Population and distribution of Wattled Cranes and other large waterbirds on the Kafue Flats, Zambia

WORKING PAPER # 1

ZAMBIA CRANE AND WETLAND CONSERVATION PROJECT

Bernard Kamweneshe Richard Beilfuss

Zambia Crane and Wetland Conservation Project February 2002

International Crane Foundation

WORKING PAPERS OF THE ZAMBIA CRANE AND WETLAND CONSERVATION PROJECT

1. Population and distribution of Wattled Cranes and other large waterbirds on the Kafue Flats,

Zambia (Kamweneshe and Beilfuss 2002) 2. Population and distribution of Kafue lechwe and other large mammals on the Kafue flats,

Zambia (Kamweneshe, Beilfuss, and Simukonda 2002) 3. Wattled Cranes, waterbirds, and large mammals of the Lukanga Swamp, Zambia

(Kamweneshe and Beilfuss 2002) 4. Wattled Cranes, waterbirds, and large mammals of the Liuwa Plain National Park, Zambia

(Kamweneshe, Beilfuss, and Morrison in prep) 5. Wattled Cranes, Shoebills, and other large waterbirds of the Bangweulu Swamps, Zambia

(Kamweneshe, Beilfuss, McCann, and Zyambo in prep)

2

ACKNOWLEDGEMENTS We are especially grateful to the Disney Wildlife Conservation Fund for providing core funding for the Zambia Crane and Wetland Conservation Program and the aerial and ground surveys described in this report. We are also grateful to WWF-Partners for Wetlands Program for providing funding assistance for the November aerial surveys of the Kafue Flats. Additional funding was also provided by the International Crane Foundation. We are very grateful to Dave Gunns of Dullstroom, South Africa, for generously volunteering his plane and piloting skills for the November aerial surveys. We thank also John Murphy of Airwaves Airlink for piloting the September aerial survey. Thanks also to Richard Jeffery for advice. We wish to sincerely acknowledge the Zambia Wildlife Authority for their help in procuring the authority to fly over the Kafue Flats from the Department of Civil Aviation and Zambia Airforce. Real Africa Safaris assisted us greatly during the reconnaissance flights in September, including permission to use their landing strip and free accommodation and refreshments. We also thank Star of Africa in Lochinvar National Park for their warm welcome when we visited their camp during the ground preparations. We thank the WWF Country Office for logistical support. We are grateful to Chuma Simukonda of the WWF Partners for Wetlands Program for his participation in the aerial surveys. We are also grateful to the South Africa Crane Working Group, especially Lindy Rodwell and Kerryn Morrisson, for assisting with the surveys. We thank also Carlos Bento of the Museum of Natural History, Maputo-Mozambique, Friday Maozeka of Harare-Zimbabwe, and Katie Beilfuss of the Urban Open Space Foundation, Wisconsin-USA, for their participation in the aerial and ground surveys. FOREWORD The Zambia Crane and Wetlands Conservation Project, under the auspices of the International Crane Foundation-USA, aims to conserve cranes and their wetland habitats in Zambia, with special emphasis on the sustainable management of the Kafue Flats ecosystem. The ZCWCP is part of a regional program that is investigating the role of Wattled Cranes as a flagship species for wetland conservation and management in Southern Africa. The ZCWCP works in close collaboration with other government and non-government organizations in Zambia, especially the WWF Partners for Wetlands Program and the Zambia Wildlife Authority for the benefit of the people and wildlife that share Zambia’s wetland resources. This report, Population and distribution of Wattled Cranes and other large waterbirds on the Kafue Flats, Zambia, provides the results from recent fieldwork and aerial surveys that assessed the population and distribution of Wattled Cranes and other waterfowl of international importance in the Kafue Flats during September and November 2001. A second report, Population of large mammals on the Kafue Flats, Zambia, provides the results from an aerial census of large mammals on the Kafue Flats during November 2001. This views expressed in these reports are intended to stimulate discussion and debate on the status of the wildlife and wetlands of the Kafue Flats. Readers are encouraged to provide comments to the authors for incorporation into future drafts.

3

TABLE OF CONTENTS

1.0 INTRODUCTION ...............................................................................................................................5

2.0 OVERVIEW OF THE KAFUE FLATS ..............................................................................................7

2.1 CLIMATE AND HYDROLOGY OF THE KAFUE FLATS.........................................................9

2.2 VEGETATION OF THE KAFUE FLATS ..................................................................................15

3.0 WATTLED CRANE AND WATERBIRD SURVEYS ON THE KAFUE FLATS ........................17

3.1 METHODS.....................................................................................................................................17

3.2 RESULTS........................................................................................................................................19

3.3 DISCUSSION.................................................................................................................................22

3.4 FURTHER RESEARCH................................................................................................................24

4.0 REFERENCES....................................................................................................................................26

4

1.0 INTRODUCTION

Of the six species of cranes that occur in Africa, two species occur in Zambia and live and breed on the Kafue flats, the Wattled Crane (Bugeranus carunculatus) and the Grey Crowned Crane (Balearica pavonina). The Wattled Crane is the largest, rarest, and most wetland-dependent of the African cranes, and is classified as a global endangered species. Most Wattled Cranes occur in the extensive floodplains of southern Africa’s large river basins (most notably the Zambezi and Okavango basins), although they are also found in the smaller isolated dambos of parts of Zambia, Zimbabwe, and South Africa (Figure 1). An isolated population of Wattled Cranes also occurs in the highlands of Ethiopia, and may soon be classified as a genetically distinct sub-species (Ken Jones, pers. comm.).

Figure 1. Distribution of Wattled Cranes (shaded area) in southern Africa, showing core concentration in the floodplains of Zambia and northern Botswana extending to southeastern Angola, southeastern DRC, western Tanzania, central Mozambique, and northeastern Namibia, with more isolated populations in the highland dambos of Zimbabwe, Malawi, and South Africa. (Source: Meine and Archibald 1996). The status of Wattled Cranes in Zambia and elsewhere in southern Africa is uncertain. Urban (1985, 1996) estimated the global population of Wattled Cranes at about 13,000-15,000 birds, with 7,000 – 11,000 birds occurring in Zambia. The IUCN (International Union for Conservation of Nature) Red Data Book suggests that the global population is only about 7,000 birds,

5

however (Collar and Stuart, 1985). A recent coordinated international survey effort in Botswana, Mozambique, South Africa, Tanzania, and Zambia suggests that the population may even be less than 7,000, with no more than 4,000 Wattled Cranes in Zambia. Wattled Cranes are distributed throughout most of Zambia (Figure 2), and are resident in all major wetland systems of Zambia including the Bangweulu Swamps, Lake Mweru Wantipa swamps, Lake Tanganyika swamps, Barotse Plain, Liuwa Plain, Busanga Swamps, Lukanga Swamps, and Kafue Flats.

Figure 2. Distribution of Wattled Cranes in Zambia, according to their recorded presence in quarter degree-squares (Source: Dodman 1996). The population of Wattled Cranes on the Kafue Flats has attracted particular attention because of the potential negative effects of Itezhitezhi and Kafue Gorge Dams on natural flooding patterns in the flats (Douthwaite, 1974, Konrad, 1980, Howard & Aspinwall, 1984). In undisturbed floodplain systems elsewhere in Africa, the breeding cycle of Wattled Cranes is intimately linked to the natural flood cycles of rivers. Wattled Crane pairs are “triggered” to nest as floodwaters begin receding after peak flooding. Nesting in shallow open water after the major flood rise and crest ensures that nests will be protected from predators and wildfires but will not be drowned by further rising floodwaters. As floodwaters slowly recede, Wattled Cranes raise their single chick on the pulse of exposed plant and insect life (Konrad 1981), especially tubers of the Eleocharis spike rushes (Beilfuss 2000). When flooding patterns are erratic or mistimed, Wattled Crane pairs may not be induced by hydrologic conditions to initiate nesting. Where nesting is attempted, unanticipated water level rises can drown nests and food sources. Rapid

