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A review of the status of forest elephants Loxodonta africana in Central Africa
Biological Conservation 71 (1995) 125-132
ELSEVIER
0006-3207(94)00014-X
Elsevier Science Limited Printed in Great Britain 0006-3207/95/$9.50
A REVIEW OF THE STATUS OF FOREST ELEPHANTS L O X O D O N T A AFRICANA IN CENTRAL AFRICA R. F. W. Barnes,* A. Blom & M. P. T. Alers Wildlife Conservation Society, The International Wildlife Conservation Park. Bronx, New York 10460-1099, USA (Received 5 October 1993; revised version received 5 January 1994; accepted 9 January 1994)
Abstract The status of elephants Loxodonta africana in the central African forests in 1989 is reviewed These elephants accounted for about one-third of the continental total. However, there are few data on numbers, for only one of the six countries in the region has been censused. The estimates for the other countries came from a limited set of dung-counts or a model based on those dung-counts. Poaching for ivory was widespread in four of the six countries, but the lack of census data makes it difficult to assess its impact. The distribution of elephants was determined by the intensity of poaching, the distribution of roads and settlements, and the distribution of secondary forest. Ivory exports from central Africa accounted for about one-third of the continental total in 1979-1988, but this included an unknown proportion of ivory from savanna elephants. While poaching is the most urgent short-term threat, the problems posed by expanding human activities in the forest zone need to be addressed by national elephant conservation plans. The main constraints on elephant management are the general lack of information on basic forest elephant biology, the weakness of government wildlife departments, corruption, the vast areas to be covered, the difficulty of access to remote forests, and the impossibility of surveillance from the air.
In the 1970s and 1980s, a wave of ivory poaching swept across Africa (Douglas-Hamilton, 1987, 1988; Cobb, 1989). Sixty percent of the ivory exported from Africa came from the equatorial forests (Parker, 1979), yet no data were available on forest elephant numbers, trends, or distribution. Accordingly, Wildlife Conservation International (now re-named NYZS The Wildlife Conservation Society) organised a programme of field work to establish the status of elephants in the central African forests. In this paper we draw together the results from six countries, and combine them with the findings of the Ivory Trade Review Group (Cobb, 1989) to present an overview of the elephant situation at the end of 1989 in the equatorial forests of central Africa. Late 1989 is an appropriate point in time because four of the six countries were surveyed that year (Fay, 1991; Fay & Agnagna, 1991; Alers et al., 1992; Barnes et al., 1993), and in January 1990 the CITES ban on the international ivory trade came into effect (Western, 1990).
THE EQUATORIAL FORESTS The forests of central Africa cover about 1.75 million km 2 (FAO/UNEP, 1981) in the centre of the continent (Fig. 1). They include parts of six countries: Cameroun, Central African Republic (CAR), Congo, Equatorial Guinea, Gabon, and Zaire. White (1983) classifies the central African forests as Guinea-Congolian rain forest and gives a general description. Overviews of the status of the forests of the separate countries are given by Letouzey (1968), Reitsma (1988), Breteler (1989), Gartlan (1989, 1992), Kendrick (1989), Doumenge (1990), Hecketsweiler (1990), Wilks (1990), Carroll (1992), Fa (1992), N'Sosso & Hecketsweiler (1992), Sayer (1992), and Yutin (1992).
Keywords." Central Africa, forests, elephants. INTRODUCTION During the last three decades, the elephant Loxodonta africana has been one of the most intensively studied animals on the African continent. However, most research has focused on the elephants of the relatively open habitats of eastern and southern Africa. Those in the dense forests of central Africa have been ignored by the majority of biologists. Even the most basic information, such as the size of the elephant population in the equatorial forests, was for a long time the subject of speculation (Anon, 1984; Douglas-Hamilton & Douglas- Hamilton, 1992).
FOREST ELEPHANTS Two sub-species of African elephant are recognised. In west Africa, Loxodonta africana cyclotis is found in the forest while L. a. africana occurs in the open habitats, with intermediate forms seen in transition zones (Roth & Douglas-Hamilton, 1991). In central Africa the situation is less clear cut and both sub-species, and hybrids, occur in the forest zone (Western, 1986; Carroll,
*To whom correspondence should be addressed at: Department of Biology 0116, University of California at San Diego, La Jolla, California 92093-0116, USA 125
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R. F. W. Barnes, A. Blom, M. P. T. Alers
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Fig. 1. The rain forest countries of central Africa. 1, Cameroun; 2, Equatorial Guinea; 3, Gabon; 4, Central African Republic (CAR); 5, Congo; 6, Zaire. International f r o n t i e r ; - - - - Boundary of rain forest; Atlantic Coast. 1988: Barnes et al., 1993; Lahm, 1993). Because elephants are difficult to see in forest, the distributions of the two sub-species are not known. In some forests both are found, while elsewhere only one occurs. Stories of the existence of a pygmy elephant (L. a. pumilio), originally described by Noack (1906), have been explained as juvenile elephants (Pfeffer, 1960; Western, 1986). However, Anon. (1990) claims that much of the evidence in favour of the pygmy elephant has been overlooked. ELEPHANT NUMBERS AND DISTRIBUTION
The dense canopy and thick undergrowth of the forest zone makes direct counts of large mammals difficult, whether from the air or the ground. Instead, forestdwelling mammals are normally censused by indirect methods, such as counts of dung or nests (Short 1983; Tutin & Fernandez, 1984; Merz 1986; Barnes & Jensen, 1987; Koster & Hart, 1988; Barnes et al., 1991; Barnes, 1993). The most intensive elephant census work has been conducted in Gabon. In northeastern Gabon there was a strong correlation between elephant density and perpendicular distance from the nearest road or village (Barnes et al., t991). At the time of that survey there was little ivory poaching, and so the low elephant
densities close to villages and roads were the result of elephants avoiding human activity. The gradient of elephant density was modified by the presence of secondary forest, which is the result of human settlement and agriculture in the past, and is the preferred habitat for forest elephants (Merz, 1981; Barnes et al., 1991). The distance from the nearest road and the percentage of transects covered by secondary forest explained three-quarters of the variance in elephant numbers in northeastern Gabon (Barnes et al., 1991). The highest elephant densities were found in remote forests which had been inhabited by shifting cultivators until the 1950s or 1960s. The abandoned villages and plantations left a mosaic of primary and secondary forest favoured by elephants (Barnes et al., 1991). These large expanses of forest, now undisturbed by human activity, explain the high estimates of elephant numbers for Gabon. A stratified sample census based on dung-counts gave an estimate of 62,000 with 95% CL of +20,000 (R. F. W. Barnes, A. Blom, M. P. T. Alers & K. L, Barnes, unpublished data). Michelmore et al.'s (in press) figure of 55,000 may be an under-estimate because it is based upon White's (1983) vegetation map which underrepresents Gabon's forest area compared with other maps. In 1989 a reconnaissance was made of the forests of four countries (Cameroun, CAR, Congo, and Zaire), in order to obtain preliminary data on the status of elephants
Central A f r i c a n . & r e s t elephant status
Table 1. Estimates of the numbers of elephants remaining in central Africa
Country
Cameroun CAR Congo Equatorial Guinea Gabon Zaire Total
Estimated number Estimated combined of forest elephants number of forest in 1989" and savanna elephants in 1989~ 12,000 2,000 31,000 400 55,000 72,000
18,000 23,000 32,000 400 60,000 97,000
172,400
230,400
"Calculated by Michelmore et al. (in press). hNumbers of savanna-dwellingelephants calculated from data in Douglas-Hamilton (1989). as a basis for planning systematic surveys in the future (Fay, 1991; Fay & Agnagna, 1991; Alers et al., 1992; Barnes et al., 1993). Elephant density gradients similar to that in Gabon were found in CAR, Congo, and Zaire (Fay, 1991; Fay & Agnagna, 1991; Alers et al., 1992. Since these gradients in relation to human disturbance appear to be a general rule governing elephant distribution in the sparsely-populated forests of central Africa, Michelmore et al. (in press) incorporated them into a model for estimating forest elephant numbers (Table 1). The forests of northern Congo still harboured a large population of elephants in 1989, despite evidence of considerable poaching activity (Fay & Agnagna, 1991). Elephant densities were estimated to be higher in this area than anywhere else in the forest zone with the exception of southeastern Cameroun (Fay & Agnagna, 1991). The abundance of elephants can be explained by the marked gradient of elephant density in relation to human settlements and the large expanses of uninhabited forest (Fay & Agnagna, 1991). In contrast, the forests of southern Congo were heavily settled and have long been disturbed by logging and heavy hunting. As a consequence, the elephant population was fragmented into four sub-populations (M. Agnagna, R. F. W. Barnes, & M. Ipandza, unpublished data). The forest elephant model gave an estimate of 31,000 for Congo (Table 1). This is probably an over-estimate because it does not account for elephants leaving the swamp forests of northeastern Congo in the wet season (Fay & Agnagna, 1991). Therefore the average density in the swamps over the year is probably lower than that estimated by the model. Large parts of Cameroun's southwestern and southcentral forests are densely settled and elephants remain only in isolated pockets (Barnes et al., 1993). An exception is the Korup area close to the Nigerian frontier. It is in the sparsely inhabited forests of the south-east that most of Cameroun's elephants are found. Stromayer and Ekobo (1992) recorded very high densities in the extreme southeastern forests, indicating a much larger forest elephant population for Cameroun than the 12,000 estimated by Michelmore et al. (in press) (Table 1).
