented landscape’, Journal of Animal Ecology 62, 472–481,

Toon, A., Terry, L.I., Tang, W., Walter, G.H. & Cook, L.G., 2020, ‘Insect pollination of cycads’, Austral Ecology 45, 1033–1058,

Torgersen, J.S., 2017, ‘Crime, culture and collecting: the illicit cycad market in South Africa’, Unpublished MSc dissertation, University of Cape Town, South Africa.

Vovides, A.P., 1990, ‘Spatial distribution, survival, and fecundity of Dioon edule (Zamiaceae) in a tropical deciduous forest in Veracruz, Mexico, with notes on its habitat’, American Journal of Botany 77, 1532–1543,

Williamson, J., Maurin, O., Shiba, S.N.S., Van der Bank, H., Pfab, M., Pilusa, M., Kabongo, R.M. & Van der Bank, M., 2016, ‘Exposing the illegal trade in cycad species (Cycadophyta: Encephalartos) at two traditional medicine markets in South Africa using DNA barcoding’, Genome 59, 771–781,




How to Cite

Janse van Rensburg, P. D., Bezuidenhout, H., & van den Berg, J. (2023). Impact of poaching on the population structure and insect associates of the Endangered Encephalartos eugene-maraisii from South Africa. Bothalia, African Biodiversity & Conservation, 53(1).



Original research, Reviews, Strategies, Case studies