6

water level drawdown in the floodplains may expose nests to wildfires and predators and limit food availability. Prior to dam construction on the Kafue River, Douthwaite (1974) observed that whereas 40% of Wattled Crane pairs attempt to breed in a year of normal flooding conditions, only 3% of all pairs breed in a year of negligible flooding conditions due to drought. When the Itezhitezhi Dam altered the hydrological regime of the Kafue Flats, Konrad (1981) predicted a dramatic restriction in Wattled Crane nesting sites and feeding area. Despite these concerns, there have been no detailed studies of Wattled Cranes and wetland biodiversity in the Kafue Flats during the past 25 years of Kafue River regulation. At the 1993 African Crane and Wetland Training Workshop held in Maun, Botswana, Dodman (1996) raised concerns that there was limited breeding activity on the Kafue Flats during 1992 (drought year) and 1993 (normal precipitation). There have been no additional studies since that time. In 2000, the Zambia Crane and Wetland Conservation Project (ZCWCP), under the auspices of the International Crane Foundation, was launched to address these concerns by investigating the status and ecology of Wattled Cranes in Zambia, with particular emphasis on the conservation and management of Wattled Cranes and wetlands in the Kafue Flats— a Wetland of International Importance under the Ramsar Convension. The ZCWCP is part of a regional program that is investigating the role of Wattled Cranes as a flagship species for wetland conservation and management in Southern Africa. The ZCWCP works in close collaboration with other government and non-government organizations in Zambia, especially the WWF Partners for Wetlands Program and the Zambia Wildlife Authority for the benefit of the people and wildlife that share Zambia’s wetland resources. From September to November 2001, the ZCWCP, in cooperation with the WWF Partners for Wetlands Programme and the South African Crane Working Group (SACWG), undertook a comprehensive survey of Wattled Cranes and other important species in the Kafue Flats. In this report, Population and distribution of Wattled Cranes and other large waterbirds on the Kafue Flats, Zambia, we assess the population and distribution of Wattled Cranes and other waterfowl of international importance in the Kafue Flats. We also describe the hydrological and ecological characteristics of the Kafue Flats as they affect Wattled Cranes and the overall biodiversity and productivity of the floodplain. A second report, Population of large mammals on the Kafue Flats, Zambia, provides the results from an aerial census of large mammals on the Kafue Flats during November 2001. 2.0 OVERVIEW OF THE KAFUE FLATS The Kafue Flats occur in southern Zambia between 150 11'-160 11' S and 26000-28016’E (Figure 3). Lusaka, the capital of Zambia, is located 50 km northeast of the Kafue Flats. The flats cover an area of approximately 6,500 km2 of floodplain grassland along course of the lower Kafue River between Itezhitezhi Gorge and the Kafue Gorge (Figure 4). The flats are recognized as a Wetland of International Importance under the Ramsar Convention, and are protected in part by two national parks, Lochinvar (approximately 440 km2) on the south bank and Blue lagoon (410km2) on the north bank, and the large Kafue Flats Game Management Area (5170 km2) that surrounds both parks. About 60% of Blue Lagoon and 50% of Lochinvar National Park are located on the floodplain proper and are inundated by annual floodwaters.

7

Figure 3. Map of Zambia showing the location of the Kafue Flats study area. The core protected area and periphery of the Kafue Flats is occupied by seven chiefdoms, and is densely settled with more than 120,000 residents (Jeffery 1992). The indigenous Ilas and Tonga communities are principally engaged in rearing and marketing cattle. Both Lochinvar and Blue Lagoon were cattle ranches before they were declared as National Parks in the 1970s, and the remaining flats are heavily grazed. The cattle population on the flats probably exceeds a quarter million head. Subsistence and small-scale farming is also important at the floodplain periphery, and includes the production of maize, cotton, and sunflower. Large-scale irrigated sugar estates occur at the eastern end of the flats. Subsistence fishing is also very important on the Kafue Flats, and is undertaken primarily by Batwa communities and immigrant fishermen (Jeffery 1992). The Kafue Flats fishery is one of the most important in Zambia (Subramanium 1992). Both local and non-resident (especially urban) communities are engaged in hunting activities on the flats, and wildlife populations have been severely over-exploited in the past (Howard and Jeffery 1983). There is no major industrial activity practiced by local communities in the flats. Water supply for agriculture and domestic use in Kafue Flats region is tied to a series of water rights with a total maximum allowed use of 15 m3/s. More than half of this water returns to the system, however, so maximum net water use is less than 7 m3/s (Kasimona and Makwaya 1995). Dams on the Kafue River, both upstream and downstream of the flats,

8

have greatly affected the communities that subsist on the floodplain by altering annual flooding patterns. These hydrological changes are described below.

Figure 4. Map of the Kafue Flats region showing the location of Lochinvar and Blue Lagoon National Parks and areas liable to flooding along the Kafue River. Itezhitezhi Dam occurs upstream of the flats. Major towns near the flats include Mazabuka, Namwala, and Ngoma.

2.1 CLIMATE AND HYDROLOGY OF THE KAFUE FLATS The Kafue River drains a catchment area of 154,000 km2 in central Zambia. The climate in the Kafue basin includes two distinct seasons, a 5 month wet season from November to March and a 7 month dry season from April to October. Maximum and minimum temperatures in the Kafue Flats region range from about 19-36oC in October and 0-21o C in July. Rainfall patterns are controlled by the movement of the Inter-Tropical Convergence Zone or ITCZ. The ITCZ is the convergence of three distinct air currents, the South East Trade Winds of the Indian Ocean that cover Mozambique and Zimbabwe, the North East Monsoon (an extension of the air stream flowing out of the Asiatic High from the Arabian Sea that covers the East African coast), and the Congo Air (a monsoonal in-draught across the west coast of Africa that covers the Zambezi basin from a north easterly direction). The convergence between the South East Trade Winds and the Congo Air is generally aligned in an east-west direction, while the convergence between the North East Monsoon and the Congo Air lies in a north-south alignment. From November to March, the ITCZ moves south over the Kafue Basin. The convergence is identified with a shallow trough of low pressure. The trough may deepen at times, or closed centers of low pressure may develop in areas where convergence is intensified. These troughs move slowly as a function of surrounding pressure changes, but may remain near stationary for extended periods of time. When centers of low pressure form equatorial lows over southern Angola or northern Botswana, conditions are favorable for the moist Congo Air to move in and produce large rainfall events across the Kafue basin. From April to October,

9

the ITCZ shifts north and the Kafue basin is influenced by a zone of high pressure with warm, sunny conditions (Balek 1977). The Kafue River headwaters rise on the plateau of the South Equatorial Divide in the Copperbelt region of Zambia. The Upper Kafue basin (50,480 km2) includes the Munyonshi and Luswishi tributaries and is largely mountainous and forested with headwater dambos (Balek and Perry 1973). The Kafue River is deeply incised in this region with fairly steep gradients and rapid runoff (FAO 1968). Annual rainfall averages 1100-1200 mm (Table 1) (Beilfuss and Santos 2002). Table 1. Mean monthly and annual rainfall for selected stations in the Kafue River catchment. Ndola and Kasempa are in the Kafue headwaters and Lufupa sub-catchments of the Upper Kafue basin, respectively. Choma is in the Middle basin and Lusaka is in the Lower basin. Station Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Ann Ndola 24 130 278 282 246 177 37 4 0 0 1 2 1181 Kasempa 39 142 255 248 212 171 38 3 0 0 1 4 1106 Choma 21 94 190 200 174 100 25 5 0 0 0 2 813 Lusaka 16 87 195 227 188 98 26 4 0 0 0 1 843 Average 27 113 227 233 202 135 34 4 0 0 0 3 977

Downstream of the Luswishi confluence, the Kafue River bends sharply to the west and the south bank opens up into the vast Lukanga Swamp (2600 km2). During peak flow periods, Kafue floodwaters spread overbank and inundate the floodplain through the Munwinu and Lukanga channels (Macrae 1934). The Lukanga Swamp significantly attenuates Upper Kafue basin runoff; reducing and delaying flood peaks downstream. Dry season evaporation losses from floodplain exceed 1100 mm/annum (Beilfuss and Santos 2002). Below Lukanga Swamps, the middle Kafue River flows west and captures runoff from the vast Lunga and Lufupa catchments. Runoff from the Lufupa catchment is attenuated by the Busanga Swamps (600 km2) within Kafue National Park. Further downstream, the Kafue cuts through an extensive ridge of Kalahari sand (1000-m amsl) at Itezhitezhi Gorge. The gorge has been dammed to form Itezhitezhi Reservoir, which is used to regulate the Kafue River for downstream hydropower generation. Itezhitezhi controls about 70% (105,620 km2) of the total Kafue catchment (Beilfuss and Santos 2002). Peak flows, attenuated by Lukanga Swamp, typically occur about two months after peak rainfall over the upper catchment. Annual runoff to Itezhitezhi Gorge is given as a percentage of the long-term (92-year) mean annual discharge in Figure 5 (Beilfuss and Santos 2002). Mean annual runoff is 8.8 x 109 m3 (279 m3/s), with a coefficient of variation of 0.50. The maximum probable flood discharge at Itezhitezhi is about 4250 m3/s (SWECO 1971). Below Itezhitezhi Gorge, the lower Kafue River meanders over the Kafue Flats, an extensive floodplain area up to 60 km wide and 250 km long with an average gradient of only 2.7 cm/km. Meanders, oxbows, and abandoned channels occur throughout the floodplain. Along its course, the Kafue River is fed by a series of flashy tributaries--including the Mbuma, Baunza, Banga, Lukomezi, Nansenga, Lutale, Nkala, Nanzhila, Sikaleta, Itu, Nangoma, Mwembeshi, and Kaleya Rivers--that drain from the surrounding plateau through numerous small sandy

10

deltas at the floodplain margin. The total subcatchment draining directly to the Kafue Flats is about 45,300 km2 (Hughes and Hughes 1992)

0

50

100

150

200

250

300

350

1907

1910

1913

1916

1919

1922

1925

1928

1931

1934

1937

1940

1943

1946

1949

1952

1955

1958

1961

1964

1967

1970

1973

1976

1979

1982

1985

1988

1991

1994

1997

Perc

enta

ge o

f mea

n an

nual

flow

(m3 /s

)

