Mammals in Gola Forest, Sierra Leone J Eremy A
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CORE Metadata, citation and similar papers at core.ac.uk Provided by Wageningen University & Research Publications The impact of civil war on forest wildlife in West Africa: mammals in Gola Forest, Sierra Leone J eremy A. Lindsell,Erik K lop and A lhaji M. Siaka Abstract Human conflicts may sometimes benefit wildlife et al., 1996). However, the generality of this argument has by depopulating wilderness areas but there is evidence been challenged and recent evidence, especially from forest- from Africa that the impacts tend to be negative. The based conflicts in Africa, suggests a negative impact from forested states of West Africa have experienced much over-harvesting of wildlife, degradation of habitats and recent human conflict but there have been no assessments pollution, and the prevention of a range of necessary of impacts on the wildlife. We conducted surveys of conservation and protection activities (Dudley et al., mammals in the 710-km2 Gola Forest reserves to assess 2002; McNeely, 2003). Understanding the effects of conflict the impact of the 1991–2001 civil war in Sierra Leone. Gola on wildlife has important implications for the way conser- is the most important remaining tract of lowland forest in vation agencies work in conflict areas (Plumptre et al., the country and a key site for the conservation of the 2000; Hanson et al., 2009), especially how effectively they highly threatened forests of the Upper Guinea region. We can respond at the cessation of hostilities (Draulans & Van found that Gola has survived well despite being in the Krunkelsven, 2002; McNeely, 2003) because the period of heart of the area occupied by the rebels. We recorded 44 time immediately after war is often crucial (Dudley et al., species of larger mammal, including 18 threatened, near- 2002). threatened and endemic species, accounting for all species Areas of high biodiversity appear to be particularly recorded in pre-war surveys and adding several more vulnerable to conflict (Hanson et al., 2009). The Upper (African buffalo Syncerus caffer nanus and water chevro- Guinea forests of West Africa (between Guinea and Togo) tain Hyemoschus aquaticus). Populations of primates were are in a region where three of the six forested countries healthy with little evidence of decline. Duiker detection have recently suffered armed conflict and unrest. These rates were low and further work is required to confirm forests are of high global biological importance because their numbers as they include five species endemic (or near they form one of the two main blocks of African tropical endemic) to the Upper Guinea region, three of which are forest, with high levels of biodiversity and endemism and threatened. However, the population of African forest numerous threatened species (Stattersfield et al., 1998; elephants Loxodonta cyclotis has collapsed, with only a Poorter et al., 2004). These forests are considered a critical 2 few individuals remaining from c. 110 in the mid 1980s. priority for conservation because only c. 5,000 km of We conclude that peacetime pressures from the bushmeat pristine forest remains of a former total area of c. 50,000 2 trade, clearance for agriculture, logging and mining are km (Mittermeier et al., 2004). They are threatened by likely to be far greater for Gola than the pressures from the logging for timber, clearance for agriculture and mining, civil war. and hunting for the bushmeat trade (Brashares et al., 2004). The impacts of war may exacerbate any or all of these Keywords Cercopithecus, distance, Gola forest, Hexaproto- pressures; however, there have been few studies that have don liberiensis, Loxodonta cyclotis, Sierra Leone, tropical documented such impacts. forest, war Gola Forest in Sierra Leone, at the west of the Upper Guinea block, provides an opportunity to assess the impacts of war. It is the last remaining extensive tract of Introduction lowland forest in Sierra Leone and one of the most important remaining forests in the region (Davies, 1987; reas of human conflict may be important for wildlife Collar & Stuart, 1988; Allport et al., 1989; Fishpool & Evans, because the exclusion of normal economic activities in A 2001; Okoni-Williams et al., 2005) holding most of the such areas can result de facto in conservation (Martin & region’s endemic, threatened and near-threatened mam- Szuter, 1999) and create effective protected areas (Higuchi mals and birds (Davies, 1987; Klop et al., 2008). Forest featured significantly in the 1991–2001 civil war in Sierra Leone (Richards, 2005) and the Revolutionary United Front JEREMY A. LINDSELL (Corresponding author) and ERIK KLOP Royal Society for the Protection of Birds, The Lodge, Sandy, Bedfordshire, SG19 2DL, UK (RUF) established a number