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Forest covers only a small part of CAR, in the southwest and in the southeast. Carroll (1986) and Fay (1991) reported high elephant densities in the extreme southwestern forests, which lie adjacent to the frontiers with Cameroun and Congo. However, few signs of elephants were seen in the eastern part of the southwestern block, where there was a higher human density (Fay, 1991). Elephants were found to be abundant in the southeastern forest block of CAR (Fay, 1991). This was a surprising result because of the reports of heavy poaching there. Elephants may have moved into those forests to avoid the even heavier poaching outside (Fay, 1991). The numbers of elephants in CAR's savanna zone had been cut by 80% between 1976 and 1985 (DouglasHamilton, 1987), and Fay (1991) concluded that a disproportionately high number of CAR's remaining elephants, about 6,000, were to be found in the forest zone. The model gave an estimate of only 2,000 forest elephants for CAR (Table 1). The difference between the two figures is because higher elephant densities occurred in the southeast and extreme southwest (Carrol, 1986; Fay, 1991) than predicted by the model. Only a few hundred elephants are thought to remain on the mainland of Equatorial Guinea, which is a small and densely populated country (Table 1). They are found in the southern part of the country (M. P. T. Alers &Blom, unpublished data). The remote forests of Zaire, covering about 1 million km 2, have long been thought to harbour a large elephant population (Anon., 1984; Douglas-Hamilton & Douglas-Hamilton, 1992). The collapse of the road infrastructure since Independence (Whitaker, 1988) should, according to Michelmore et al.'s (in press) model, have benefited elephants. However, there are reports of large numbers being killed during the last 30 years (Barnes, 1987). Alers et al. (1992) found evidence of heavy ivory poaching in the forest zone. Poachers used the extensive river system to hunt elephants in the remotest forests, and elephants appear to have been eradicated from large areas of forest (Alers et al., 1992). The numbers of elephants remaining in the forests of Zaire have been calculated by Michelmore et al. (in press) to be 72,000 (Table l). However, this does not account for the unknown area of forest from which elephants have been eliminated. Alers et al. (1992) made an approximate estimate of elephant numbers by using the density estimates from their study areas and assuming that they exist at very low density (0.01 per km ~) over the rest of the forest zone. This gave a figure of 64,000 elephants. These studies have shown the overwhelming importance of human activities in determining elephant abundance in the central African forests. Humans influence elephant densities in three ways. First, elephants avoid sources of human disturbance such as roads and villages, even in the absence of ivory poaching. Second, poaching reduces elephant numbers. This is illustrated by the curve relating elephants to roads, which was shallower for those countries with heavy poaching compared with Gabon, where there was little poaching (MicheImore
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R. F. W. Barnes, A. Blom, M. P. T. Alers
et al., in press). Thirdly, elephants' preferred habitat.
secondary forest, is created by human activity. The first two factors have a negative effect on elephant abundance, while the third has a positive effect. Thus the highest densities of elephants were found in the remote sparsely-populated zone spanning the corners of four adjacent countries: northeastern Gabon, southeastern Cameroun, northern Congo, and southwestern CAR (Fig. 1). This zone represents the most important single area for forest elephants on the continent. Altogether, about 170,000 forest elephants were estimated by Michelmore et al. (in press) to remain in the central African forests (Table 1). This figure is lower than the estimate of 214,000 presented by an earlier version of the same model (Michelmore et al., 1989), largely because of new information on defecation and decay rates (Tchamba 1992; Barnes & Barnes, 1992). Adding the numbers of savanna-dwelling elephants (calculated from the tables in Douglas-Hamilton, 1989) gives a total central African population of 230,000 (Table 1). Douglas-Hamilton (1989) estimated the numbers of elephants in eastern, southern, and western Africa to be 110,000, 204,000, and 19,000 respectively. Therefore, based on his figures and those of Michelmore et al. (in press), in 1989 the central African forest population accounted for about one third of the continental total of 563,000.
IVORY P O A C H I N G Effect of ivory poaching on numbers
The impact of ivory poaching on elephants in the central African forests has been described in qualitative terms by Barnes (1987), Barnes et al. (1991), Fay (1991), Fay & Agnagna (1991), Alers et al. (1992) and Barnes et al. (1993). Large-scale commercial poaching has been especially severe in Zaire, Congo, and Cameroun, while Gabon seems to have escaped. No census work was done before the poaching upsurge, and the recent reconnaissance surveys covered only a very small part of the elephants' range. Therefore it is difficult to estimate directly the impact on elephant numbers caused by poaching. However, Michelmore et al. (1989) made an indirect assessment by comparing the present distribution of elephants with a model of the distribution before the poaching upsurge. This suggested that ivory poaching had reduced forest elephant numbers by over 40%. Evidence from the ivory trade
A large proportion of the ivory exported from Africa comes from elephants killed illegally (Luxmoore et al., 1989; Cumming et al., 1990). Large quantities of ivory have been smuggled from one country to another within central Africa (Douglas-Hamilton, 1979; Allaway, 1989a, b; De Meulenaer & Meredith, 1989; Meredith, 1989; Fay & Agnagna, 1993). Much ivory has also been exported illegally from central Africa. For example, most of the ivory exported from Zaire was smuggled into neighboring countries or flown out
illicitly (Douglas-Hamilton, 1979; De Meulenaer & Meredith 1989; Fay & Agnagna, 1993). Between 1979 and 1988, 955 tonnes of ivory were exported from Congo (Luxmoore et al., 1989), but only 540 tonnes (or 57%) appear in Congolese government records (Meredith, 1989). The rest was presumably smuggled. Even less was recorded in Cameroun and Gabon. The Camerounian customs recorded only 2.5% of the ivory exported from Cameroun in 1979, 1980, 1982, 1985 and 1988 (Allaway, 1989a). The Gabonese customs recorded less than 1% of the ivory exported from Gabon between 1983 and 1988 (Allaway, 1989b). Luxmoore et al. (1989) used the records of the importing countries to estimate the volume of ivory exported (both legally and illegally) from each African country. The largest quantities were exported by CAR, Congo, and Zaire (Table 2). The figure for Zaire is almost certainly an under-estimate because much ivory was smuggled out and exported from its neighbours (De Meulenaer & Meredith, 1989; Fay & Agnagna, 1993). The volumes in Table 2 represent 36% of the maximum continental total estimated by Luxmoore et al. (1989) for that decade. However, these figures include tusks from elephants killed in both the forest and savanna zones, and the proportion coming from each zone is unknown. Thus although the central African countries made a significant contribution to the continental ivory trade in 1979-1988, one cannot estimate the overall contribution of central African forest elephants. In East Africa poaching has distorted the age structure of elephant populations as well as reducing numbers (Poole, 1989; Barnes & Kapela, 1991). Changes in tusk weights can sometimes be used to deduce changes in age structure (Barnes & Kapela, 1991), because there is a relationship between tusk weight and age (Pilgram & Western, 1989). However, in central Africa tusks are smuggled from one country to another and large tusks are often selected out and smuggled along one route leaving the smaller tusks to pass along another (De Meulenaer & Meredith, 1989). Thus the distribution of tusk weights recorded for each country does not reflect the original weight distribution of tusks from elephants killed in that country. Further, the records do not distinguish between tusks from L. a. cyclotis and L. a. africana, nor between males and females, Since the Table 2. Quantities of raw ivory exported from the central African countries between 1979 and 1988 (from Luxmoore et al., 1989)
Country
Cameroon CAR Congo Equatorial Guinea Gabon Zaire Total
Total ivory exported 1979 1988 (tonnes) 37 1,098 955 No data 27 705 2,822
Central African forest elephant status relationship between tusk weight and age is different for the two sub-species, and differs between sexes for each sub-species, an analysis of age structure is impossible.