Figure 5. Time series of annual runoff at Itezhitezhi Gorge, as a percentage of mean annual flow, showing the variability of annual runoff flowing into the Kafue Flats (from Beilfuss and Santos 2002). Before construction of the Itezhitezhi Reservoir, seasonal runoff from the Kafue River and its tributaries inundated the Kafue Flats to create a mosaic of floodplain grassland and permanent lagoons (Handlos 1982). Most of the Kafue Flats is underlain by heavy (montmorillonite) vertisols or “black clays” derived from deep Quaternary sediments. Water levels in the flats start to rise in late November or early December, shortly after the onset of rains in the lower Kafue basin, and the clay soils expand and become impermeable. At this time, a flood crest would form at the western end of the flats below Itezhitezhi Gorge, spilling overbank across the floodplain. Floodwaters would proceed slowly eastwards, taking 80-90 days to traverse the flat, densely vegetated plain. Between December and February, runoff from local tributaries contributed to the widespread shallow flooding throughout the flats (Shawinigan Lavalin and Hidrotécnica Portuguesa 1990a). Floodwaters typically peaked at the eastern end of the Kafue Flats in April/May, well after the local rains had ended. Hydrographs of mean monthly runoff upstream and downstream of the Kafue Flats, showing attenuation of peak runoff by the floodplain, are given in Figure 6. The historical peak annual flood was about 500 m3/s, with a 100-year flood of about 3000 m3/s (Sichingabula 2000). During very wet years, up to 5650 km2 of floodplain was inundated. The vast extent of shallow floodwaters across the Kafue Flats resulted in very high evaporative

11

water losses (Table 2). Potential evaporation exceeds rainfall in all except the peak rainfall months. Net evaporation over the annual hydrological cycle is about 1050 mm (Beilfuss and Santos 2002). Table 2. Mean monthly and annual evaporation, rainfall, and net evaporation (mm) from the Kafue Flats. Evaporation is estimated from the Penman (1948) equation using data from the Namwala meteorological station. Data Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Ann Evap 171 148 167 144 115 93 102 130 168 205 177 164 1784 Rainfall 16 76 164 195 156 97 27 5 1 1 0 1 739 Net evap 155 72 3 -51 -41 -4 75 125 167 204 177 163 1045

Below the Kafue Flats, the river cascades through Kafue Gorge, dropping 600 m over a distance of 24 km. The entrance to the Kafue Gorge was dammed to form the Kafue Gorge Reservoir. Beyond the Kafue Gorge and the foot of the escarpment the river flows across the floor of the Rift Valley to join the Zambezi some 60 km downstream of Kariba Dam. The total length of the Kafue River from source to confluence is 1550 km. The first dam on the Kafue River was completed at the Kafue Gorge site in 1972. Kafue Gorge Dam is a gravity, earth-rockfill dam, with a crest height of 50 m at 981.5 m amsl. Kafue Gorge Dam operates to re-regulate outflow from the Itezhitezhi Reservoir through the Kafue Gorge hydroelectric station. Six turbines generate 900 MW at capacity, with a maximum discharge of 252 m3/s. Total reservoir capacity is 885 x 106 m3, with a dead storage of 20 x 106 m3. The normal operating level of Kafue Gorge is 975.3 m from August to November, rising to full retention of 976.6 m from December through March. At full retention level, the Kafue Gorge reservoir inundates the eastern half of the Kafue Flats up to Lochinvar National Park. From 600-1600 km2 of former seasonally inundated floodplain is permanently inundated by the dam, such that the downstream half of the Kafue Flats is now considered part of Kafue Gorge reservoir (Turner 1984, Chabwela and Siwela 1986). The difference between the annual maximum and minimum water levels was reduced from 4-5 m to 1.2 m (Balasubrahmanyam and Abou-Zeid 1982b). Because high evaporation losses from the Kafue Flats reduces the water available for power generation at Kafue Gorge, a second dam was designed to stabilize river flows below 250 m3/s, the discharge at which overbank flooding occurs (DHV 1980). Construction of Itezhitezhi Dam commenced in 1973 and began impounding water in December 1976. The dam is a gravity earth-rockfill dam, with a crest height of 65 m and length of 1800 m. Reservoir capacity is 5700 x 106 m3, with a dead storage of 780 x 106 m3 (SWECO 1971). The reservoir was designed with extra storage capacity to enable prescribed flood releases to the Kafue Flats over a four-week period in March each year. Net evaporation from Itezhitezhi Reservoir is about 780 mm/annum. Releases from Itezhitezhi Dam are dictated by power generation needs at Kafue Gorge Dam, typically about 168 m3/s except during periods of exceptional runoff from the upper catchment areas. During a four week period each March an ecological freshet of 300 m3/s is supposed to be released (DHV 1980), but this has rarely occurred in recent years. As a result, the extent of flooding in the western portion of the Kafue Flats has been greatly reduced (Sharma 1984). Before impoundment, flow in the western flats ranged from 30-1400 m3/s, with a mean maximum inundated area of 4820 km2 (Minderhoud 1982). Under current conditions, only intermittent flooding occurs in the western flats, with erratic dry season flows (Chabwela 1992).

12

In 1991-92, maximum monthly flows in the lower Kafue occurred at the end of the dry season in October (Sichingabula 2000).

0

100

200

300

400

500

600

700

800

900

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Flow

(m3 /s

)

Upper Kafue River flow at ItezhitezhiLower Kafue River flow at Kafue Gorge

0

50

100

150

200

250

300O

ct

Nov Dec Jan

Feb

Mar

Apr

May Jun Jul

Aug Sep

Rai

nfal

l (m

m)

Figure 6. Average mean monthly rainfall in the Kafue catchment above the Kafue Flats and hydrographs of mean monthly runoff upstream and downstream of the Kafue Flats, 1907-69, showing attenuation of peak runoff by the floodplain (from Beilfuss and Santos 2002). The affect of Kafue River regulation on mean monthly flows in the Kafue Flats is given in Figure 7. On average, peak flows through the Gorge have been reduced by 27% during the months of April, May, and June. There has been a corresponding increase in low flows during September-December, with the annual minimum monthly flows at the end of the dry season nearly three times the historical rate. Annual peak monthly runoff from the Kafue catchment varied from 105-1918 m3/s prior to river regulation, with a maximum daily inflow of 2629 in 1977/78, but mean maximum monthly runoff since 1971 is only 448 m3/s. Mean annual runoff has decreased only slightly since construction of Kafue Gorge Dam, from 288 to 260 m3/s, suggesting that the reduction in evaporative water losses from the Kafue Flats since regulation has largely offset the reduced catchment runoff during the prolonged regional drought of the 1980s and early 1990s. The direct effects of hydropower generation on Kafue runoff since 1977 are illustrated in Figure 8. Flows downstream of Itezhitezhi Reservoir, already attenuated by Lukanga Swamp, have been reduced a further 37% on average during the peak runoff months of February-April. Peak flows below Kafue Gorge Dam, delayed 2-3 months by Kafue Flats and the Kafue Gorge Reservoir, show significantly lower seasonal variation (163-340 m3/s) than upper-middle catchment runoff (49-717 m3/s).

13

0

100

200

300

400

500

600

700

800

900

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Flow

(m3 /s

)Kafue Gorge flows, 1907-1969

Kafue Gorge Dam outflow, 1970-1999

Figure 7. Hydrographs of mean monthly outflow from the Kafue Flats, before and after construction of Kafue Gorge Dam (from Beilfuss and Santos 2002).

0

100

200

300

400

500

600

700

800

900

Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep

Flow

(m3 /s

)

Itezhitezhi Dam inflow

Itezhitezhi Dam outflow

Kafue Gorge Dam outflow to Zambezi River

Figure 8. Hydrographs of mean monthly inflows and outflows at Itezhitezhi Reservoir, and outflows at Kafue Gorge Dam, 1977-98 (from Beilfuss and Santos 2002).

14

Future development projects may further effect the Kafue Flats. Proposed new water resources developments in the Kafue catchment include the Itezhitezhi Hydroelectric Power Plant and Kafue Gorge Stage 3. The proposed Itezhitezhi power plant would be built adjacent to the existing Itezhitezhi reservoir, with an installed capacity of 120 MW. The plant would be operated 24-hours per day, with greater generation during an 8- to 10-hour peaking period during daylight hours (Harza Engineering and Rankin Engineering Consultants 1999). Kafue Gorge Stage 3 would utilize the remaining 200-m head downstream of the existing Kafue Gorge Dam. Total generating capacity would be 450 MW. Construction of these hydropower stations would greatly increase the total capacity of the Kafue system, and could alter reservoir management practices basin-wide through the potential for a significant increase in firm capability of a joint system involving other Zambezi hydropower installations (Shawinigan-Lavalin and Hidrotécnica Portguesa 1990a).

