1. Introduction 86

34 85 1. Introduction 86 69 30N 60 1.2.4 Biogeography87 88 93 65 95 98 96 92 97 94 111 99 62 61 35 100 101 115 36 25 70 2 39 83 102 37 38 59 71 1 4 3 4 6 7 5 10 40 44 116 9 103 104 31 12 11 13 16 0 73 41 8 18 14 45 15 17 66 20 47 72 27 43 48 46 42 19 118 112 10S 81 74 50 21 52 82 49 32 26 56 Figure S1.1 Terrestrial ecoregions in West and Central Africa (source: reproduced from Burgess et al. 75 2004). See Table S1.1 for legend. 106 51 119 33 55 64 53 67 63 84 A2 0detailedS description of the eight major biomes in the region with additional subdivisions based on76 29 the ecoregions follows. This description is based on information contained 5in8 WWF6 8& IUCN (1994), 30 Fishpool & Evans (2001), Burgess et al. (2004), and Happold & Lock (2013) and is supplemented57 by 114 other sources where appropriate. 107 54 Terrestrial ecoregions 105 109 113 Sahara Country boundary 22 77 78 The Sahara Desert extends across northern Mauritania, Mali, Niger and Chad. The topography11 7is 28 30S 79 varied and composed of gravel plains, sand dunes, rocky flats, wadis110 (dry watercourses), salt pans 108 23 and rare oases. Annual rainfall is 0–25 mm but very unpredictable and no rain at all may fall for many 0 250 500 1,000 1,500 2,000 2,500 80 years in any one locality. Temperatures can reach 50°C in the hottest months90 and fall below freezing 89 in the winter. The sparse vegetationKilomet econsistsrs of a few perennial grasses and herbs24 with91 sparse Acacia W E E E E 0 0 0 spp. in wadi beds. The desert grades southwards into desert steppe and then into the Sahel0 zone. 0 0 1 4 1 3 5 The Tibesti in northern Chad is a deeply dissected rocky massif with a highest point of 3,445 m. At higher elevations relict saharomontane vegetation occurs, with Olea laperrinei and other species. Wadis may have Acacia and Combretum trees. Lower mountains in the south also have incised wadis with permanent pools (gueltas) that contain relict crocodile populations. Figure 2.2 An IUCN situation analysis of terrestrial and freshwater fauna in West and Central Africa – Supplementary Information • 1 Table S1.1 Biomes and corresponding WWF ecoregions in West and Central Africa. The Aïr Mountains and Termit massif in Niger are situated on the edge of the Biome Ecoregions Number1 Sahara zone and contain some montane Sahara North Saharan steppe 93 flora elements. They also shelter important South Saharan steppe 94 remaining populations of Addax Addax Sahara desert 95 nasomaculatus, Dama Gazelle Nanger West Saharan montane xeric woodlands 96 dama and Cheetah Acinonyx jubatus Tibesti-Jebel Uweinat montane xeric woodlands 97 (e.g., Wacher et al. 2004a,b, 2010). The Sahel Sahelian Acacia savanna 35 Ennedi massif in Chad reaches 1,400 m Lake Chad flooded savanna 61 and higher elevations have a rare type of Inner Niger Delta flooded savanna 62 sahelomontane vegetation. Some wadis East Saharan montane xeric woodland 99 harbour a vegetation of Ficus salicifolia and Sudan-Guinea Savanna West Sudanian savanna 36 Olea laperrini, while rock pools have relict East Sudanian savanna 37 populations of crocodile. Guinean forest-savanna mosaic 38 Mandara Plateau mosaic 39 The larger desert ungulates and carnivores Jos Plateau Forest-Grassland Mosaic 83 have been largely extirpated or have Rainforest suffered massive declines as a result of Upper Guinea Forest Western Guinean lowland forests 1 overhunting (Beudels-Jamar et al. 2006, Guinean montane forests 2 Durant et al. 2012, 2014). Recent research Lower Guinea Forest Eastern Guinean forests 3 has shown that among the smaller Saharan Nigerian lowland forests 4 fauna, diversity is higher than earlier thought Niger Delta swamp forests 5 and several new and cryptic species are Cross-Niger transition forests 6 being described (Brito et al. 2013). Banc Cross-Sanaga-Bioko coastal forests 7 d’Arguin in northern Mauritania is a large Lowland Forest Central Congolian lowland forests 15 coastal wetland with great importance Northwestern Congolian lowland forests 12 for migrating and wintering Palearctic Northeastern Congolian lowland forests 16 waterbirds. Major protected areas include Coastal Forest Atlantic Equatorial coastal forests 8 Aïr and Tenéré (7,736 km2, of which 12,800 Swamp Forest Western Congolian swamp forests 13 core zone) and Termit Tin Toumma National Eastern Congolian swamp forests 14 Nature Reserve (97,000 km2) in Niger, and Rainforest-Savanna Northern Congolian forest-savanna mosaic 40 Banc d’Arguin NP and Biosphere Reserve Mosaic Southern Congolian forest-savanna mosaic 42 (1,200 km2) in Mauritania. Western Congolian forest-savanna mosaic 43 Afromontane Mt Cameroon & Bioko montane forests 9 Sahel Cameroon Highlands forests 10 Albertine Rift montane forests 17 The Sahel is a semiarid zone between the Rwenzori-Virunga montane moorlands 73 Sahara