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3). Furthermore, in Gabon and Equatorial Guinea human densities have been declining because the exodus to the towns exceeded the birth rate (Table 3). Thus the conflicts between humans and elephants may not have been as serious as in the more densely populated parts of the continent. On the other hand, in Gabon the rural exodus will reverse because of changing economic circumstances (Lahm, 1993), and in general throughout the region human populations are increasing (World Bank, 1986). Elephants have been displaced or eradicated by expanding villages and agriculture in the southwestern and central parts of the forests of Cameroun, and from the forests of southern Congo and CAR, and in Zaire from the environs of Kisangani and the heavily populated edges of the forest block. The further spread of villages and agriculture will inevitably increase competition between men and elephants for land in the forest zone. This will be exacerbated by deforestation. At present the rate of deforestation in central Africa is low (FAO/UNEP, 1981), but it is accelerating (Barnes, 1990; WRI, 1992). The decrease in forest combined with the increasing human population will cause a rapid decline in per capita forest resources (Barnes, 1990). This will mean less room for elephants. At the same time the forests will be fragmented, as in west Africa (Martin, 1991; Roth & Douglas-Hamilton, 1991). As each large block of forest is broken into smaller parcels, elephants will become more vulnerable to human disturbance. Logging is a major industry in central Africa and is spreading through the forests. For example, logging companies are moving into the forests of southeastern Cameroun, northern Congo, central Gabon, and central Zaire (Nicoll & Langrand, 1986, Doumenge, 1990; Horta, 1991; Tutin, 1992; Wilkie et al., 1992). In Gabon the area of undisturbed forest is expected to decline from 82,000 km 2 in 1986 to between 44,000 and 59,000 km 2 in 1997 as a result of the expansion of the logging industry (Nicoll & Langrand, 196). Logging can have a positive effect on elephants by creating patches of secondary vegetation favoured by elephants (Dudley et al., 1992); but it can also have a negative impact, because the new roads provide poachers with access to remote forests (e.g. Fay & Agnagna, 1991), and employees may engage in poaching (Wilkie et al., 1992). Development projects - - such as roads, railways, mines, onshore oil fields, and logging concessions - -
MANAGEMENT AND PROTECTION Elephant management and protection is more difficult in the equatorial forests than in the open habitats of eastern or southern Africa. The thick tree canopy prevents aerial surveillance. Thus one can neither monitor the numbers and distribution of live elephants nor count carcasses from the air, the increase in the ratio of dead to live elephants being one of the first signs of an upsurge in elephant poaching (Douglas-Hamilton & Burrill, 1991). This problem of surveillance is compounded by the widespread distribution of forestdwelling elephants. In other countries where elephants are restricted to certain parks or provinces the resources for surveillance and protection can be concentrated in relatively small areas. In contrast, wildlife departments in the equatorial forests are spread too thinly to be effective. Since elephants cannot be protected throughout their entire forest range, the alternative is to protect them in reserves or national parks where resources can be concentrated (Leader-Williams & Albon, 1988). However, many of the listed protected areas (IUCN 1991) exist on paper only and provide little protection for elephants. For example, Maiko NP in Zaire was found to be occupied by gold-panners and rebels (Alers et al., 1992). Each of the wildlife departments we have seen lacks staff, field equipment, vehicles, and adequate operating budgets. Many wildlife officers spend little time in the field and therefore cannot develop the professional expertise and field experience needed to make their departments effective. FUTURE THREATS TO ELEPHANTS Ivory poaching will always pose a threat because it is so difficult to monitor in the forest, but it is not the only threat. Parker and Graham (1989) have argued that the decline of elephants across the continent is not due to ivory poaching but to the conflict between elephants and expanding human populations. However, small human populations and a high rate of urbanisation result in low rural densities in central Africa (Table
Table 3. Human population statistics for the central African countries in 1983 (from World Bank, 1986); the estimates for the rural populations and their trends were calculated from data on population sizes and urbanisation rates in World Bank (1986)
Country
Cameroun CAR Congo Equatorial Guinea Gabon Zaire
Population (million)
Urban population as % of total
Density of rural population (people/km2)
% change in rural population 1965-1983
9-6 2-5 1.8 0.4 0-7 29.7
39 44 55 57 39 38
12-3 2-3 2.4 6-1 1.6 7-9
+ 17 +9 + 14 -15 -I0 + 14
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are also expanding into previously inaccessible areas. For example, the construction of a road westwards from Bangui towards Bambio in CAR, has resulted in the virtual disappearance of elephants from that area (Fay, 1991), and road construction in northern Congo stimulated ivory poaching (Fay & Agnagna, 1993). The discovery of oil in the forests of western Gabon has brought roads, pipelines, and increasing human activity to an area that was hitherto undisturbed.
DISCUSSION
Ivory poaching The field work in 1989 confirmed the earlier assessments by Douglas-Hamilton (1979) and Barnes (1987) that large-scale poaching was taking place in the equatorial forests. Many had thought that these provided a refuge for large numbers of elephants (Anon., 1984; DouglasHamilton & Douglas-Hamilton, 1992). Rather, the forest canopy obscured the situation and allowed widespread poaching to proceed largely unnoticed. Poaching has had a major impact upon the abundance of elephants in the forests of Cameroun, Congo, CAR., and Zaire. The lack of data precludes an accurate estimate of the effect on numbers, but Michelmore et al.'s (in press) model suggests the order of magnitude of the change. Among the factors contributing to the widespread ivory poaching in the forests were the price of ivory, poverty, corruption, and the availability of firearms. Poachers were stimulated by the rapid increase in the international price of ivory (Douglas-Hamilton, 1987; Barbier et al., 1990). The poverty of the rural population, and the lack of opportunities to make money by other means, made ivory a tempting source of quick income. Similarly, poorly paid officials are susceptible to bribery. As is the case elsewhere in Africa, corruption is common in central Africa (Gould, 1980; Whitaker, 1989; Legum & Doro, 1989a,b,c: Klitgaard, 1990). The role of corruption in poaching and ivory smuggling is emphasised in the reports by the field teams and the Ivory Trade Review Group consultants (Allaway, 1989a,b; De Meulenaer & Meredith, 1989; Meredith, 1989; Fay, 1991; Fay & Agnagna, 1991; Alers et al., 1992; Barnes et al., 1993). The correlation between the availability of firearms and ivory poaching described by Douglas-Hamilton (1983, 1987) was also noticed in the central African forests. Those countries where automatic weapons are easily obtained are also those where ivory poaching has been most intense (Barnes et al., 1993). Constraints on elephant management In contrast to savanna-dwelling elephants, we know very little about even the most basic aspects of forest elephant biology. There are few data on numbers, and no data from which trends can be estimated, except for Michelmore et al.'s (in press) model. Those estimates of numbers which are available must be treated with cau-
tion because they are based upon indirect survey methods (i.e. dung counts) and small sample sizes. Detailed censuses of elephant numbers and distribution should be made in each country, and then repeated at regular intervals to determine trends. Studies of elephant movements and habitat requirements are needed for planning protected areas and maintaining migration routes. The problem of crop-raiding and its prevention requires investigation. In many places in the forest it is not even clear which sub-species is present. The taxonomy of forest elephants needs to be clarified, as does the distribution and ecological relationships of the different sub-species. This ignorance of elephant biology is one of the four major constraints on the management of elephants in the forest zone. The second is the ineffectiveness of wildlife departments. The third is corruption, which renders impossible the effective management of a species producing a high-value commodity like ivory. The fourth is the general difficulty of working in the forest zone: the large areas to be covered, the difficulty and consequent high costs of access to remote forests, and the fact that the dense forest canopy prevents monitoring of elephants and poachers from the air.