2.2 VEGETATION OF THE KAFUE FLATS Vegetation communities of the Kafue Flats include scattered woodland on the levees of the Kafue River and its tributaries, littoral, wet meadow, and floodplain grassland on the open flats, Papyrus sudd and aquatic macrophytes on permanent floodplain waterbodies, grassland on termitaria at the floodplain margin, palm savanna at the narrow floodplain-escarpment ecotone, and Acacia-Combretum woodland on the surrounding escarpment. Vegetation of the Kafue flats is complex and varies considerably in space and time as a function of edaphic conditions (hydrology, soils, topography) and disturbances such as fire and grazing (Ellenbroek 1987). Natural levees adjacent to the Kafue River and its tributaries result from the deposition of coarse sediments as floodwaters spread laterally overbank (e.g., Leopold et al. 1964). The levees are the highest features on the floodplain, sloping steeply towards the river and grading gradually towards the low-lying floodplain. Levees are inundated for a much shorter duration than the surrounding floodplain, and support tall grasses dominated by Vossia cuspidata with widely scattered woody species that can tolerate only periodic flooding such as Acacia albida, Borassus aethiopum, and Sesbania sesban. Cultivars are common near settlements, including Sorghum verticilliflorum (Ellenbroek 1987). The perennial Kafue River is devoid of vegetation. The extensive, gently sloping floodplain is almost entirely covered with a mix grassland communities that vary according to the depth and duration of flooding and grazing intensity, among other factors. Woody species are absent. The highest lying, outer edge of the floodplain is normally flooded to a shallow depth of 50 cm or less and is not flooded during dry years (Douthwaite and Van Lavieren 1977). This “littoral zone” is composed of open grassland with a variety of annual and perennial herbs, and is heavily trampled by lechwe during the period of high floodwater. Three grassland communities are recognized in the littoral zone, including a Sporobolus pyramidalis-Echinochloa colona association, a Vernonia glabra association, and a Cynodon dactylon association (Ellenbroek 1987). A narrow belt of Vetiveria nigritana occurs in almost a continuous belt around the floodplain. Littoral zone communities provide a wealth of food for waterfowl, including the sedge Eleocharis dulcis—the key food source for Wattled Cranes. The intermediate-lying floodplain is seasonally inundated to a shallow depth of about 50-100 cm during all but exceptionally dry years, and is composed of small, weak stemmed grasses that keep barely pace with rising floodwaters and collapse completely as flooding subsides (Ellenbroek 1987). Thick mats of collapsed vegetation cover the soil during the dry season, and maintain moist conditions during the dry season. Three different communities are recognized

15

in this zone, including Acroceras macrum water meadow, Panicum repens-Leersia denudata water meadow, and Paspalidium obtusifolium water meadow. Acroceras macrum communities are heavily used by lechwe when flooded, and grazed by zebra, wildebeest, and buffalo during the dry season. The Panicum repens-Leersia denudata dominated grasslands occur in areas that are slightly more deeply flooded. Eleocharis dulcis is also common in this association. After floodwaters subside, the stems of Leersia, Panicum, and Eleocharis collapse to form a dense vegetation mat on the soil surface, but continue to produce new growth and remain green during the dry season. This grassland is heavily used by lechwe when flooded, as well as thousands of Spurwing Geese, ducks, and other waterbirds including Wattled Cranes. The grasses are grazed by zebra and wildebeest during the dry season. The Paspalidium obtusifolium water meadow is similar in composition to the Panicum repens-Leersia denudata grassland, but mainly occurs along incoming streams on the edge of the floodplain is typically inundated for a greater depth and duration. As with the other water meadows, it provides an important food source for lechwe and many species of waterfowl. The low-lying floodplains grasslands -- seasonally, deeply inundated with water levels often exceeding 1.5 m at high flood – are the most extensive plant community on the Kafue Flats. The Vossia cuspidata-Echinochloa scabra dominated grasslands include coarse, thick stemmed grasses that float in the water, rise above peak flood levels, and remain upright when floods recede. Other important grasses in this association are Oryza longistaminata, Brachiaria rugulosa, and Leersia hexandra (Ellenbroek 1987). Species composition changes from year-to-year depending on flooding conditions. The period of inundation often exceeds six months, and may be perennially flooded during very wet years. Soil conditions remain moist throughout the dry season and stimulate new vegetative growth. After floodwaters recede, Vossia and Echinochloa provide valuable grazing grounds for lechwe, hippopotamuses, and cattle. They also sustain the floodplain fishery by providing shelter for young fish and food for herbivorous fishes. Oryza is unpalatable and often associated with very heavily grazed areas. Communities of aquatic macrophytes occur in floodplain water bodies such as lagoons, oxbow lakes, backwater swamps, and pans. Lagoons (parapotamon) are dead arms of the main channel that remain connected to the river throughout the year at their downstream end. Oxbows (paleopotamon) are disconnected meander bends, cut-off from the mainstem river when it migrated laterally across the floodplain. Oxbows are often bordered on their concave banks by ridges from relict levees that may support palm and deciduous woody species. Swamps, or sloughs, are deeply flooded areas of stagnant water that form in meander scrolls and along valley walls. Shallow pans or pools are isolated, ephemeral bodies that often dry out during the dry season. Lagoons and pans are typically colonized by submerged, floating-leaf, and surface floating macrophytes such as Utricularia foliosa, Aeschynomene fluitans, Nymphaea lotus, and N. caerulea, distributed according to local variation in temperature, nutrients, carbon dioxide supply, salinity, alkalinity, pH, and microclimate, as well as competition (Denny 1985b). Hydrological conditions in lagoons are dynamic, fluctuating with river levels, and support emergent species with a wide range of tolerance to changing water conditions such as Vossia cuspidata and E. scabra (Thompson 1985). OxBows and swamps, only connected to the river during overbank flooding events, have more stable hydrological conditions. Papyrus swamps (dominated by Cyperus papyrus) typically occupy these deepwater zones, with reedswamps of Phragmites australis and Typha latifolia common in more drought-prone or brackish environments (Thompson 1985). There is a fairly distinct boundary between these species of deep-flooded soils and those found on more

16

shallow-flooded vertisols (Gaudet 1992). As floodwaters recede, islands of floating papyrus Sudd often become stranded on the floodplain grasslands. Papyrus stands support a wide diversity of plants within them, especially climbers such as Ipomoea rubens. The papyrus is also well known for its productivity (Thompson, 1975) and supports a high density of birds, including several papyrus endemics. Papyrus are frequently burned by local people. Immediately above the high flood level, the floodplain margin is ringed by extensive grassland dotted with termite mounds. This termitaria zone may range from several hundred meters to more than 15 kilometers in width. Dominant grasses include Acroceras macrum in rain-flooded depressions, Panicum spp.-Setaria sphacelata on the intermediate plains, and Setaria incrassata-Hyparrhenia rufa at the escarpment ecotone in association with widely scattered woody species (Ellenbroek 1987). Trees and shrubs may also be present on the higher termitaria. Palm savannas occur at floodplain-escarpment ecotone where the water table is high throughout the dry season. Hyphaene ventricosa palm savannas occupy sandy soils at the high flood line, in association with Acacia spp. , Albizzia spp. Dominant grasses include Setaria spp., Panicum spp., and Eragrostis spp. Termite mounds are frequent. On more clayey soils at the floodplain margin, Borassus aethiopum becomes dominant, with an undergrowth of Hyparrhenia rufa and other tall grasses. Termite mounds are less common. Grazing pressure is low in this zone, and dry season fires are often fierce (Ellenbroek 1987). Rising above the Kafue Flats on the escarpment, associations of Acacia spp.-Combretum spp. (munga woodland), Colophospermum mopane woodland, Kalahari woodland, and miombo woodland dominate the surrounding landscape. Riparian woodland and forest occur along some of the tributary watercourses. 3.0 WATTLED CRANE AND WATERBIRD SURVEYS ON THE KAFUE FLATS

3.1 METHODS Between September and November 2001, a combination of ground and aerial surveys were commissioned for the Zambia Crane and Wetland Conservation Project. The goals of the surveys were to: • estimate the total population, population structure, and distribution of Wattled Cranes on

the flats; • characterize the wetland substrates used by Wattled Cranes; • estimate the total population and distribution of Kafue lechwe and other large mammal

species on the flats; • estimate the population of other waterbirds of international concern, including all species of

storks, pelicans, Spur Winged Geese, and Grey Crowned Cranes; and • assess ecological factors that may affect the management of the flats, including the presence

of settlements, livestock grazing, bush fires, invasive Mimosa pigra shrubs, and poaching activity.

