Herpetology Notes, volume 14: 1051-1065 (2021) (published online on 09 August 2021) Amphibians and reptiles of a proposed iron ore mining concession in southern Cameroon Nono L. Gonwouo1,*, Arnaud M.F. Tchassem1, Thomas M. Doherty-Bone2,3, and Mark-Oliver Rödel4 Abstract. We present a checklist of amphibian and reptile species that occur in the Ntem Iron ore mining concession in southern Cameroon, compiled as part of a broader biodiversity impact survey during a two-week herpetofaunal survey. Visual and acoustic encounter surveys were carried out during day and night, covering the entire area of mining exploration. We document the presence of 38 amphibian and 28 reptile species. The most notable observation was a 150-km southward range extension of Didynamipus sjostedti. Other species of conservation concern include Conraua goliath, Leptodactylodon albiventris, L. ventrimarmoratus, Osteolaemus tetraspis, Varanus niloticus, and Kinixys erosa. These and numerous other forest-dwelling species indicate the intact nature of herpetofauna forest assemblages at the study sites. Efforts to conserve the herpetofauna at these sites should focus on protecting and monitoring the intact forest corridors linking the concession to a neighbouring forest reserve, as well as plans for restoration once extraction is completed. Keywords. Species richness, habitat, fragmentation, management, rainforest Introduction influenced by microclimate, such as temperature and humidity, as well as by the presence of microhabitats (e.g., Anthropogenic habitat change is a major factor driving forest leaf litter; Wake, 1991; Blaustein et al., 1994; Ernst species and population declines (Stuart et al., 2004; et al., 2006), making them vulnerable to forest alteration Reading et al., 2010; Böhm et al., 2013; Pimm et al., and clearance (Ernst and Rödel, 2005; Ernst et al., 2006; 2014), and it has been identified as a primary threat to Barrett and Guyer, 2008). Many investigations provide 85% of species classified as threatened in the IUCN Red strong support for differences in species composition List (IUCN, 2015). Among vertebrates, amphibians and among human-modified landscapes (e.g., Thompson and reptiles are considered the groups most impacted by Donnelly, 2018) and, as such, management practices that various anthropogenic land use changes (Gibbons et al., alter habitat characteristics may have long-term effects 2000; Stuart et al., 2004; Barrett and Guyer, 2008; Böhm on amphibian and reptile community composition. et al., 2013; Nori et al., 2015). Habitat disturbance and Mining is one form of land use change that imposes degradation are known to impose positive and negative primary and secondary impacts on biodiversity, starting effects on herpetofauna, species richness, abundance and from exploration, through extraction and infrastructure composition (Lea et al., 2003; Adum et al., 2013; Guerra establishment, to restoration (Rödel and Bangoura, 2004). and Ar’aoz, 2015; Thompson et al., 2016). Herpetofauna As in most other parts of western Africa, deforestation in general, but amphibians in particular, are strongly rates in Cameroon are high (Mayaux et al., 2004; Hansen et al., 2013; Mallon et al., 2015). Cameroon is subject to severe forest degradation, fragmentation, and other forest 1 Laboratory of Zoology, Faculty of Sciences, University of area loss, mainly due to growing small to large-scale Yaoundé I, PO Box 812, Yaoundé, Cameroon. agricultural development and timber exploitation. This 2 Conservation Programmes, The Royal Zoological Society of habitat loss is cause for concern for biodiversity in the Scotland, Edinburgh Zoo, 134 Corstorphine Road, Edinburgh region, with mining exploration a further emerging form EH12 6TS, Scotland, United Kingdom. of land use change that could affect amphibian and reptile 3 Department of Life Sciences, The Natural History Museum, diversity in the region. Several studies have reported Cromwell Road, London SW7 5BD, United Kingdom. mining to significantly impact herpetofauna worldwide 4 Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, (Hillers et al., 2008; Sasaki, 2015; Mayani-Parás et al., Germany. 2019), but there have been few reports from Africa, * Corresponding author. E-mail: [email protected] despite a rapidly growing number of mining projects on © 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0. the continent (see Rödel et al., 2021). 