Elephant conservation strategies In the short term, a moratorium on the ivory trade is needed in order for effective international control measures to be established and for wildlife departments to build themselves up to the stage where they can effectively manage their elephant populations, and develop the ability (a) to monitor the numbers, distribution, and trends of elephants, (b) to calculate hunting quotas, (c) to deal with crop-raiding elephants, (d) to control the movement of ivory within the country, and (e) across borders. In the long term, governments will need to establish national elephant plans which incorporate protected areas and controlled hunting areas within a larger landuse plan. The sparsely populated forests of Gabon, northern Congo, southeastern Cameroun, and central Zaire present the potential for preparing elephant conservation plans before the pressures of expanding human populations, agriculture, logging, and development projects become too great (McShane, 1990). Elephants are both a pest, causing damage to crops and killing people, and a resource with the potential to provide meat and ivory. These negative and positive values could possibly be reconciled by programmes allowing village people to harvest elephants on a sustainable basis (Martin, 1986). However, programmes involving the active management of elephants will fail if wildlife departments are ineffective or if corruption is widespread. ACKNOWLEDGEMENTS We thank Wildlife Conservation International, the Royal Society, and the EEC/WWF African Elephant Programme for financial support. The manuscript was
Central African forest elephant status
criticised by Karen Barnes, Iain Douglas-Hamilton, Mike Fay, and Bill Newmark. REFERENCES Alers, M. P. T., Blom, A., Sikubwabo Kiyengo, C., Masunda, T. & Barnes, R. F. W. (1992). Preliminary assessment of the status of the forest elephant in Zaire. Aft. J. Ecol., 30, 279-91. Allaway, J. (1989a). The ivory trade in Cameroun. In The ivory trade and the future of the African elephant, ed. S. Cobb. Ivory Trade Review Group, Oxford. Allaway, J. (1989b). The ivory trade in Gabon. In The ivory trade and the Jiaure of the aJbican elephant, ed. S. Cobb. Ivory Trade Review Group, Oxford. Anon. (1984). Final priorities for the action plan. In The status and conservation of Africa's rhinos and elephants, ed. D. H. M. Cumming & P. Jackson. IUCN. Gland, pp. 11-17. Anon. (1990). New evidence supports existence of pygmy elephant. Newsletter of the International Society of Cryptozoology, 9, 1 6. Barbier, E. B., Burgess, J. C., Swanson, T. M. & Pierce, D. W. (1990). Elephants, economics, and ivoo,. Earthscan Publications, London. Barnes, R. F. W. (1987). review of the status of elephants in the rain forests of central Africa. In African elephant database project. Final report, ed. A. Burrill & I. DouglasHamilton. UNEP/GRID, Nairobi, pp. 41-6. Barnes, R. F. W. (1990). Deforestation trends in tropical Africa. AJ?. J. Ecol., 28, 161-73. Barnes, R. F. W. (1993). Indirect methods for counting elephants in forest. Pachyderm, 16, 24-30. Barnes, R. F. W., Agnagna, M., Alers, M. P. T. et al. (1993). Elephants and ivory poaching in the forests of equatorial Africa: report of a field reconnaissance. Oryx, 27, 27-34. Barnes, R. F. W. & Barnes, K. L. (1992). Estimating decay rates of elephant dung piles in forest. Afr. J, Ecol., 30, 316-21. Barnes, R. F. W., Barnes, K. L., Alers, M. P. T. & Blom, A. (1991). Man determines the distribution of elephants in the rain forests of northeastern Gabon. Aft. J. Ecol., 29, 54-63. Barnes, R. F. W. & Jensen, K. L. (1987). How to count elephants in forests. IUCN African Elephant & Rhino Specialist Group Technical Bulletin, 1, 1-6. Barnes, R. F. W. & Kapela, E. B. (1991). Changes in the Ruaha elephant population caused by poaching. AJJ'. J. Ecol., 29, 289-94. Breteler, F. J. (1989). Gabon. In Floristic inventory of tropical countries: the status of plant sw'tematics, collections, and vegetation, plus recommendations for the future, ed. D. G. Campbell & H. D. Hammond. The New York Botanical Garden, New York, pp. 198-202. Carroll, R. (1986). Status of the lowland gorilla and other wildlife in the Dzanga-Sangha region of southwestern Central African Republic. Primate Conserv., 7, 38-41. Carroll R. W. (1988). Elephants of the Dzangha-Sangha dense forest of south-western Central African Republic. Pachyderm, 10, 12-15. Carroll, R. W. (1992). Central African Republic. In The conservation atlas of tropical forests: Africa, ed. J. A. Sayer, C. S. Harcourt & N. M. Collins. Macmillan, London, pp.
I 19-24. Cobb, S. (1989). The ivory trade and the future of the African elephant. Ivory Trade Review Group, Oxford. Cumming, D. H. M., Du Toit, R. F. & Stuart, S. N. (1990). African elephants and rhinos: status survey and conservation action plan. IUCN, Gland. De Meulenaer, T. & Meredith, M. (1989). The ivory trade in Zaire. In The ivory trade and the future of the african elephant, ed. S. Cobb. Ivory Trade Review Group, Oxford.