Given the vast extent and diversity of the Kafue Flats, a total count of target wildlife species is virtually impossible, and sampling techniques are necessary. An initial reconnaissance flight was undertaken in September 2001 to map the limits to the distribution of Wattled Cranes on the Kafue Flats and assess the overall diversity and density of different waterbird species including Wattled Cranes, storks, pelicans, Spur Winged Geese, and Grey Crowned Cranes, and to subsequently use this information to develop a protocol for estimating the total

17

population of target species. Surveys were flown in a six Cessna 206 aircraft. Ten diagonal transects were flown across the Kafue Flats from west to east. Survey flights were flown at 90 meters above ground level, at an average speed of 100 knots. The pilot and the navigator used an in-cockpit Global Positioning Satellite (GPS) system to navigate. Five observers, two located on left side of the plane and three located on the right side, recorded all observations of Wattled Cranes, Grey Crowned Cranes, pelicans, storks, ibises, spoonbills, Spurwinged Geese, and other large birds that could be accurately identified from the air on each side of the aircraft. Observations of Kafue lechwe and other large mammals were also recorded. The survey reflected the diversity and status of the flats in the middle of the dry season. Supplemental ground survey work was also undertaken during September 2001 in Lochinvar and Blue Lagoon National Parks. Interviews were conducted with the local fishing communities on the Kafue Flats and staff of the Zambia Wildlife Authority (ZAWA) to gain insight about the seasonal distribution and abundance of Wattled Cranes and other species. Wattled Crane feeding areas were investigated to assess substrate condtions. Observations of settlements, livestock grazing, fishing activity, bush fires, invasive Mimosa pigra shrubs, and poaching activity were recorded. In November 2001, a comprehensive aerial survey was undertaken at the end of the dry season/onset of the rainy season. Surveys were again flown in a six Cessna 206 aircraft (Table 3). During the September reconnaissance survey, we established that all Wattled Cranes, the vast majority of all other waterbird species, and all Kafue lechwe were located between 150 30'-150 42' S and 27000-27038’E. These findings closely mirrored the limits of previous large mammal surveys on the Kafue Flats (ZAWA 1999), and the coordinates were designated as the survey limits for November survey. Because of the tremendous numbers of waterbirds observed on the flats in September, especially Spurwing Geese and African Openbill Storks, the survey team decided to restrict the number of waterbirds counted during the November survey to Wattled Cranes, Grey Crowned Cranes, Saddlebill Storks, pelicans, and large mammals. Other species observed were noted only. Observers estimated that Wattled Cranes, Saddlebilled storks, and large mammals could be accurately counted approximately 1 km on either side of the plane. Twenty transects, spaced 4 km apart and oriented north-south, were flown to provide 50% uniform coverage of target species on the Kafue Flats. Survey flights were flown at 90 meters above ground level, at an average speed of 100 knots. The pilot and the navigator used an in-cockpit Global Positioning Satellite (GPS) system to navigate. Table 3. Technical details of the November 2001 aerial survey Date of survey 27-28 November 2001 Aircraft type Cessna 206 (high wing) Total flying time 10 hours Average speed 120km/hour Average height 60 m Pilot David Gunns Navigator Richard Beilfuss Observers Richard Beilfuss, Ben Kamweneshe, Chuma Simukonda,

Kerryn Morrison, Lindy Rodwell Orientation of transects North-South Two observers, located on each side of the plane, recorded all observations of Wattled Cranes, Grey Crowned Cranes, Saddlebill Storks, and pelicans. Where Wattled Cranes were observed in pairs, observers searched for signs of nests or chicks. Where the cranes where observed in

18

groups of three birds or more, the aircraft was circled and flew at a lower altitude and observers had to discern whether the birds were adults or juveniles (as distinguished by head plumage). Where large crane concentrations were observed, the aircraft circled the population several times until an accurate estimate of the number of cranes and population structure of the group was obtained. Observers photographed larger flocks with a slide film, and later projected the slides to double-check estimates of the population and structure of these flocks. The second two observers recorded all observation of Kafue lechwe and other large mammals. Where large lechwe concentrations were observed, the aircraft circled the population several times until an accurate estimate of the number of was obtained. Observers photographed larger groups with a slide film, and later projected the slides to double-check estimates of the population. These findings are reported in a separate report, Population of large mammals on the Kafue Flats, Zambia. The fifth observer assisted with verifying Wattled Crane and waterbird observations, and recorded ecological factors that may affect the management of the flats, including the presence of settlements, livestock grazing, bush fires, invasive Mimosa pigra shrubs, and poaching activity. The total population estimate for Wattled Cranes, Grey Crowned Cranes, Saddlebill Storks, and pelicans was calculated based on the assumption that we observed 50% of all singletons, pairs, chicks, and small flocks (≤10 birds) and 100% of all large flocks (>10 birds) during the surveys, based on the total survey area coverage described above. We therefore extrapolated our counts of singletons, pairs, chicks, and small flocks by multiplying these counts x 2, but did not extrapolate our counts of large flocks. We estimate the number of birds per transect as well as the total population for the flats.

3.2 RESULTS The number of Wattled Cranes recorded in the transects flown together with the computed estimates of the total area covered. is shown in Table 4. A total of 756 birds were counted giving an estimate of 967 Wattled Cranes for the sampled area. The frequency of observed group sizes of Wattled cranes Is given in Table 5. Twenty-five percent of the observed population was in pairs or pairs with chicks, the remainder was in flocks of various sizes. One flock of 460 birds was observed in Blue Lagoon National Park. Other large flocks included groups of 35, 19, 17, and 14 birds, mostly on the northbank. Estimated numbers of other selected waterbirds observed on the Kafue Flats are given in Table 6. The flats are particularly important for Spurwing geese and African openbill stork, but support substantial numbers of many waterbird species. A complete list of other waterbirds (as defined by the Wetlands International list of sub-saharan African waterbird species) observed during either ground or aerial surveys in September and November 2001 is given in Table 7.

19

Table 4. Total number of Wattled Cranes counted and estimated for each survey transect and for the entire Kafue Flats, November 2001 Transect number

Coordinates Singles Pairs Chicks Flocks Total count

Total estimate

1 15030‘S 27000‘E-15050’S 27000’E

0 0 0 0 0 0

2 15050’S 27002’E-15030’S 27002’E

0 0 0 0 0 0

3 15030’S 27004’E-15050’S 27004’E

0 2 0 0 4 8

4 15050’S 27006’E-15030’S 27006’E

0 3 1 0 7 14

5 15030’S 27008’E-15052’S 27008’E

1 5 1 0 12 24

6 15052’S 27010’E-15029’S 27010’E

0 4 1 0 9 18

7 15029’S 27012’E-15053’S 27012’E

0 6 0 5 17 34

8 15053’S 27014’E-15032’S 27014’E

0 8 5 5 26 52

9 15032’S 27016’E-15052’S 27016’E

0 13 5 460 491 522

10 15052’S 27018’E-15033’S 27018’E

0 14 7 59 94 1

11 15033’S 27020’E-15053’S 27020’E

0 5 3 0 13 26

12 15053’S 27022’E-15030’S 27022’E

2 10 2 0 24 48

13 15030’S 27024’E-15052’S 27024’E

0 2 0 0 4 8

14 15052’S 27026’E-15028’S 27026’E

0 1 1 0 3 6

15 15028’S 27028’E-15048’S 27028’E

0 3 1 35 42 49

16 15048’S 27030’E-15027’S 27030’E

0 3 0 0 6 12

17 15027’S 27032’E-15044’S 27032’E

0 1 0 0 2 4

18 15044’S 27034’E-15025’S 27034’E

0 0 0 0 0 0

19 15025’S 27036’E-15042’S 27036’E

0 0 0 0 0 0

20 15042’S 27038’E-15030’S 27038’E

0 1 0 0 2 4

Total observed 3 81 27 564 756 Total estimated 6 162 54 583 967

20

Table 5. Frequency of observed group sizes of Wattled cranes on the Kafue Flats, November 2001 Group size Frequency of observation Sum of birds in group 1 3 3 2 54 108 3 27 81 4 1 4 5 3 15 14 1 14 17 1 17 19 1 19 35 1 35 460 1 460 Total 756

Table 6. Estimated numbers of selected waterbirds observed on the Kafue Flats. Species common name Scientific name Estimated

number Eastern white pelican Pelecanus onocrotalus <100 Pinkbacked pelican Pelecanus rufescens <20 Whitebreasted cormorant Phalacrocorax carbo >50 Reed cormorant Phalacrocorax africanus 100s Grey heron Ardea cinerea >20 Goliath heron Ardea goliath >40 Purple heron Ardea purpurea >20 Great egret Casmerodius albus 100s Intermediate egret Egretta intermedia >5000 Little egret Egretta garzetta 1000s Cattle egret Bubulcus ibis 1000s Yellowbilled stork Mycteria ibis >20 African openbilled stork Anastomus lamelligerus >10,000 Abdim’s stork Ciconia abdimii <20 Saddlebilled stork Ephippiorhynchus senegalensis <20 Marabou stock Leptoptilos crumeniferus >20 Sacred Ibis Threskiornis aethiopicus 100s African spoonbill Platalea alba >20 Fulvous whistling-Duck Dendrocygna bicolor 1000s Whitefaced whistling-Duck Dendrocygna viduata 1000s Spur winged goose Plectropterus gambensis >20,000 Knob-billed Duck Sarkidiornis melanotos <100 Egyptian goose Alopochenaegyptiacus <100 Grey Crowned Crane Balearica regulorum <20 Wattled Crane Bugeranus carunculatus <1000