and West African savanna and Mangroves Guinean mangroves 115 running from Senegal through Mauritania, Central African mangroves 116 Mali, Burkina Faso, Niger and Chad. It Zambezian Woodland Central Zambezian Miombo woodlands 50 varies in width from several hundred to Angola Miombo Woodlands (just into SW DRC) 49 1,000 km and lies roughly between the 100 Zambezian Flooded Grasslands 63 mm and 600 mm isohyets (Zwarts et al. 1 Corresponding to Figure 2.1 2009). The Intertropical Convergence Zone (ITCZ) determines the quantity of rainfall in a particular year and where it falls. The Sahel was affected by severe droughts during the 1970s–1980s (‘la grande sécheresse’). The resulting desertification was originally thought to result from overgrazing and wood-cutting and soil erosion, but it was reversed with the return of the rains in the 1990s (Nicholson et al. 1998, Prince et al. 1998, Rasmussen et al. 2001). Habitats are a mixture of grassland and wooded grassland with wooded areas increasing to the south. Typical species include Acacia seyal, Acacia spp., and Boscia senegalensis and perennial grasses such as Panicum turgidum and Aristida sieberana. Human modification has been extensive through burning cutting and grazing and areas of natural habitat are almost all confined to protected areas. As with the Sahara, larger wildlife species have been eliminated or greatly depleted by hunting and competition for grazing and access to water with large herds of domestic livestock (Beudels-Jamar et al. 2006, Durant et al. 2012, 2014). 2 • An IUCN situation analysis of terrestrial and freshwater fauna in West and Central Africa – Supplementary Information Sahel wetlands provide important sites for birds migrating and wintering along the Afrotropical- Palaearctic flyway, as well as on intra-African migrations. The largest wetlands are Lake Chad and the Inner Niger Delta. Inner Niger Delta The Inner Niger Delta in central Mali consists of channels, swamps, and lakes and flooded grasslands extending over 425 km with an average width of 87 km. The area covered varies from ca. 3,900 km2 in the dry season to ca. 20,000 km2 during the rainy season (Zwarts et al. 2009). The delta harbours West African Manatees Trichechus senegalensis, although they are heavily hunted, Common Hippos Hippopotamus amphibius and crocodiles. There is a rich fish fauna of 110 different species. The Inner Niger Delta provides feeding, resting and wintering habitat for huge numbers of wetland birds, including Afrotropical resident species and migrants that spend the Palearctic winter in Africa. It also holds large waterfowl breeding colonies, with 80,000 pairs of 15 species (Denny 1991) and it is also a breeding stronghold for the West African subspecies of Black-crowned Crane Balearica pavonina pavonina (Meine & Archibald 1996). A notable non-wetland bird species is the endemic Mali Firefinch Lagonosticta virata. Lake Chad and Hadejia-Nguru wetlands Lake Chad is the largest lake in West and Central Africa and the fourth largest in Africa. It lies across the boundaries of Cameroon, Chad, Niger, and Nigeria. The lake currently covers 2,500 km2, about 10% of the area covered in the 1960s. A swamp belt divides the lake into a northern and southern basin which consists of islands (23%), reed beds (39%), and open water (38%). The area increases with flooding and the seasonally floodedyaeré grassands hold great importance for local pastoralists. The nearby Hadejia-Nguru wetlands in northern Nigeria cover about 6,000 km2, with a water surface area of 2,000 km2. These wetland complexes provide stopover, feeding and wintering habitat for over 1 million Palearctic waterbirds: Lake Chad also supports two near-endemic passerine bird species. West African manatees are also reported from the Baningi, Logone and Chari River tributaries of Lake Chad. A small part of the area is protected in Nigeria’s Chad Basin NP (2,258 km2). The Bodélé depression in the lake Chad Basin provides a global ecosystem service. Old lake bed sediments rich in iron and phosphorus are picked up by high winds and carried in plumes across the Atlantic, providing vital nutrients to the Amazon basin (Bristow et al. 2009, 2010). Protected areas in the Sahel zone include: Ferlo Nord (6,000 km2; Senegal), Ouadi Rimé-Ouadi Achim (77,950 km2; Chad), and Waza (1,700 km2; Cameroon). Sudan-Guinea Savanna The West African savanna zone runs from Senegal and Gambia to eastern Central African Republic and extends south in a narrow tongue through Benin and Togo to the coast of the Gulf of Guinea, forming the ‘Dahomey Gap’ between the Upper and Lower Guinea forest. Annual rainfall is in the range 600–1,000 mm. The terrain lies mainly between 200 and 400 m in elevation with the highest point just below 1,500 m.

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