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Douglas-Hamilton, I. (1979). African elephant ivory trade study: final report. US Fish & Wildlife Service, Department of the Interior, Washington, DC (unpublished report). Douglas-Hamilton, I. (1983). Elephants hit by African arms race. Pachyderm, 2, 1I- 13. Douglas-Hamilton, I. (1987. African elephants: population trends and their causes. Oryx, 21, 11-24. Douglas-Hamilton, I. (1988). The great East African elephant disaster. Swara, 11, 8-11. Douglas-Hamilton, 1. (1989). Overview of status and trends of the African elephant. In The ivory trade and the fiaure of the African elephant, ed. S. Cobb. Ivory Trade Review Group, Oxford. Douglas-Hamilton, I. & Burrill, A. (1991). Using elephant carcass ratios to determine population trends. In African wildlife." research and management. International Council of Scientific Unions, pp. 98-105. Douglas-Hamilton, I. & Douglas-Hamilton, O. (1992). Battle Jot the elephants. Viking, New York. Doumenge, C. (1990). La conservation des ~eosvst~mes Jbrestiers du Zaire. IUCN, Cambridge. Dudley, J. P., Mensah-Ntiamoah, A. Y. & Kpelle, D. G. (1992). Forest elephants in a rainforest fragment: preliminary findings from a wildlife conservation project in southern Ghana. Air. J. Ecol., 30, 116-26. Fa, J. (1992). Equatorial Guinea. In The conservation atlas o1 tropicalJorests: A/rica, ed. J. A. Sayer, C. S. Harcourt & N. M. Collins. Macmillan, London, pp. 161-7. FAO/UNEP (1981). Tropical forest resources assessment project. /orest resources of tropical ~{/?ica. FAO/UNEP, Rome. Fay, J. M. (1991). A population survey of elephants Loxodonta africana in the forests of Central African Republic. J. Trop. Ecol., 7, 25-36. Fay, J. M. & Agnagna, M. (1991). A population survey of forest elephants Loxodonta aJricana cvclotis in northern Congo. Air. J. EcoL, 29, 177-87. Fay, J. M. Agnagna, M. (1993). Elephants and ivory in the Congo since the ban: the lull before the storm? Pachyderm, 16, 51-8. Gartlan, S. (1989). Conservation des ecosyst6mes forestiers Cameroun. IUCN, Cambridge. Gartlan, S. (1992) Cameroon. In The conservation atlas o/' tropical forests: Afriea, ed. J. A. Sayer, C. S. Harcourt & N. M. Collins. Macmillan, London, pp. 110-18. Gould, D. J. (1980). Bureacratic corruption and under development in the Third World." the case of Zaire. Pergamon Press, New York. Hecketsweiler, P. (1990). La conservation des ~cosystOmes Jbrestiers du Congo. IUCN, Cambridge. Horta, K. (1991). The last big rush for the green gold: the plundering of Cameroon's rainforests. The Ecologist, 21, 142 7. IUCN (1991). Protected areas of the world: a review ~[national systems, VoL 3. A[rotropical. IUCN, Gland. Kendrick, K. (1989). Equatorial Africa (Cameroun, People's Republic of the Congo, Central African Republic, Angola, Zaire, Rwanda and Burundi). In Floristic inventory oftrop#'a/ countries." the status of plant systematics, collections, and vegetation, plus recommendations./or the future, ed. D. G. Campbell & H. D. Hammond. The New York Botanical Garden, New York, pp. 204-16. Klitgaard, R. (1990). Tropical gangsters: one man's experience with development and decadence in deepest Africa. Basic Books, New York. Koster, S. H. & Hart, J. A. (1988). Methods of estimating ungulate populations in tropical forests. Afr. J. Ecol., 26, 117-26. Lahm, S. A. (1993). Ecology and economics of human/wildlife interaction in northeastern Gabon. PhD dissertation, New York University. Leader-Williams, N. & Albon, S. D. (1988). Allocation of resources for conservation. Nature, Lond., 336, 533-5.
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Legum, C. & Doro, M. E. (1989a). Cameroun, In Africa contemporary record." annual survey & documents 1987-88, pp. BI63-BI69. Legum, C, & Doro, M. E. (1989b). Equatorial Guinea. In Africa contemporary record; annual survey & documents 1987-88, pp. B209-B217. Legum, C. & Doro, M. E. (1989c). Zaire. In Africa contemporary record." annual survey & documents 1987~8, pp. B230-B244. Letouzey, R. (1968). Etude phytogOographique du Cameroun. Encyclopedie Biologique, LXIX, Paul Lechevalier, Paris, France. Luxmoore, R, Caldwell, J. & Hithersay, L. (1989). The volume of raw ivory entering international trade from African producing countries from 1979-1988. In The ivory trade and the future of the African elephant, ed. S. Cobb. Ivory Trade Re$iew Group, Oxford. McShane, T. O. (1990). Conservation before the crisis - - an opportunity in Gabon. Oryx, 24, 9-14. Martin, C. (1991), The rainforests of West AJrica. Birkhauser Verlag, Basel. Martin, R. B. (1986). Communal area management plan for indigenous resources (project CAMPFIRE). In Conservation and wildlife management in Africa, ed. R. H. V. Bell & E. McShane-Caluzi. US Peace Corps, Washington DC, pp. 279-95. Meredith, M. (1989). The ivory trade in Congo. In The ivory trade and the future of the African elephant, ed. S. Cobb. Ivory Trade Review Group, Oxford. Merz, G. (1981). Recherches sur la biologie de nutrition et les habitats pr~f6renc~s de l'616phant de foret Loxodonta africana cyclotis Matschie 1900. Mammalia, 45, 299-312. Merz, G. (1986). Counting elephants Loxodonta africana cyclotis in tropical rain forests with particular reference to the Tai National Park, Ivory Coast. Afr. J. Ecol., 24, 61-8. Michelmore, F., Beardsley, Barnes, R. F. W. & DouglasHamilton, I. (1989). Elephant population estimates for the central African forests. In The ivory trade and the future of the African elephant, ed. S. Cobb. Ivory Trade Review Group, Oxford. Michelmore, F., Beardsley, Barnes, R. F. W. & DouglasHamilton, I. (in press). A model illustrating the changes in forest elephant numbers caused by poaching. Afr. J. Ecol. Nicoll, M. & Langrand, O. (1986). Conservation et utilisation rationelle des kcosyst~mes forestiers du Gabon. IUCN, Gland. Noack T. (1906). Eine Zwergform des Afrikanischen Elefanten. Zool. Anzeig., 29, 631-3. N'Sosso, N. & Hecketsweiler, P. (1992). Congo. In The conservation atlas oJ"tropical Jbrests." Africa, ed. J. A. Sayer, C. S. Harcourt & N. M. Collins. Macmillan, London, pp. 125-32. Parker, I. S. C. (1979). The ivory trade. US Fish & Wildlife
Service, Department of the Interior, Washington, DC (unpublished report). Parker, I. S. C. & Graham, A. D. (1989). Elephant decline: downward trends in African elephant distribution and numbers, Part I. Int. J. Environ. Stud., 34, 287-305. Pfeffer, P. (1960). Sur la validit~ de formes naines de l'~16phant d'Afrique. Mammalia, 24, 556-76. Pilgram, T. & Western, D. (1986). Inferring the sex and age of African elephants from tusk measurements. Biol. Conserv., 36, 39-52. Poole, J. H. (1989). The effects of poaching on the age structures and social and reproductive patterns of selected east African elephant populations. In The ivory trade and the future of African Elephant, ed. S. Cobb. Ivory Trade Review Group, Oxford. Reitsma, J. M. (1988). Forest vegetation of Gabon. The Tropenbos Foundation, Ede, Netherlands. Roth, H. H. & Douglas-Hamilton, I. (1991). Distribution and status of elephants in West Africa. Mammalia, 55, 489-527. Sayer, J. A. (1992). Zaire. In The conservation atlas of tropical Jbrests: Africa, ed. J. A. Sayer, C. S. Harcourt & N. M. Collins. Macmillan, London, pp. 272 82. Short, J. C. (1983). Density and seasonal movements of the forest elephant Loxodonta afrieana cyclotis Matschie in Bia National Park~ Ghana. Afr. J. Ecol., 21, 175-84. Stromayer, K. A. K. & Ekobo, A. (1992). The distribution and number of forest dwelling elephants in extreme southeastern Cameroun. Pachyderm, 15, 9-14. Tchamba, M. (1992). Defaecation by the African forest elephant Loxodonta africana cyclotis in the Santchou Reserve, Cameroun. Mammalia, 56, 155-8. Tutin, C. E. G. (1992) Gabon. In The conservation atlas of tropical Forests: AJrica, ed. J. A. Sayer, C. S. Harcourt & N. M. Collins. Macmillan, London, pp. 168-74. Tutin, C. E. G. & Fernandez, M. (1984). Nationwide census of gorilla Gorilla g. gorilla and chimpanzee Pan t. troglodytes populations in Gabon. Amer. J. Primatol., 6, 313-16. Western, D. (1986). The pygmy elephant: a myth and a mystery. Pachyderm, 7, 4-5. Western, D. (1990). Is the tide turning for elephants and rhinos? Pachyderm, 13, 2 4 . Whitaker, J. S. (1988). How can Africa survive? Harper & Row, New York. White, F. (1983). The vegetation of Africa. UNESCO, Paris Wilkie, D. S., Sidle, J. G. & Boundzanga, G. C. (1992). Mechanized logging, market hunting, and a bank loan in Congo. Conserv. Biol., 6, 570-80. Wilks, C. (1990). La Conservation des Ocosyst~mesforestiers du Gabon. IUCN, Cambridge. World Bank (1986). Population growth and policies in sub-saharan Africa. World Bank, Washington DC. WRI (1992). Worm resources 1992-93. Oxford University Press, New York.