21

Table 7. Other waterbirds (based on the Wetlands International list of sub-saharan African waterbird species) observed during both ground and aerial surveys in September and November 2001. Common Name Scientific Name Little grebe Tachybaptus ruficollis Blackheaded Heron Ardea melanocephala Slaty Egret Egretta vinaceigula Black Egret Egretta ardesiaca Squacco Heron Ardeola Rufousbellied Heron Butorides rufiventris Striated Heron Butorides striatus Glossy ibis Plegadis falcinellus Yellowbilled Duck Anus undulatata Hammerkop Scopus umbretta African Pygmy goose Nettapus auritus Redbilled Teal Anas erythrorhyncha Hottentot Teal Anas hottentota African Crake Crex egregia Black Crake Amaurornis flavirostris Common Moorhen Gallinula chloropus Lesser Morhen Gallinula angulata Purple Gallinue Porphyrio porphyrio Lesser Gallinue Porphyrula alleni Redbilled coot Fulica cristata African Jacana Actophilornis africanus Lesser Jacana Microparra capensis Blackwinged Stilt Himantopus himantopus Pied Avocet Recurvirostra avosetta Redwinged Pratincole Glareola pratincola Long-toed Plover Vanellus crassirostris Blacksmith Plover Vanellus amartus Senegal Wattled Plover Vanellus senegallus Crowned Plover Vanellus coronatus Ringed plover Charadrius hiaticula Kittlitz's Pover Charadrius pecuarius Three banded Plover Charadrius tricollaris Marsh sandpiper Tringa stagnatilis Greenshank Tringa nebularia Common sandpiper Actitis hypoleucos Wood sandpiper Tringa glareola Little stint Calidris minuta Ruff Philomachus pugnax Painted snipe Rostratula benghalensis Greyheaded Gull Larus cirrocephalus Caspian tern Sterna caspia Whiskered Tern Chlidonias hybridus African fish eagle Haliaeetus vocifer African marsh harrier Circus ranivorus Marsh owl Asio capensis

22

3.3 DISCUSSION The total estimated population of Wattled Cranes on the Kafue Flats (967 birds) is the lowest recorded since aerial surveys were first undertaken in the 1970s. The area sampled in this survey (between 150 25'-160 00'S and 260 42'-270 42'E) represents only 50% of the entire Kafue Flats study area, but covers the entire distribution of Wattled Cranes and most other important wildlife species, especially Kafue lechwe, based on reconnaissance surveys conducted prior to the intensive survey. The population of Wattled Cranes on the Kafue Flats was first estimated by Doutwaite (1974). Douthwaite estimated a total population of about 3,000 individuals on the flats at peak season, including about 300 breeding pairs (40% of the population). Konrad (1981) counted 552 Wattled Cranes on flats in 1978-79, including 180 pairs (64% of the population), only 20 chicks, and 172 non-breeding adults. Konrad did not report his census techniques nor provide a total population estimate, however. Dodman (1996) summarized the results of the most recent surveys of Wattled Cranes on the Kafue Flats, conducted between 1982 and 1993. In 1982, Howard and Aspinwall estimated 3,282 birds on the flats. Counts in November 1987 (Howard), May/June 1988 (Malambo), and August 1989 (Malambo) produced successive estimates of 2,508, 2,724, and 3,272 birds, respectively. These estimates were all generated from stratified random sampling techniques, as used for the survey of the Kafue lechwe population.`In 1993, three aerial surveys were conducted. Jeffery et al. (1993) estimated 809 Wattled Cranes on the flats in May 1993, based on the same stratified random sampling technique that was used for the 1980s counts. Dodman conducted two additional counts, one in January 1993 (1,373 birds) and one in July 1993 (1,268 birds), based on uniform survey coverage of about 15% of the flats. The average population based on all three aerial counts was only 1,150 birds. Thus, although it is possible that the estimates from the 1970s and 1980s were too high—based on difficulties in extrapolating from large flocks1—it seems very likely that there has been a substantial decline in the population of Wattled Cranes on the flats over the past 20 years, perhaps most significantly between the 1980s and 1990s. It is unknown whether this decline represents a real decrease in the global Wattled Crane population, or a shift in seasonal or annual distribution. Our 2001 survey provides about 50% coverage of breeding pairs and close to a total count for flocks greater than about 20 individuals. We recorded a large flock of more than 400 individuals on the southwest end of Blue Lagoon National Park (270 25'E/150 20'S). A smaller flock was observed in the same area during the reconnaissance flight in September. Although our results are not directly comparable with previous estimates, they are probably the most accurate count of Wattled Cranes to date and should form the basis for future comparisons. It is essential that subsequent surveys are conducted at the end of the wet season (June/July) to estimate seasonal changes in the population, and conducted at the end of the dry season (a repeat of the November survey) to estimate year-to-year changes in the population. Ultimately, surveys need to cover a range in hydrological conditions on the flats as a function of climate variability and perhaps other factors (especially the management of Itezhitezhi Dam) to more fully understand the population dynamics of Wattled Cranes on the Kafue Flats. Further conclusions on long term changes in the population should be delayed until those 1 Bob Douthwaite (pers. comm.) notes that he did not extrapolate from his counts in the 1970s and therefore made no allowances for birds he did not observe. He adds, “I think there can be very little doubt the crane population has significantly declined.”

23

surveys are completed. Similarly, minimal research has been conducted on the breeding success of Wattled Cranes since the work of Douthwaite (1974). This information is urgently needed to evaluate the effects of water regulation at Kafue Gorge Dam and Itezhtezthi Dam on the breeding population of Wattled Cranes. Based on our findings and results of previous surveys, it is clear that the lack of information on Wattled Crane movement and activities pose a considerable challenge to the successful management and conservation of these birds and their habitats. From past counts it is apparent that crane numbers tend to fluctuate considerably both between years and within years, but the patterns and locations of movement are unknown. Nesting activity occurs throughout the year, peaking between April/May and August (Benson et al. 1973), but nesting sites are widely distributed on the flats and frequently outside the two National Parks. Activity zones such as feeding, flocking, courtship, and nesting areas may be widely separated. We also need to better understand the degree that human activities such as fishing, agriculture, and cattle herding are disturbing Wattled Cranes. The peak breeding months for Wattled Cranes coincide with high levels of human activity in several areas. For example, cattle herds are moved onto the flats around May-July when upland fodder is limited. Uncontrolled fires were observed in several areas. On a larger scale, we need to understand how sudden flood releases from Itezhitezhi Dam effects the feeding and nesting activities of Wattled Cranes.

3.4 FURTHER RESEARCH Nationwide surveys In 2001, we identified survey areas for the nationwide Wattled Crane census from previous reports, discussions with other conservationists and village leaders, personal observations, and other sources. Survey areas include sites known to support Wattled Cranes, sites that formerly supported Wattled Cranes, and sites never before surveyed that may potentially support Wattled Cranes. We are organizing a network of volunteer counters to cover as many of the crane areas as possible throughout Zambia with a synchronized count during the 2001 and 2002 dry seasons. Counters are recording the location and number of Wattled Cranes and other waterbirds species observed at each survey site. These surveys are conducted by foot, car, or canoe. For those areas not covered by volunteer network, the project team is directly undertaking the surveys. Sites that are particularly large and inaccessible, such as the Bangweulu swamps, the Liuwa flats, Busanga Flats, and Lukanga Swamps, are being covered by systematic aerial surveys. In 2001, we conducted the first aerial surveys of Liuwa and Lukanga in more than 30 years. Aerial surveys are conducted with experienced observers using standard counting methods for waterbird surveys (Jolly 1969). Observations of other waterbirds of conservation concern are also recorded. Survey data are supplemented by the results of questionnaire surveys. Questionnaires have been distributed throughout the range of the Wattled Crane to all network members, bird clubs, government agencies, conservation organizations, and other interested organizations and individuals that have knowledge about the status and distribution of Wattled Cranes and their wetland habitats. The completed questionnaires are being used to compile data about the current and past distribution, population size, status and movements, diets, and breeding activity, as well as specific threats, local attitudes, legal protection, and other factors affecting the status of Wattled Cranes. The questionnaires are also used to gather information about