of camps in forested areas, E-mail [email protected] including near Gola Forest. The RUF’s reliance on forest is 1995 ALHAJI M. SIAKA Gola Forest Programme, Kenema, Sierra Leone made clear in their manifesto (Sankoh, ), leading 2001 Received 4 November 2009. Revision requested 25 January 2010. Squires ( ) to conclude that there must have been Accepted 9 March 2010. a significant negative impact on forest biodiversity. Gola ª 2011 Fauna & Flora International, Oryx, 45(1), 69–77 doi:10.1017/S0030605310000347 70 J. A. Lindsell et al. Forest was the subject of a number of biological surveys Methods prior to the war (Merz, 1986; Davies, 1987; Allport et al., 1989; Davies et al., 2007) and thus resurveys to assess Our post-war surveys were based on line transect distance 2001 changes during the intervening period may be valuable. We sampling (Buckland et al., ). Lines transects are consid- undertook biodiversity surveys in Gola Forest in 2006–2007 ered the most efficient way to sample wildlife in African 2000 to determine the effects of the war on the forest (Klop et al., forests (Plumptre, ) although for certain groups such as 2008) and report here how the results from the mammal nocturnal duikers other methods may be preferable (Davies 2007 surveys compare with pre-war data, providing the first et al., ). Transects were randomly superimposed onto assessment of change in a West African forest during the study area in a systematic segmented grid sampling 2004 a period of war. design (Buckland et al., ), stratified by forest block area to account for variation in habitat quality among the blocks. Study area Transect fragments at the reserves’ boundaries were dis- counted for logistical reasons. Forty-eight transects were Gola Forest in Sierra Leone lies along the border with surveyed, 28 twice, totalling 245.3 km of survey effort: 23.8 km Liberia between 7°189 and 7°519 N and 10°379 and 11°219 W. in Gola West, 72.0 km in Gola East, 129.3 km in Gola North It is dominated by lowland moist evergreen high forest, and 20.2 km in Extension 2. All transects were surveyed on with an annual rainfall of c. 3,000 mm mostly falling in foot by two observers between December 2005 and April a single wet season from May to October. The woody 2007. All encounters were recorded, including signs (e.g. vegetation is dominated by Leguminosae–Caesalpinoideae, dung, footprints, nests), and the position along the transect Euphorbiaceae, Leguminosae–Mimosoideae and Sterculia- was noted to the nearest 25 m. Distances to sightings were ceae (Klop et al., 2008). Three forest reserves were gazetted measured using a laser rangefinder (accuracy – 1 m) and from the 1930s onwards, consisting of four forest blocks bearings were recorded with a compass. 2 2 (Fig. 1). Gola West (c. 67 km ) and Gola East (c. 205 km ) Encounter rates per km were calculated from visual and are low-lying and swampy (mean altitudes of 131 and 152 m, aural records. Primate group densities were calculated from 2 respectively). Gola North (c. 417 km ) and its Extension 2 group sightings only, using Distance v. 5.0 (Thomas et al., 2 (c. 61 km ) are more rugged and higher than the surround- 2010). Perpendicular distances were left ungrouped and the ing landscape (mean altitude 303 m). The forest is drained upper 5% of distances truncated. Primate observations were by the Moa River to the west and the Mano and Moru pooled for analysis and post-stratified by species. Popula- rivers to the east. Tiwai Island is a low-lying sandy island tion densities were estimated by multiplying group densi- 2 (mean altitude 120 m) of c. 12 km in the Moa River, close to ties by mean group size. Estimates of group size based on Gola West. It has been the subject of intensive biological single sightings of unhabituated primate groups may be research in the past (Oates et al., 1990) and we consider it inaccurate (Thomas, 1991) and line transect counts can briefly here. underestimate group size (Defler & Pintor, 1985; Thomas, 11°20'W 11°10'W 11°W 10°50'W 10°40'W 7°50'N EXTENSION 2 Moa RUF camp Mogbai 7°40'N hoi (approx) NORTH Ma TIWAI ISLAND 7°30'N Moro Guinea WEST no Sierra Leone Ma FIG. 1 The Gola Forest reserves (shaded) EAST and Tiwai Island, with main rivers and the km national border with Liberia. Inset shows 7°20'N 0510 Liberia the location of the main map in West Africa. ª 2011 Fauna & Flora International, Oryx, 45(1), 69–77 Mammals in Gola Forest 71 1991). Mean group sizes from Tiwai Island (Oates et al., 1990) western red colobus Piliocolobus badius were high but the were therefore also used. These were based on intensively species was not ubiquitous (44% of transects), preferring studied groups, and previous estimates of primate abun- the less disturbed areas of Gola North (Fig. 3) where the dance on Tiwai Island (Fimbel, 1994) and in Gola Forest encounter rate was .