Important Bird Areas in Africa and associated islands – Kenya ■ KENYA LEON BENNUN AND PETER NJOROGE Little Yellow Flycatcher Erythrocercus holochlorus. (ILLUSTRATION: NIK BORROW) GENERAL INTRODUCTION The region west of the central highlands is characterized by Precambrian metamorphic rocks. Mount Elgon (IBA KE059), an The Republic of Kenya (area 586,600 km2) lies astride the Equator old, eroded volcano, intrudes through the ancient shield on the on the eastern coast of Africa. It is bordered by Ethiopia and Uganda border. The Lake Victoria basin generally has a gently Sudan to the north, Uganda to the west, Tanzania to the south and sloping landscape and an eroded surface that exposes granitic the Indian Ocean and Somalia to the east. Inland water bodies outcrops. cover some 10,700 km2, the bulk of this in Lakes Victoria and Isolated hills and mountains, such as Mount Kulal, Mount Turkana. The coastline, about 550 km long, faces the Indian Nyiro and Mount Marsabit, are scattered to the north and east of Ocean. the central highlands. The Taita Hills (IBA KE021), rising from Kenya has tremendous topographical diversity, including the south-eastern plateau, are an ancient fault-block formation, glaciated mountains with snow-capped peaks, the Rift Valley with the northernmost of a chain of isolated peaks (the ‘eastern arc’) its scarps and volcanoes, ancient granitic mountains, flat desert that stretches south to Malawi through eastern and southern landscapes and coral reefs and islets. However, the basic Tanzania. They sit almost cheek-by-jowl with one of the region’s configuration is simple. Coastal plains give way to an inland plateau most recent volcanic ranges, the Chyulu Hills (KE026). that rises gradually to the central highlands, the result of relatively All Kenya’s major rivers drain from the central highlands, recent volcanic activity associated with the formation of the rift divided by the rift into those flowing westwards into Lake Victoria valley. To the west the land drops again to the Nyanza plateau that and those flowing eastwards towards the Indian Ocean. There are surrounds the Kenyan sector of Lake Victoria. five major drainage basins: Lake Victoria, the Rift Valley, the Athi- The coastline is broken and composed of beaches, coral cliffs Galana-Sabaki river (and coastal areas to its south), the Tana river and reefs, creeks and numerous offshore coral islands. Inland, a and the northern Ewaso Ngiro river. The Rift Valley contains mainly level but narrow coastal plain lies on sedimentary rocks, several basins of internal drainage, forming a chain of endorheic with some igneous intrusions such as Dzombo (IBA KE010) and lakes from Lake Natron on the Tanzanian border, through Lakes Mrima (KE018). Beyond low rolling hills lies the Nyika plateau, Magadi, Naivasha, Elmenteita, Nakuru, Bogoria, Baringo and mainly on sedimentary rocks. This is largely a thorn-bush plain Turkana (IBAs KE047, KE048, KE046, KE049, KE045, KE044 with seasonal drainage lines and a few isolated rocky hills. This and KE028 respectively). These lakes vary in alkalinity, from landscape covers almost the entire north-eastern sector of the freshwater Lake Naivasha to the intensely alkaline Lake Magadi. country, on a very gradually sloping plain. Lake Turkana is notable as a major volume of (more or less) fresh The Great Rift Valley, with its associated escarpments and water in an otherwise arid and barren part of the country, while a mountains, is a major feature. It runs the length of the country number of rivers, including the Turkwel, Kerio, Athi-Galana, Tana from Lake Turkana in the north to Lake Natron on the southern and Northern and Southern Ewaso Ngiro, flow for long distances border with Tanzania. The central portion of the rift is raised, with through dry parts of the country. Here they may often be the only the Aberdare mountains (IBA KE001) and Mount Kenya (KE005) permanent source of water. to the east and the Mau Escarpment (KE051 and KE052) and Kenya is generally a dry country; over 75% of its area is classed Cherangani Hills (KE043) to the west. The northern and as arid or semi-arid and only around 20% is viable for agriculture. southernmost sectors of the rift are low-lying, arid and rugged, Inland, rainfall and temperature are closely related to altitude with spectacular volcanic landforms. changes, with variations induced by local topography. Generally 411 Important Bird Areas in Africa and associated islands – Kenya Table 1. Summary of Important Bird Areas in Kenya. 