24

various ecological factors that may affect Wattled Crane distribution and abundance, and management practices at each wetland site. Survey and questionnaire results will form the scientific basis for a Wattled Crane Action Plan for Zambia. The action plan will include an assessment of the total population of Wattled Cranes in Zambia; the current and former distribution of Wattled Cranes; the main threats to Wattled Cranes across their current and former range; and the local attitudes about Wattled Cranes and wetlands. The plan will also identify and rank priority actions for the conservation of Wattled Cranes in Zambia. The draft Wattled Crane Action Plan will be circulated among survey participants and outside experts for comments and revisions prior to publication. Kafue Flats research Aerial surveys During September and November 2001, we undertook aerial surveys of the Kafue Flats to determine the population structure and seasonal distribution of Wattled Cranes, and the density and distribution of other species of international concern in the Kafue Flats. Follow-up surveys are planned for June 2002 (to assess seasonal changes) and November 2002 (to assess inter-annual changes). The surveys consist of a series of parallel transects, each approximately 50-60 km long, spaced 4 km apart. Transects are orientated in a north-south direction, using in-cockpit Global Positioning System navigation. Survey flights are flown at 90 m above ground level, at an average speed of 100 knots. Two observers, one on each side of the plane, record and compare data. Waterbird species that can be accurately identified, from 1 km on each side of the aircraft, are counted and recorded with a tape-recorder (Jolly 1969). At each site where Wattled Cranes are observed, the GPS co-ordinates and time of observation are recorded. If the cranes are observed in pairs, observers search for signs of nests or chicks. If the cranes are observed in groups of three birds or more, the aircraft circles and flies at a lower altitude so that observers can discern whether the birds are adults or juveniles (as distinguished by head plumage). Where large crane concentrations are observed, the aircraft circles the population several times until an accurate estimate of the number of cranes and population structure of the group is obtained. Observers also photograph larger flocks with slide film, and later project the slides to double-check estimates of the population and structure of these flocks. During the course of the surveys, observers are also recording and photo-documenting the types of habitats utilized by different waterbirds in the Kafue Flats, including rainfed dambos in the deciduous miombo (Brachystegia) forests on the floodplain fringes, seasonally inundated sedge and open grassland, deep swamp in lowland depressions of the floodplain, papyrus swamps in oxbow meanders, shallow open water bodies, open mudflats (during the flood recession period), and other communities. Observations of bush fires, hunting activities, agriculture developments, fishing activities, and human encroachment are also recorded. This information is enabling the identification of some of the specific threats to cranes and other waterbirds in the Kafue Flats. Ecological field research During the dry season of 2001, we conducted preliminary field surveys at Lochinvar and Blue Lagoon national parks. The preliminary surveys enabled us to plan for detailed fieldwork during the dry season of 2002. This year, field study sites are located at key areas where extensive breeding activity or non-breeding flocks are occurring, as identified from observations and GPS co-ordinates collected during aerial surveys. We will set-up simple camouflaged blinds to observe crane groups with a spotting scope. We will count and record the total number of chicks, juveniles, and adults in the flock. Feeding, breeding, and roosting

25

activity and other behaviors will be observed in 20-minute intervals for different individuals (Ellis et al. 1996). Where foraging activity is observed, the food source will be recorded for each time interval (e.g., probing for tubers, striping seeds, and hunting frogs, insects or fish). After the breeding season, nest material will be collected to analyze and determine the main material used by cranes for nest building. Key biotic and abiotic factors that may influence the utilization of habitat areas by Wattled Cranes will be measured and analyzed by step-wise multi-regression. These parameters include climate, hydrology, soil permeability, vegetation characteristics, and wildlife interactions. General climate parameters (wind direction, wind speed, air temperature) will be recorded at the center of each study site. If surface water is present, water temperature and surface water depth will be measured at multiple locations and averaged. The vegetation composition, structure, and rhizome abundance will be characterized for each study site. From the center of each study site, a circle of 50-m radius will be covered. Within this area, ten random sample points will be selected for vegetation sampling. At each sample site, percent cover will be measured by the line-intercept method, and rooted frequency as the presence or absence of a given species in a 0.25 m2 circular area. Vegetation density will be estimated at the sample points using visual estimate of cover over a checkered board with 5 x 5 cm subdivisions. Shrub and tree species, and their relative dominance (as estimated visually by percent cover of each dominant species), will be estimated within the entire study area. The ratio of open water to vegetated area will be visually estimated for each study plot. Rhizome abundance will be measured by excavating soil from a 1 m diameter subplot to a depth of 20 cm and counting the total number of rhizomes per soil unit. Rhizome samples will be collected at the three locations in the study site where vegetation density is measured, and averaged. We will look for evidence of the association between Wattled Cranes and other species in the Kafue Flats, including predation by other animals, competition with other species, and association with grazing and browsing activities. Interviews with community members Interviews with chiefs, fishers, cattle herders, resource managers, and others will be conducted concurrent with the ground surveys. Interviews conducted during 2001 yielded valuable information about the occurrence and movements of Wattled Cranes, threats to Wattled Cranes, ecological factors affecting Wattled Crane occurrence, wetland management practices, and local attitudes about Wattled Cranes and wetlands. We are collecting data on human use of the wetland site (e.g., conversion of wetlands for agriculture, livestock grazing, drainage, irrigation, vegetation harvest, tree cutting, agrochemical usage); the presence of utility lines, roads, and other land development; the direct exploitation (e.g., sport hunting, subsistence hunting, live trapping for commercial trade, and removal of eggs from nest) and poisoning (e.g., direct poisoning to protect crops and indirect poisoning due to use of agricultural chemicals) of Wattled Cranes; nesting site disturbances (e.g., fishing, hunting, or vegetation harvest activities near nest sites); and burning practices (e.g., fires for land clearing or bushmeat). Hydrological analyses Our hydrological analyses will include a statistical analysis of long-term flow data from the Kafue Flats, and a model of the operation of Itezhitezhi and Kafue Gorge Dams for hydropower production, to assess the potential for improved water management by better mimicking natural flood patterns using measured flow series. We will use Geographic Information System technology to determine long-term changes in flooding patterns and vegetation communities in the Kafue Flats, comparing data from 1960 airphotos and ground mapping efforts with current airphotos, satellite images, and aerial reconnaissance of the area. We will conduct socio-

26

economic surveys in different communities to determine the relationship between flooding patterns and economic activity in the Kafue Flats, and collect oral histories among village chiefs and elders to assess the changes in floodplain utilization over time resulting from hydrological and other changes in the floodplain system. Discussions with wetland managers In 2001, we initiated meetings with government officials, water resource managers, development agencies, rangers, and others involved with the management of the Kafue Flats to discuss past, present, and future proposed management activities. We will continue this process during the next year. Management activities include regulations affecting settlement patterns and resource utilization, water resources development, and fisheries and agricultural practices. We will assess each management practice in terms of its effects on Wattled Cranes and their habitats. We will also discuss the impact of the upstream Itezhitezhi Dam on the Kafue Flats, and compare changes in the hydrology and vegetation of the Kafue Flats over time using historical references. Dissemination of results Based on the findings of this research, we will publish and disseminate comprehensive recommendations for integrating Wattled Crane and biodiversity conservation with wetland management practices in the Kafue Flats. We will organize a high-level workshop at the end of the project period in cooperation with our project partners and involving all relevant stakeholders concerned with the management of the Kafue Flats. The workshop will pull together different experts on the hydrology, ecology, and management of the Kafue Flats, and discuss ways forward for linking biodiversity conservation with wetland management.

4.0 REFERENCES Balasubrahmanyam, C., and S.M. Abou-Zeid. 1982b. Post-Itezhitezhi flow pattern of the Kafue

in the Kafue Flats region. Pages 63-68 in G.W. Howard and G. J. Williams, eds. The consequences of hydroelectric power development on the utilization of the Kafue Flats. Proceedings of the National Seminar on Environment and Change: the Consequences of Hydroelectric Power Development on the Utilization of the Kafue Flats, Lusaka, April 1978. Lusaka: Kafue Basin Research Committee of the University of Zambia.

Balek, J. 1977. Hydrology and water resources in tropical Africa. Developments in Water Science 8.

New York, New York: Elsevier Scientific Pub. Co. Balek, J., and J.E. Perry. 1973. Hydrology of seasonally inundated African headwater swamps.

Journal of Hydrology 19: 227-249. Beilfuss, R and D. dos Santos. 2002. Patterns of hydrological change in the Zambezi Delta,

Mozambique. Working Paper #2 of the Program for the Sustainable Management of Cahora Bassa Dam and the Lower Zambezi Valley. International Crane Foundation, Baraboo, Wisconsin.

Beilfuss, R. 2000. Piecing together the story of an Africa floodplain: water, wetlands, and

Wattled Cranes. ICF Bugle 26(1):1-2. Beilfuss, R. and C. Bento. 1998. Impacts of hydrological changes on the Marromeu Complex of

the Zambezi Delta, with special attention to the avifauna. Proceedings of the Workshop on the

27

Sustainable Use of Cahora Bassa Dam and the Zambezi Valley, 29 September to 2 October, Songo, Mozambique.

Benson, CW., R.K. Broke, R.J. Brooke, Dowsett and M.P.S Irwin. 1973. The birds of Zambia. 2nd

Ed. Collin, London, UK. Chabwela, H.N. 1992. The ecology and resource use of the Bangweulu Basin and Kafue Flats.

Pages 11-24 in R.C.V. Jeffery, H.N. Chabwela, G. Howard, and P.J. Dugan, eds. Managing the wetlands of Kafue Flats and Bangweulu Basin. Proceedings of the WWF-Zambia Wetlands Project Workshop, 5th-7th November, 1986. IUCN, Gland, Switzerland.