1052 Nono L. Gonwouo et al. Despite the growing number of mining projects in to the sea to the concession. The area around the planned Cameroon, many forest biomes within the country mine site is characterised by a heterogeneous topography remain undersurveyed yet are subject to changing land with steep hills and small- to medium-sized streams. use (Mallon et al., 2015). As Cameroon’s topography The primary evergreen tropical rainforest appears to be is highly heterogeneous, biodiversity is often range- intact, with relatively little or no alteration. Localities restricted, increasing the probability that unsurveyed sites along the proposed railway appeared more degraded, could hold undocumented herpetofauna of conservation composed mostly of secondary forest, farmbush, as well concern. Indeed, new species continue to be described as oil palm and rubber plantations. Old logging roads (e.g., Lötters and Schmitz, 2004; Blackburn, 2008; were discernible within the secondary forest, still being Blackburn et al., 2009; Rödel et al., 2012; Gvoždik et utilised for access into forest for subsistence agriculture al., 2020) and clearly support this assumption. and medium-scale oil palm plantations. Further west An iron ore mining exploitation project is being planned along the proposed railway line, extensive agro-industrial at Ntem, a lowland rainforest locality near Akom II, plantations (rubber and palm oil) have been established. South Region of Cameroon. It was imperative that the Natural resource use takes place throughout the study herpetofauna of the proposed concession be assessed area, including hunting, collection of non-timber forest to help formulate measures to effectively mitigate the products, and wood extraction for local use. Artisanal impact of the planned mining on the biodiversity. Apart gold mining is practiced in some villages in the area. from a 0.5° x 0.5° range nationwide survey on reptiles The ethnic group of Bagili/Bakola (pygmies) inhabits the that covered this study site (Chirio and LeBreton, 2007), forest, with several camps found within the concession. no herpetological investigation has been undertaken Data collection. The survey was spread over 77 in the area so far. Hence, a herpetological survey was sampling sites, including 36 sites around the planned conducted in the Ntem concession and associated sites. mine concession and 41 sites along the proposed railway Our objectives were to develop an amphibian and corridor (Fig. 1). Visual and acoustic amphibian and reptile species inventory and obtain data on habitat reptile surveys were undertaken by three surveyors during use and preferences within the proposed concession. day and night (Heyer et al., 1993; Rödel and Ernst, 2004). This information is critical to planning site-specific Surveys consisted of walking through a selected habitat management needs and development of an effective type while recording observations of active amphibians land management strategy within the region. and reptiles. We tried to spend more time in complex (i.e., dense vegetation) as opposed to uniform habitats to Materials and Methods account for visual bias in the observed encounter rates of species in different habitat types. Study site. The Ntem concession project area is Survey techniques included searching microhabitats by situated 40 km north of Akom II, along the road to lifting rocks and logs, peeling away bark, moving fallen Bipindi in the Ocean Division, South Region, Cameroon. debris, and inspecting tree trunks. A headlamp was used It covers a surface area of about 3.17 km2 in the locality to look into cracks and holes in logs and rocks. When of Anyouzok and extends between 2.9206−2.9383°N encountered, most animals were collected by hand and latitude and 10.4150−10.4281°E longitude (Fig. 1). This some aquatic amphibians by the use of dip-nets (5 x 6 project site will be linked by a railway line (to deliver cm square, 40 cm long). Specimens were identified in iron ore for exportation) of about 80 km to the shore the field and immediately released at the point of capture. around Eboundja I, south of the main town of Kribi. Specimens of uncertain identification were placed in Surveys were carried out from 5–18 December 2014 (a plastic bags and identified later using identification keys total of 12 days) prior to the exploration phase. Since (Chirio and LeBreton, 2007; Trape et al., 2012) or original then, activities around the site have been suspended descriptions and derived literature (Perret, 1966; Amiet, and the area has remained unmined. Early December 1977, 1980; Schiøtz, 1999). Unidentifiable specimens represents the early dry season, at time with relatively were euthanised using a chlorobutanol solution and, after low rainfall. Given its location close to the coast, average tissue extraction, fixed in 10% buffered formaldehyde annual rainfall is 2263 mm with a temperature mean and preserved in 75% ethanol. Voucher specimens have of about 25°C (Gonmadje et al., 2012). The area falls been deposited in the herpetological collection of