The observations and interviews reported in this study were conducted in the North-eastern deserts of the Sudan, including the Butana plains, Gash delta and the Southern frontiers of the Nubian desert (Atbara River basin). However, most of the work concerns Butana as a traditional home of camel pastoralists in North-eastern Sudan (see Map Annex 8).
Butana is situated well within the arid zone of the Sudan and occupies an area of approximately 120,000km2 and lies between Latitude 13° 40' N to 17° 50' N and Longitude 32°to 36° E. Butana consists of five subregions, namely the North, Central, Southern, Western and Eastern subregions. The largest are the Central (Butana proper) and Northern subregions. The Western region is a narrow strip of land along the Blue Nile while the Eastern subregion adjoins the Atbara River. Most of the Butana is a series of flat easily flooded plains interspersed by few hills. Towards the west, the Butana is separated from the Nile valley by a discontinuous series of hills. Geographically Butana consists of the Nubian series (sandstone and mudstone) in the West and North and of the rocky Precambrian basement complex in the centre, south and eastern regions. There are at least two distinct soil types in the Butana; namely a red sand or loamy sand soil over the Nubian series and a brown heavy soil over the basement complex (Saint-Martian et al., 1992).
Over most of the Sudan, the prevailing climate is a tropical continental climate, ranging from sub-equatorial conditions in the South to desert in the North. In the Butana region the climate is influenced by the north and south oscillations of the boundary of the Intertropical Convergence Zone (ITCZ) between dry northerly winds and moist southerly winds. This ITCZ reaches its northern limit in summer (rainy season) and its southern limit in winter (dry season). The duration of the rainy season (June-September or October) is determined by the southerly winds. Most of the rains are in the form of showers or thunderstorms. Early in summer and up to the advent of rains, sandstorms are very common. Another characteristic of rainfall in this region is its variability from one year to the other, estimated by Abu Sin (1970) to have a coefficient of variation as high as 45% in most of the area and 20% in the smaller southern part (Annex 1).
During the last decades, Butana has been subjected to severe overgrazing due to the convergence of several tribes into this area which is famous for its open grazing potential. This trend increased specially after abolishing the "native administration". The latter used to provide range management regulations which were respected by host tribes and herders specially those not residing in Butana. The spread of cultivated land to occupy most of the Southern Butana has also increased the grazing pressure on the drier western and northern subregions (Suliman, 1985).
According to El-Hassan (1981) the highly nutritive Blepharis edulis (Siha) is the climax vegetation of the Butana if no or little grazing takes place. This highly platable and nutritious plant has now virtually disappeared (Suliman, 1985). Gradually, Aristida spp. (Gow), Cymbopogon nervatus (Nal) and Schoenefldia gracilis (Dembelab) dominate (Pflaumbaum and Kirk, 1992). Many unpalatable grasses appear to be on the raise, e.g Ocimum basilicum (Rehan), specially in the more fertile central and southern regions and Brachiaria lata (Taffa) just north of rainfed cultivation schemes. According to pastoralists the latter plant cannot be grazed when young, which could explain its vigorous spread (Soliman, 1985).
In the Southern subregion, the basement peneplain is characterized by an extensive woody cover comprising mainly Acacia mellifera (Kitir), Calotropis procera (Usher), Capparis decidua (Tundub) and grasses. The adjacent zone further north is characterized by grassy areas with an estimated plant cover of 65%, while the woddy vegetation in this subregion could be found only in Wadis (Shallow basins). Further to the north the grass cover eventually decreases to grassy patches with an estimated grass cover of 25%, comprised mainly of Aristida spp. and Panicum turgidum (Tumam). Trees in this subregion feature Acacia tortillis (Seyal) and Capparis decidua (Tundub). Both trees produce highly nutritious pods and browsing foliage or twigs (Abbas and Musa, 1986) [Annex 2]
In years of good rainfall, the Butana is an extensive field of green grasses, legumes and young trees (Fig. 1). However, in years of bad rainfall there is almost complete failure of perennial or annual plant growth (Fig. 2).