ELSEVIER
0006-3207(94)00014-X
Elsevier Science Limited Printed in Great Britain 0006-3207/95/$9.50
A REVIEW OF THE STATUS OF FOREST ELEPHANTS L O X O D O N T A AFRICANA IN CENTRAL AFRICA R. F. W. Barnes,* A. Blom & M. P. T. Alers Wildlife Conservation Society, The International Wildlife Conservation Park. Bronx, New York 10460-1099, USA (Received 5 October 1993; revised version received 5 January 1994; accepted 9 January 1994)
Abstract The status of elephants Loxodonta africana in the central African forests in 1989 is reviewed These elephants accounted for about one-third of the continental total. However, there are few data on numbers, for only one of the six countries in the region has been censused. The estimates for the other countries came from a limited set of dung-counts or a model based on those dung-counts. Poaching for ivory was widespread in four of the six countries, but the lack of census data makes it difficult to assess its impact. The distribution of elephants was determined by the intensity of poaching, the distribution of roads and settlements, and the distribution of secondary forest. Ivory exports from central Africa accounted for about one-third of the continental total in 1979-1988, but this included an unknown proportion of ivory from savanna elephants. While poaching is the most urgent short-term threat, the problems posed by expanding human activities in the forest zone need to be addressed by national elephant conservation plans. The main constraints on elephant management are the general lack of information on basic forest elephant biology, the weakness of government wildlife departments, corruption, the vast areas to be covered, the difficulty of access to remote forests, and the impossibility of surveillance from the air.
In the 1970s and 1980s, a wave of ivory poaching swept across Africa (Douglas-Hamilton, 1987, 1988; Cobb, 1989). Sixty percent of the ivory exported from Africa came from the equatorial forests (Parker, 1979), yet no data were available on forest elephant numbers, trends, or distribution. Accordingly, Wildlife Conservation International (now re-named NYZS The Wildlife Conservation Society) organised a programme of field work to establish the status of elephants in the central African forests. In this paper we draw together the results from six countries, and combine them with the findings of the Ivory Trade Review Group (Cobb, 1989) to present an overview of the elephant situation at the end of 1989 in the equatorial forests of central Africa. Late 1989 is an appropriate point in time because four of the six countries were surveyed that year (Fay, 1991; Fay & Agnagna, 1991; Alers et al., 1992; Barnes et al., 1993), and in January 1990 the CITES ban on the international ivory trade came into effect (Western, 1990).
THE EQUATORIAL FORESTS The forests of central Africa cover about 1.75 million km 2 (FAO/UNEP, 1981) in the centre of the continent (Fig. 1). They include parts of six countries: Cameroun, Central African Republic (CAR), Congo, Equatorial Guinea, Gabon, and Zaire. White (1983) classifies the central African forests as Guinea-Congolian rain forest and gives a general description. Overviews of the status of the forests of the separate countries are given by Letouzey (1968), Reitsma (1988), Breteler (1989), Gartlan (1989, 1992), Kendrick (1989), Doumenge (1990), Hecketsweiler (1990), Wilks (1990), Carroll (1992), Fa (1992), N'Sosso & Hecketsweiler (1992), Sayer (1992), and Yutin (1992).
Keywords." Central Africa, forests, elephants. INTRODUCTION During the last three decades, the elephant Loxodonta africana has been one of the most intensively studied animals on the African continent. However, most research has focused on the elephants of the relatively open habitats of eastern and southern Africa. Those in the dense forests of central Africa have been ignored by the majority of biologists. Even the most basic information, such as the size of the elephant population in the equatorial forests, was for a long time the subject of speculation (Anon, 1984; Douglas-Hamilton & Douglas- Hamilton, 1992).
FOREST ELEPHANTS Two sub-species of African elephant are recognised. In west Africa, Loxodonta africana cyclotis is found in the forest while L. a. africana occurs in the open habitats, with intermediate forms seen in transition zones (Roth & Douglas-Hamilton, 1991). In central Africa the situation is less clear cut and both sub-species, and hybrids, occur in the forest zone (Western, 1986; Carroll,
*To whom correspondence should be addressed at: Department of Biology 0116, University of California at San Diego, La Jolla, California 92093-0116, USA 125
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R. F. W. Barnes, A. Blom, M. P. T. Alers
It pS | I
•
I
•
I
t
!
Fig. 1. The rain forest countries of central Africa. 1, Cameroun; 2, Equatorial Guinea; 3, Gabon; 4, Central African Republic (CAR); 5, Congo; 6, Zaire. International f r o n t i e r ; - - - - Boundary of rain forest; Atlantic Coast. 1988: Barnes et al., 1993; Lahm, 1993). Because elephants are difficult to see in forest, the distributions of the two sub-species are not known. In some forests both are found, while elsewhere only one occurs. Stories of the existence of a pygmy elephant (L. a. pumilio), originally described by Noack (1906), have been explained as juvenile elephants (Pfeffer, 1960; Western, 1986). However, Anon. (1990) claims that much of the evidence in favour of the pygmy elephant has been overlooked. ELEPHANT NUMBERS AND DISTRIBUTION
The dense canopy and thick undergrowth of the forest zone makes direct counts of large mammals difficult, whether from the air or the ground. Instead, forestdwelling mammals are normally censused by indirect methods, such as counts of dung or nests (Short 1983; Tutin & Fernandez, 1984; Merz 1986; Barnes & Jensen, 1987; Koster & Hart, 1988; Barnes et al., 1991; Barnes, 1993). The most intensive elephant census work has been conducted in Gabon. In northeastern Gabon there was a strong correlation between elephant density and perpendicular distance from the nearest road or village (Barnes et al., t991). At the time of that survey there was little ivory poaching, and so the low elephant
densities close to villages and roads were the result of elephants avoiding human activity. The gradient of elephant density was modified by the presence of secondary forest, which is the result of human settlement and agriculture in the past, and is the preferred habitat for forest elephants (Merz, 1981; Barnes et al., 1991). The distance from the nearest road and the percentage of transects covered by secondary forest explained three-quarters of the variance in elephant numbers in northeastern Gabon (Barnes et al., 1991). The highest elephant densities were found in remote forests which had been inhabited by shifting cultivators until the 1950s or 1960s. The abandoned villages and plantations left a mosaic of primary and secondary forest favoured by elephants (Barnes et al., 1991). These large expanses of forest, now undisturbed by human activity, explain the high estimates of elephant numbers for Gabon. A stratified sample census based on dung-counts gave an estimate of 62,000 with 95% CL of +20,000 (R. F. W. Barnes, A. Blom, M. P. T. Alers & K. L, Barnes, unpublished data). Michelmore et al.'s (in press) figure of 55,000 may be an under-estimate because it is based upon White's (1983) vegetation map which underrepresents Gabon's forest area compared with other maps. In 1989 a reconnaissance was made of the forests of four countries (Cameroun, CAR, Congo, and Zaire), in order to obtain preliminary data on the status of elephants
