Short Communication Subterranean herpetofauna show a decline after 34 years in Ndumu Game Reserve, South Africa G.J ohn M easey ,A drian J.A rmstrong and C atharin E ´ H anekom Abstract Subterranean herpetofauna comprise an estimated 20% of the world’s amphibians and reptiles but are one of the least studied groups of terrestrial vertebrates. Monitoring population trends and threats to these species is dependent in part on quantitative historical data, which are generally lacking. One exception is a 1970 study conducted in Ndumu Game Reserve, South Africa. We revisited this area in 2004 and carried out comparative quantitative sampling in de- ciduous broad-leaf woodland and sand forest habitats. Our results show a 79% reduction in density of subterranean herpetofauna, as well as a reduction in diversity. Mann- Whitney tests show that the amphisbaenian Zygaspis van- dami has undergone a significant reduction in density in both habitats sampled. We relate reductions in subterranean herpetofaunal densities to an increased density of the Reserve’s ungulate grazers, suggesting a link between reduction in leaf-litter and soil macrofauna prey of the fossorial reptiles. This study highlights the need for quantitative surveys of subterranean herpetofauna to support future conservation efforts. Keywords Amphisbaenian, reptile, Scelotes bidigittatus, South Africa, subterranean, ungulate, Zygaspis vandami. E cological studies of soil flora and fauna are widely recognized as having lagged behind those of their terres- trial counterparts. Subterranean herpetofauna (amphibians and reptiles) inhabit many areas of the globe and occur on every continent except Antarctica. In general they are elon- gate, have reduced or absent limbs and heads modified for burrowing. All are predators of soil macrofauna, especially earthworms, termites and ants (e.g. Webb et al., 2000). Until recently, knowledge of these diverse herpetofaunal groups has come from anecdotal observations in taxonomic treatise. There are two major challenges to monitoring changes in vertebrate species below ground. Firstly, they are cryptic and difficult to sample and, secondly, little historical data exist with which to compare density estimates obtained. The first of these problems has been addressed to a limited ex- tent by the proposal of a number of quantitative and semi- quantitative sampling techniques (Measey, 2006). The second is more problematic as virtually no historical data exist and few baseline data are being published. The vulnerability of subterranean vertebrates has seldom been recognized. Where known, many species appear to be well adapted to cohabitation with small-scale human agri- culture (Hebrard et al., 1992; Measey, 2006) but suspected threats come from above ground processes either directly (e.g. soil compaction, which exponentially increases the force required for burrowing; Navas et al., 2004), or in- directly by affecting potential food items (e.g. the impact of pesticides on abundance of soil macrofauna). The relation- ship between leaf-litter quantity and soil macrofauna has been well studied (Ponsard et al., 2000; Negrete-Yankelevich et al., 2007). Within protected areas, changes in stocking of keystone herbivores can have profound effects on vegetation (Sinclair, 2003) and, by inference, on soil macrofauna. To our knowledge the only published study detailing his- torical quantitative abundance of subterranean herpetofauna was conducted in Ndumu Game Reserve, South Africa, dur- ing March and April 1970 (Pooley et al., 1973). Two habitat types were sampled within the Reserve, yielding a total of eight species and with high densities of Van Dam’s round- headed worm lizard Zygaspis vandami and the lowveld dwarf burrowing skink Scelotes bidigittatus. Here we report an investigation of the current densities of subterranean herpetofauna in Ndumu Game Reserve and compare herbi- vore stocking levels and leaf-litter accumulation at the same two sites visited by Pooley et al. (1973). We summarize the results of Pooley et al. (1973) and compare them to our own, highlighting significant differences between the data sets as well as suggesting possible causal links. Ndumu Game Reserve forms part of the north-eastern boundary of KwaZulu-Natal and therefore South Africa with Mozambique (Fig. 1). Sites visited by Pooley et al. (1973) and resampled in this study are Ndumu Hill and uluKhondo Forest, corresponding to Pooley et al.’s (1973) type A and B areas, respectively. The vegetation on Ndumu Hill is predominantly deciduous broad-leaf woodland on Hutton soils with grass-dominated ground cover; the vege- tation of the uluKhondo Forest is classified as sand forest on Fernwood soils with a sparse understorey characterized by forbs and bushes together with numerous mounds of fungus-growing termites (Termitidae: Macrotermitinae: G. JOHN MEASEY (Corresponding author) Applied Biodiversity Research, Kirstenbosch Research Centre, South African National Biodiversity Institute, Private Bag X7, Claremont 7735, South Africa, and Department of Bio- diversity and Conservation Biology, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa. E-mail john@measey.com ADRIAN J. ARMSTRONG and CATHARINE ´ HANEKOM Ezemvelo KZN Wildlife, KwaZulu-Natal, South Africa. Received 20 December 2007. Revision requested 13 February 2008. Accepted 7 April 2008. ª 2009 Fauna & Flora International, Oryx, 43(2), 284–287 doi:10.1017/S0030605307002311 Printed in the United Kingdom https://doi.org/10.1017/S0030605307002311 Published online by Cambridge University Press