Figure 1: Butana Range in a Good Year (1996)
Figure 2: Butana Range in a Below-average Year (1990)
Livestock ecology and management procedures practiced by pastoralists utilizing Butana, Gash and Atbara rivers range were the subject of an extensive survey conducted by a team of researchers from Sudan (Camel Research Unit) and France (IEMVT). The methodology and findings of this research have been presented (Abbas et al., 1992). A brief account is given herewith. A total of 822 herds were surveyed during the rainy season and an interdisciplinary set of data was collected. Whereas 85% of the surveyed herds belonged to individual owners, 15% were multiple owners who practiced group herding. There were at least four herding strategies adopted by the pastoralists utilizing Butana range (Abbas et al., 1992). The four systems differed significantly in several factors, notably, herd size moving as one group, level of sedentarization, the use of labour, owner's supportive activities, camel uses, dry season feeding, and the variable species composition of the herd. The overall predominant feeding strategy was the use of Butana range in the rainy season and either crop residues or riverain or coastal habitat (Red Sea, Atbara River, Gash, Rahad) during the dry season. In this regard, 395 herds out of a total of 708 (56%) had come to Butana from outside (Red Sea region, Eritrea, Gash, Nile, Gezira etc..) of whom 269 (38%) were classified as transhumant and 126 (18%) were nomadic (Maillard, 1992). They left Butana around September-October admittedly because of lack of water. This usually leaves most of the range for exploitation by Butana resident pastoralists who usually have much smaller herds of livestock (camel, sheep, goats and cattle). Butana residents obtain water from Haffirs up to December-January in favourable years (Fig. 3), shallow wells in stream beds, and a few tube wells throughout the year. A clear trend towards specialization was noticed with increasing interest in feedlotting of camels (and sheep) and the rearing of racer camels to make use of the growing demand for meat and sport animals in the Gulf and Saudi Arabia as well as Egypt. Analysis of herder's age structure and owners' backgrounds disclosed that pastoralism is still found profitable by many tribes, attracting new investors, some of whom were former traders and expatriate farmers (Le Horgre, 1993).
During the rainy season, there is tremendous mixing between diverse cultures in the Butana. This results in sharing of experiences and inputs on different aspects of animal breeding, husbandry and diseases. Added to the antiquity of pastoralism among the Butana people, the enrichment that could be realized as a result of these encounters would indeed make keen healers knowledgeable and informed about practices originating far away in the continent. Additionally, healers in the area use soil and plant sources not available locally. These are provided by pastoralists or herders from West Africa or Ethiopia, and are also availed by numerous traders (Attarin Sing Attar) of herbs who are found in the marketing centres of Kassala, Gedaref, Omdurman, Eddimer and New Halfa.
Figure 3: Camels are watered from Haffirs well after the rainy season. The plastic sheet is for protecting water from contamination and for salt addition
Information about various aspects of ethnoveterinary practices in the study area was collected by direct interviewing of known healers who accepted to share their knowledge and to explain at length the foundations of their practices. In the first few hours of encounter with each healer, base-line data was collected about the healer, sources and speciality (Annex 3, Annex 7).
Following sessions were centred on recording in detail the various inputs of each healer's practice as well as the theoretical or philosophical notions. In general, healers were interviewed (and visited) at least three times over a six month period. These visits were made to coincide with the two main seasons: the rainy season (July-September) and the dry season (November-April). This breaking of the time schedule allowed an excellent variation in the healers undertakings, coinciding with remarkable seasonal change in the ecosystem as a whole. It also allowed the sampling and demonstrating (by the healers) of different plants with attributable healing (or toxic) potential.
A total of 15 well-known healers (all men) were interviewed in Butana, Gash and Nile Province (see results and Annex 3). The information collected was very diverse and a lot of effort was necessary to summarize the different views and formulae presented by these healers. Five healers were the subject of intensive study and repeated visits.
Only those herders who were willing to allocate some of their time for lengthy interview were approached. Herders-predominantly managing camel herds were asked to relate the signs and local nomenclature adopted to refer to specific diseases. They were also asked whether they would prefer to contact a traditional healer or a veterinarian in case of trouble and whether they preferred traditional or universal (western) medicines. Herders were also asked to relate their experiences relevant to the aetiology and risk factors for certain diseases. Each herder was also asked to recall his own experience in handling diseased animals and if need be, whether he will carry out any surgical interventions. A total of 56 herders were thus interviewed in the same areas where healers were encountered. These interviews extended from 1992 to 1996 (Agab and Abbas, 1995).
Several plants mentioned or utilized by the healers were sampled (leaves, flowers [±seed], stem, root) and were compressed in locally made presses for taxonomic purposes. Speciation was carried out at the Departments of Botany, Faculty of Science and Faculty of Agriculture, University of Khartoum. In a few instances the seeds had to be germinated under controlled conditions so as to ascertain a specific ecotype or species.
A few plants with therapetuci-nutritional potential were desiccated (leaves, pods or seed) and analysed following conventional procedures. Such analysis included vitamin A, protein and ash content. The anthelminthic potential of some plants, a commonly encountered observation, was subjected to laboratory examination using on-going projects at the Department of Veterinary Medicine, Faculty of Veterinary Science, University of Khartoum. The latter researches will be presented separately when experiment and analytic work are completed.