Central A f r i c a n . & r e s t elephant status
Table 1. Estimates of the numbers of elephants remaining in central Africa
Country
Cameroun CAR Congo Equatorial Guinea Gabon Zaire Total
Estimated number Estimated combined of forest elephants number of forest in 1989" and savanna elephants in 1989~ 12,000 2,000 31,000 400 55,000 72,000
18,000 23,000 32,000 400 60,000 97,000
172,400
230,400
"Calculated by Michelmore et al. (in press). hNumbers of savanna-dwellingelephants calculated from data in Douglas-Hamilton (1989). as a basis for planning systematic surveys in the future (Fay, 1991; Fay & Agnagna, 1991; Alers et al., 1992; Barnes et al., 1993). Elephant density gradients similar to that in Gabon were found in CAR, Congo, and Zaire (Fay, 1991; Fay & Agnagna, 1991; Alers et al., 1992. Since these gradients in relation to human disturbance appear to be a general rule governing elephant distribution in the sparsely-populated forests of central Africa, Michelmore et al. (in press) incorporated them into a model for estimating forest elephant numbers (Table 1). The forests of northern Congo still harboured a large population of elephants in 1989, despite evidence of considerable poaching activity (Fay & Agnagna, 1991). Elephant densities were estimated to be higher in this area than anywhere else in the forest zone with the exception of southeastern Cameroun (Fay & Agnagna, 1991). The abundance of elephants can be explained by the marked gradient of elephant density in relation to human settlements and the large expanses of uninhabited forest (Fay & Agnagna, 1991). In contrast, the forests of southern Congo were heavily settled and have long been disturbed by logging and heavy hunting. As a consequence, the elephant population was fragmented into four sub-populations (M. Agnagna, R. F. W. Barnes, & M. Ipandza, unpublished data). The forest elephant model gave an estimate of 31,000 for Congo (Table 1). This is probably an over-estimate because it does not account for elephants leaving the swamp forests of northeastern Congo in the wet season (Fay & Agnagna, 1991). Therefore the average density in the swamps over the year is probably lower than that estimated by the model. Large parts of Cameroun's southwestern and southcentral forests are densely settled and elephants remain only in isolated pockets (Barnes et al., 1993). An exception is the Korup area close to the Nigerian frontier. It is in the sparsely inhabited forests of the south-east that most of Cameroun's elephants are found. Stromayer and Ekobo (1992) recorded very high densities in the extreme southeastern forests, indicating a much larger forest elephant population for Cameroun than the 12,000 estimated by Michelmore et al. (in press) (Table 1).
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Forest covers only a small part of CAR, in the southwest and in the southeast. Carroll (1986) and Fay (1991) reported high elephant densities in the extreme southwestern forests, which lie adjacent to the frontiers with Cameroun and Congo. However, few signs of elephants were seen in the eastern part of the southwestern block, where there was a higher human density (Fay, 1991). Elephants were found to be abundant in the southeastern forest block of CAR (Fay, 1991). This was a surprising result because of the reports of heavy poaching there. Elephants may have moved into those forests to avoid the even heavier poaching outside (Fay, 1991). The numbers of elephants in CAR's savanna zone had been cut by 80% between 1976 and 1985 (DouglasHamilton, 1987), and Fay (1991) concluded that a disproportionately high number of CAR's remaining elephants, about 6,000, were to be found in the forest zone. The model gave an estimate of only 2,000 forest elephants for CAR (Table 1). The difference between the two figures is because higher elephant densities occurred in the southeast and extreme southwest (Carrol, 1986; Fay, 1991) than predicted by the model. Only a few hundred elephants are thought to remain on the mainland of Equatorial Guinea, which is a small and densely populated country (Table 1). They are found in the southern part of the country (M. P. T. Alers &Blom, unpublished data). The remote forests of Zaire, covering about 1 million km 2, have long been thought to harbour a large elephant population (Anon., 1984; Douglas-Hamilton & Douglas-Hamilton, 1992). The collapse of the road infrastructure since Independence (Whitaker, 1988) should, according to Michelmore et al.'s (in press) model, have benefited elephants. However, there are reports of large numbers being killed during the last 30 years (Barnes, 1987). Alers et al. (1992) found evidence of heavy ivory poaching in the forest zone. Poachers used the extensive river system to hunt elephants in the remotest forests, and elephants appear to have been eradicated from large areas of forest (Alers et al., 1992). The numbers of elephants remaining in the forests of Zaire have been calculated by Michelmore et al. (in press) to be 72,000 (Table l). However, this does not account for the unknown area of forest from which elephants have been eliminated. Alers et al. (1992) made an approximate estimate of elephant numbers by using the density estimates from their study areas and assuming that they exist at very low density (0.01 per km ~) over the rest of the forest zone. This gave a figure of 64,000 elephants. These studies have shown the overwhelming importance of human activities in determining elephant abundance in the central African forests. Humans influence elephant densities in three ways. First, elephants avoid sources of human disturbance such as roads and villages, even in the absence of ivory poaching. Second, poaching reduces elephant numbers. This is illustrated by the curve relating elephants to roads, which was shallower for those countries with heavy poaching compared with Gabon, where there was little poaching (MicheImore
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R. F. W. Barnes, A. Blom, M. P. T. Alers
et al., in press). Thirdly, elephants' preferred habitat.
secondary forest, is created by human activity. The first two factors have a negative effect on elephant abundance, while the third has a positive effect. Thus the highest densities of elephants were found in the remote sparsely-populated zone spanning the corners of four adjacent countries: northeastern Gabon, southeastern Cameroun, northern Congo, and southwestern CAR (Fig. 1). This zone represents the most important single area for forest elephants on the continent. Altogether, about 170,000 forest elephants were estimated by Michelmore et al. (in press) to remain in the central African forests (Table 1). This figure is lower than the estimate of 214,000 presented by an earlier version of the same model (Michelmore et al., 1989), largely because of new information on defecation and decay rates (Tchamba 1992; Barnes & Barnes, 1992). Adding the numbers of savanna-dwelling elephants (calculated from the tables in Douglas-Hamilton, 1989) gives a total central African population of 230,000 (Table 1). Douglas-Hamilton (1989) estimated the numbers of elephants in eastern, southern, and western Africa to be 110,000, 204,000, and 19,000 respectively. Therefore, based on his figures and those of Michelmore et al. (in press), in 1989 the central African forest population accounted for about one third of the continental total of 563,000.