60 IBAs covering c.54,330 km² Criteria (see p.11; for A2/A3 codes, see Tables 2/3) IBA A1 A2 A3 A4i A4ii A4iii code Site name Administrative region 105 108 109 111 s058 s061 A04 A05 A06 A07 A08 A09 KE001 Aberdare mountains Central ✔✔ ✔ KE002 Kianyaga valleys Central ✔✔ KE003 Kikuyu Escarpment forest Central, Rift Valley ✔✔ ✔ KE004 Kinangop grasslands Central, Rift Valley ✔✔ KE005 Mount Kenya Central, Eastern ✔✔ ✔ KE006 Mukurweini valleys Central ✔✔ KE007 Arabuko-Sokoke forest Coast ✔✔ ✔ KE008 Dakatcha woodland Coast ✔✔ ✔ KE009 Diani forest Coast ✔ KE010 Dzombo hill forest Coast ✔✔ KE011 Gede Ruins National Monument Coast ✔ KE012 Kaya Gandini Coast ✔✔ KE013 Kaya Waa Coast ✔ KE014 Kisite island Coast ✔ KE015 Kiunga Marine National Reserve Coast ✔ KE016 Mida Creek, Whale Island Coast ✔ and the Malindi–Watamu coast KE017 Marenji forest Coast ✔✔ ✔ KE018 Mrima hill forest Coast ✔ ✔ KE019 Sabaki river mouth Coast ✔ KE020 Shimba Hills Coast ✔✔ ✔ KE021 Taita Hills forests Coast ✔✔ KE022 Tana river delta Coast ✔ ✔✔ ✔ KE023 Tana river forests Coast ✔✔ ✔ KE024 Tsavo East National Park Coast, Eastern ✔ ✔ KE025 Tsavo West National Park Coast, Eastern ✔ ✔ KE026 Chyulu Hills forests Eastern, Rift Valley ✔✔ KE027 Dida Galgalu desert Eastern ✔✔✔ KE028 Lake Turkana Eastern, Rift Valley ✔✔ KE029 Machakos valleys Eastern ✔✔ KE030 Masinga reservoir Eastern ✔✔ KE031 Meru National Park Eastern ✔✔ ✔ KE032 Mwea National Reserve Eastern ✔✔ KE033 Samburu and Buffalo Springs National Reserves Eastern, Rift Valley ✔ KE034 Shaba National Reserve Eastern ✔✔✔ KE035 Dandora ponds Nairobi ✔ KE036 Nairobi National Park Nairobi ✔✔ ✔ KE037 Dunga swamp Nyanza ✔✔ KE038 Koguta swamp Nyanza ✔✔ KE039 Kusa swamp Nyanza ✔✔ KE040 Ruma National Park Nyanza ✔ KE041 Yala swamp complex Nyanza, Western ✔✔ KE042 Amboseli National Park Rift Valley ✔ KE043 Cherangani Hills Rift Valley ✔ KE044 Lake Baringo Rift Valley ✔ KE045 Lake Bogoria National Reserve Rift Valley ✔ ✔✔ KE046 Lake Elmenteita Rift Valley ✔✔✔ ✔✔ KE047 Lake Magadi Rift Valley ✔✔ KE048 Lake Naivasha Rift Valley ✔✔ ✔✔ KE049 Lake Nakuru National Park Rift Valley ✔✔ ✔✔ KE050 Masai Mara Rift Valley ✔✔✔ KE051 Mau forest complex Rift Valley ✔ KE052 Mau Narok–Molo grasslands Rift Valley ✔✔ KE053 North Nandi forest Rift Valley ✔✔✔ KE054 Ol Donyo Sabache Rift Valley ✔ KE055 South Nandi forest Rift Valley ✔✔ KE056 South Nguruman Rift Valley ✔✔✔ KE057 Busia grasslands Western ✔✔ KE058 Kakamega forest Western ✔✔✔ KE059 Mount Elgon Western, Rift Valley ✔✔ ✔✔ KE060 Sio Port swamp Western ✔✔ Total number of IBAs qualifying: 47 1 5 16 7 2 22356871318 412 Important Bird Areas in Africa and associated islands – Kenya Map 1. Location and size of Important Bird Areas in Kenya. SUDAN Area of IBA (ha) LAKE ETHIOPIA TURKANA > 1,000,000 28 100,000 to 999,999 50,000 to 99,999 27 10,000 to 49,999 1,000 to 9,999 100 to 999 UGANDA <100 43 Area undefined 59 54 44 34 53 45 33 60 57 SOMALIA 58 31 41 55 5 37 49 46 1 51 6 LAKE 38 2 VICTORIA 39 40 52 4 48 30 32 3 35 50 36 56 15 47 29 23 26 42 22 24 TANZANIA 25 8 INDIAN OCEAN 19 21 7 11 16 12 0 250 500 20 13 10 9 km 18 17 14 the climate is warm and humid at the coast and in the Lake Victoria the Aberdare mountains (KE001), the Cheranganis (KE043) and basin, cool and humid in the central highlands, and hot and dry in Mount Elgon (KE059). Highland grassland (0.05%), often with the north and east. Across most of the country, rainfall is strongly tussocks, is present above c.2,400 m on either side of the central seasonal, although its pattern, timing and extent vary greatly from Rift Valley (in the Kinangop and Mau Narok–Molo grasslands, place to place and from year to year. KE004 and KE052). Other important grassland types include fire- Except for the coast and the Lake Victoria region, altitude is induced grassland (3.1%, e.g. parts of the Masai Mara, KE050) the main determinant of precipitation. The high-altitude areas (over and seasonal flood-plain and delta grassland (4.7%, e.g. the Tana c.1,500 m) in the central Kenya highlands usually have substantial river delta, KE022). Grassland also occurs on alkaline volcanic rainfall, reaching over 2,000 mm per year in parts of the Mau ash (0.2%), for example to the south of the Chyulu Hills (KE026). Escarpment. However, topography also has a major influence, with Highland moist forest (2.0%) occurs between c.1,500 m and 3,000 strong rain-shadow effects east of Mount Kenya and the Aberdare m in areas that receive more than 1,200 mm of rain per year. At mountains. The highlands are thus surrounded by a set of semi- higher levels this is often a mosaic of forest and bamboo. Relicts of arid upland plateaus. To the north, the Laikipia plateau receives Guineo-Congolian rainforest (0.1%) persist in western Kenya, in 400–800 mm of rain in indeterminate seasons. To the south, rainfall and around Kakamega forest (IBA KE058). The North and South varies from 400–600 mm on the dry rift floor to as much as Nandi forests (KE053 and KE055) are transitional between the 1,000 mm in the Loita Hills, with varying seasonality. In the arid Guineo-Congolian and montane forest types. Several types of coastal lowlands, rainfall averages less than 500 mm and varies greatly from forest and woodland (0.1%), characteristic of the Zanzibar- year to year.