Chabwela, H.N. and Siwela, A.A. 1986. The vegetation structure of the Kafue Flats North Bank

after the construction of the dams In: proceedings of E.W.R.S/AAB 7th Symposium on Aquatic Weeds. Loughborough University, Loughborough, UK. Pp.61-72

Collar, N.J & Stuart, 1985). Threatened birds of Africa and related islands. The ICBP/IUCN

Red Data book, Part 1. Cambridge: ICBP/IUCN DHV. 1980. Hydrological study of the Kafue Flats: final report. Amersfoot, The Netherlands. Dodman, T. 1996. Present status and distribution of cranes in the Kafue Flats, Zambia with

reference to population estimates of the 1980's. Pages 255-259 in R. Beilfuss, W. Tarboton, and N. Gichuki, eds., Proceedings of the 1993 African Crane and Wetland Training Workshop. International Crane Foundation, Baraboo, Wisconsin.

Douthwaite, R. J. 1974. An endangered population of Wattled Cranes. Biological Conservation 6:

134-142. Douthwaite, R.J. 1982. Waterbirds: their ecology and future on the Kafue Flats. Pages 137-140 in

G.W. Howard and G.J. Williams, eds., Proceedings of the National Seminar on Environment and Change: the consequences of hydroelectric power development on the utilization of the Kafue Flats, Lusaka, April 1978. Kafue Basin Research Committee, University of Zambia, Lusaka.

Douthwaite, R. J. & van Lavieren. L.P. 1977. Description of vegetation of Lochinvar National

Park, Zambia. Technical Report No. 34. National Council for Scientific Research, Lusaka, Zambia. 66pp.

Ellenbroek, G.A. 1987. Ecology and productivity of an African wetland system: the Kafue Flats,

Zambia. Geobotany No. 9. W. Junk. Dordrecht, Netherlands. ISBN 90-6193-638-1. 267 pp. FAO. 1968. Wildlife, fisheries amd livestock production . vol.5. Multipuprose Survey of the Kafue

River Basin, Zambia. Report FAO SF: 35/ZAM FAO, Rome, Italy. 7 volumes. Gaudet, J.J. 1992. Structure and function of African floodplains. Journal of the East Africa Natural

History Society and National Museum 82 (199): 1-32. Howard, G.W & Aspinwal, D.R. 1984. Aerial censuses of shoebills Storks, Saddlebills Storks

and Wattled Cranes at the Bangweulu Swamps and Kafue Flats, Zambia. Ostrich 55: 207-212.

28

Howard and G.J. Williams, eds., Proceedings of the National Seminar on Environment and Change: the consequences of hydroelectric power development on the utilization of the Kafue Flats, Lusaka, April 1978. Kafue Basin Research Committee, University of Zambia, Lusaka.

Harza Engineering Company International and Rankin Engineering Consultants.1999.

Feasibility study of the Itezhitezhi Hydroelectric Project. Vol. 4. Environmental Impact Assessment. Lusaka: Zambia Electricity Supply Corporation.

Hughes, R.H. and Hughes, J.S. 1992. A Directory of African Wetlands. IUCN, Gland / UNEP,

Nairobi / WCMC, Cambridge. Hughes, R.H. and Hughes, J.S. 1992. A Directory of African Wetlands. IUCN, Gland / UNEP,

Nairobi / WCMC, Cambridge. Jeffery, R.C.V. 1992. The Kafue Flats of Zambia: a case study. Pages 57-70 in T. Matiza and H.N.

Chabwela, eds. Wetlands Conservation Conference for Southern Africa. Jeffery, R.C.V., H.N. Chabwela, G. Howard, and P.J. Dugan, eds. 1992. Managing the wetlands

of Kafue Flats and Bangweulu Basin. Proceedings of the WWF-Zambia Wetlands Project Workshop, 5th-7th November, 1986. IUCN, Gland, Switzerland.

Jolly, G.M. 1969. Sampling methods for aerial census of wildlife populations. E. Afr. Agric. For.

J. 34:46-49. Konrad, P.M, 1980. The present status of the Wattled Cranes in Africa. International Crane

Foundation, Wisconsin, USA Kamweneshe, 1996. The status and ecology of wattled cranes in the Bangweulu Basin. Pages

261-265 in R. Beilfuss, W. Tarboton, and N. Gichuki, eds., Proceedings of the 1993 African Crane and Wetland Training Workshop. International Crane Foundation, Baraboo, Wisconsin

Kamweneshe, 1996. Local People as Partners in Wetlands Conservation: A case study of

Community Based Management. Pages 267-271 in R. Beilfuss, W. Tarboton, and N. Gichuki, eds., Proceedings of the 1993 African Crane and Wetland Training Workshop. International Crane Foundation, Baraboo, Wisconsin

Kamweneshe, B & Malambo, C. 1988. Preliminary observations of the distribution and

abundance of Wattled Crane in Zambia Wetlands. (Unpub;ished) Kasimona, V.N & Makwaya, J.J. 1995. Present Planning in Zambia for the Future use of

Zambezi River Waters. In: Proceedings on Water Resource use in the Zambezi Basin. IUCN, 173 pp.

Konrad, P.M. 1981. Status and ecology of Wattled Crane in Africa. Pages 220-237 in J. C. Lewis

and H. Masatomi, eds., Crane Research Around the World. International Crane Foundation, Baraboo, Wisconsin, USA.

Leopold, L.B., M.G. Wolman, and J.P. Miller.1964. Fluvial processes in geomorphology. New York:

Dover Publications. Macrae, F.B. 1934. The Lukanga Swamps. Geographical Journal 83: 5-9.

29

Minderhoud, P. 1982. Kafue Flats hydrological studies. Pages 59-62 in G.W. Howard and G. J.

Williams, eds. The consequences of hydroelectric power development on the utilization of the Kafue Flats. Proceedings of the National Seminar on Environment and Change: the Consequences of Hydroelectric Power Development on the Utilization of the Kafue Flats, Lusaka, April 1978. Lusaka: Kafue Basin Research Committee of the University of Zambia.

Pomeroy, D. E. and B. Tengecho. 1986. A Method of Analyzing Bird Distributions. African

Journal of Ecology 24(4): 243-253. Sharma, T.C. 1984. Hydrological changes in the Kafue Basin. Pages 10-27 in W.L. Handlos and

G. Williams, eds. Development of the Kafue Flats-the last five years. Lusaka: Kafue Basin Research Committee of the University of Zambia.

Shawinigan-Lavalin and Hidrotécnica Portuguesa. 1990. Simulation of Kafue Gorge Power Plant operation: Hydroelectric Hydrological Assistance Project - Phase 1.SADCC 3.0.4.

Sichingabula, H.M. 2000. Hydrogeomorphological characteristics of the Blue Lagoon National Park and

adjacent Game Management Areas, Kafue Flats region. Report prepared for the Zambia Wildlife Authority. Chilanga, Zambia.

Subramanium, S.P. 1992 A brief review of the status of the fisheries of the Bangweulu Basin and Kafue Flats. Pages 45-56 in H. N Chabwela, R. C. V Jeffery, G. Howard, and P.J. Dugan, eds. Managing the wetlands of Kafue Flats and Bangweulu Basin. Proceedings of the WWF-Zambia Wetlands Project Workshop, Musungwa Safari Lodge, Kafue National Park, Zambia, 5th-7th November, 1986. Gland: IUCN.

SWECO. 1971. Kafue River Hydroelectric Power Development Stage II. Itezhitezhi Reservoir and extension of Kafue Gorge upper power station. Preinvestment study. Stockholm, Sweden.

Tarboton, W. 1984. The status and conservation of Wattled Cranes in the Transvaal. Pages 665-

670 in J.A. Ledger, ed., Proceedings of the Fifth Pan-African Ornithological Congress. Southern African Ornithological Society, Johannesburg.

Tembo, A, ed. 1995. Zambia Wetlands Project: workplans and budgets. National Parks and

Wildlife Service, Chilanga, Zambia. Thompson, K. 1975. Productivity of Cyperus papyrus . In: J.P. Cooper (ed) Photosynthesis and

productivity in different environments. IBP/Cambridge University Press. Timberlake, J. (1998). Biodiversity of Zambezi Basin Wetlands: review and preliminary

assessment of available information. Phase 1. Final report. IUCN-ROSA, Harare, Zimbabwe. Turner, B. 1984. The effect of dam construction on flooding of the Kafue Flats. Pages 1-9 in W.L.

Handlos and G. Williams, eds. Development of the Kafue Flats-the last five years. Lusaka: Kafue Basin Research Committee of the University of Zambia.

Urban, E.K. 1988. Status of cranes in Africa. Pages 315-329 in G.C. Backhurst, ed. Proceedings of

the Sixth Pan-African Ornithological Congress. Nairobi, Kenya.

30

Urban, E.K. 1996. Status of Cranes in Africa, 1994. Pages 53-59 in R. Beilfuss, W. Tarboton, and N. Gichuki, eds., Proceedings of the 1993 African Crane and Wetland Training Workshop. International Crane Foundation, Baraboo, Wisconsin.

Zambia Wildlife Authority. 1999. Large mammal surveys in the Kafue Flats. Unpubl. MS.

31