IVORY P O A C H I N G Effect of ivory poaching on numbers
The impact of ivory poaching on elephants in the central African forests has been described in qualitative terms by Barnes (1987), Barnes et al. (1991), Fay (1991), Fay & Agnagna (1991), Alers et al. (1992) and Barnes et al. (1993). Large-scale commercial poaching has been especially severe in Zaire, Congo, and Cameroun, while Gabon seems to have escaped. No census work was done before the poaching upsurge, and the recent reconnaissance surveys covered only a very small part of the elephants' range. Therefore it is difficult to estimate directly the impact on elephant numbers caused by poaching. However, Michelmore et al. (1989) made an indirect assessment by comparing the present distribution of elephants with a model of the distribution before the poaching upsurge. This suggested that ivory poaching had reduced forest elephant numbers by over 40%. Evidence from the ivory trade
A large proportion of the ivory exported from Africa comes from elephants killed illegally (Luxmoore et al., 1989; Cumming et al., 1990). Large quantities of ivory have been smuggled from one country to another within central Africa (Douglas-Hamilton, 1979; Allaway, 1989a, b; De Meulenaer & Meredith, 1989; Meredith, 1989; Fay & Agnagna, 1993). Much ivory has also been exported illegally from central Africa. For example, most of the ivory exported from Zaire was smuggled into neighboring countries or flown out
illicitly (Douglas-Hamilton, 1979; De Meulenaer & Meredith 1989; Fay & Agnagna, 1993). Between 1979 and 1988, 955 tonnes of ivory were exported from Congo (Luxmoore et al., 1989), but only 540 tonnes (or 57%) appear in Congolese government records (Meredith, 1989). The rest was presumably smuggled. Even less was recorded in Cameroun and Gabon. The Camerounian customs recorded only 2.5% of the ivory exported from Cameroun in 1979, 1980, 1982, 1985 and 1988 (Allaway, 1989a). The Gabonese customs recorded less than 1% of the ivory exported from Gabon between 1983 and 1988 (Allaway, 1989b). Luxmoore et al. (1989) used the records of the importing countries to estimate the volume of ivory exported (both legally and illegally) from each African country. The largest quantities were exported by CAR, Congo, and Zaire (Table 2). The figure for Zaire is almost certainly an under-estimate because much ivory was smuggled out and exported from its neighbours (De Meulenaer & Meredith, 1989; Fay & Agnagna, 1993). The volumes in Table 2 represent 36% of the maximum continental total estimated by Luxmoore et al. (1989) for that decade. However, these figures include tusks from elephants killed in both the forest and savanna zones, and the proportion coming from each zone is unknown. Thus although the central African countries made a significant contribution to the continental ivory trade in 1979-1988, one cannot estimate the overall contribution of central African forest elephants. In East Africa poaching has distorted the age structure of elephant populations as well as reducing numbers (Poole, 1989; Barnes & Kapela, 1991). Changes in tusk weights can sometimes be used to deduce changes in age structure (Barnes & Kapela, 1991), because there is a relationship between tusk weight and age (Pilgram & Western, 1989). However, in central Africa tusks are smuggled from one country to another and large tusks are often selected out and smuggled along one route leaving the smaller tusks to pass along another (De Meulenaer & Meredith, 1989). Thus the distribution of tusk weights recorded for each country does not reflect the original weight distribution of tusks from elephants killed in that country. Further, the records do not distinguish between tusks from L. a. cyclotis and L. a. africana, nor between males and females, Since the Table 2. Quantities of raw ivory exported from the central African countries between 1979 and 1988 (from Luxmoore et al., 1989)
Country
Cameroon CAR Congo Equatorial Guinea Gabon Zaire Total
Total ivory exported 1979 1988 (tonnes) 37 1,098 955 No data 27 705 2,822
Central African forest elephant status relationship between tusk weight and age is different for the two sub-species, and differs between sexes for each sub-species, an analysis of age structure is impossible.
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3). Furthermore, in Gabon and Equatorial Guinea human densities have been declining because the exodus to the towns exceeded the birth rate (Table 3). Thus the conflicts between humans and elephants may not have been as serious as in the more densely populated parts of the continent. On the other hand, in Gabon the rural exodus will reverse because of changing economic circumstances (Lahm, 1993), and in general throughout the region human populations are increasing (World Bank, 1986). Elephants have been displaced or eradicated by expanding villages and agriculture in the southwestern and central parts of the forests of Cameroun, and from the forests of southern Congo and CAR, and in Zaire from the environs of Kisangani and the heavily populated edges of the forest block. The further spread of villages and agriculture will inevitably increase competition between men and elephants for land in the forest zone. This will be exacerbated by deforestation. At present the rate of deforestation in central Africa is low (FAO/UNEP, 1981), but it is accelerating (Barnes, 1990; WRI, 1992). The decrease in forest combined with the increasing human population will cause a rapid decline in per capita forest resources (Barnes, 1990). This will mean less room for elephants. At the same time the forests will be fragmented, as in west Africa (Martin, 1991; Roth & Douglas-Hamilton, 1991). As each large block of forest is broken into smaller parcels, elephants will become more vulnerable to human disturbance. Logging is a major industry in central Africa and is spreading through the forests. For example, logging companies are moving into the forests of southeastern Cameroun, northern Congo, central Gabon, and central Zaire (Nicoll & Langrand, 1986, Doumenge, 1990; Horta, 1991; Tutin, 1992; Wilkie et al., 1992). In Gabon the area of undisturbed forest is expected to decline from 82,000 km 2 in 1986 to between 44,000 and 59,000 km 2 in 1997 as a result of the expansion of the logging industry (Nicoll & Langrand, 196). Logging can have a positive effect on elephants by creating patches of secondary vegetation favoured by elephants (Dudley et al., 1992); but it can also have a negative impact, because the new roads provide poachers with access to remote forests (e.g. Fay & Agnagna, 1991), and employees may engage in poaching (Wilkie et al., 1992). Development projects - - such as roads, railways, mines, onshore oil fields, and logging concessions - -
MANAGEMENT AND PROTECTION Elephant management and protection is more difficult in the equatorial forests than in the open habitats of eastern or southern Africa. The thick tree canopy prevents aerial surveillance. Thus one can neither monitor the numbers and distribution of live elephants nor count carcasses from the air, the increase in the ratio of dead to live elephants being one of the first signs of an upsurge in elephant poaching (Douglas-Hamilton & Burrill, 1991). This problem of surveillance is compounded by the widespread distribution of forestdwelling elephants. In other countries where elephants are restricted to certain parks or provinces the resources for surveillance and protection can be concentrated in relatively small areas. In contrast, wildlife departments in the equatorial forests are spread too thinly to be effective. Since elephants cannot be protected throughout their entire forest range, the alternative is to protect them in reserves or national parks where resources can be concentrated (Leader-Williams & Albon, 1988). However, many of the listed protected areas (IUCN 1991) exist on paper only and provide little protection for elephants. For example, Maiko NP in Zaire was found to be occupied by gold-panners and rebels (Alers et al., 1992). Each of the wildlife departments we have seen lacks staff, field equipment, vehicles, and adequate operating budgets. Many wildlife officers spend little time in the field and therefore cannot develop the professional expertise and field experience needed to make their departments effective. FUTURE THREATS TO ELEPHANTS Ivory poaching will always pose a threat because it is so difficult to monitor in the forest, but it is not the only threat. Parker and Graham (1989) have argued that the decline of elephants across the continent is not due to ivory poaching but to the conflict between elephants and expanding human populations. However, small human populations and a high rate of urbanisation result in low rural densities in central Africa (Table
Table 3. Human population statistics for the central African countries in 1983 (from World Bank, 1986); the estimates for the rural populations and their trends were calculated from data on population sizes and urbanisation rates in World Bank (1986)
Country
Cameroun CAR Congo Equatorial Guinea Gabon Zaire
Population (million)
Urban population as % of total
Density of rural population (people/km2)
% change in rural population 1965-1983
9-6 2-5 1.8 0.4 0-7 29.7
39 44 55 57 39 38
12-3 2-3 2.4 6-1 1.6 7-9
+ 17 +9 + 14 -15 -I0 + 14
130
R. F. W. Barnes, A. Blom, M. P. T. Alers
are also expanding into previously inaccessible areas. For example, the construction of a road westwards from Bangui towards Bambio in CAR, has resulted in the virtual disappearance of elephants from that area (Fay, 1991), and road construction in northern Congo stimulated ivory poaching (Fay & Agnagna, 1993). The discovery of oil in the forests of western Gabon has brought roads, pipelines, and increasing human activity to an area that was hitherto undisturbed.
DISCUSSION
Ivory poaching The field work in 1989 confirmed the earlier assessments by Douglas-Hamilton (1979) and Barnes (1987) that large-scale poaching was taking place in the equatorial forests. Many had thought that these provided a refuge for large numbers of elephants (Anon., 1984; DouglasHamilton & Douglas-Hamilton, 1992). Rather, the forest canopy obscured the situation and allowed widespread poaching to proceed largely unnoticed. Poaching has had a major impact upon the abundance of elephants in the forests of Cameroun, Congo, CAR., and Zaire. The lack of data precludes an accurate estimate of the effect on numbers, but Michelmore et al.'s (in press) model suggests the order of magnitude of the change. Among the factors contributing to the widespread ivory poaching in the forests were the price of ivory, poverty, corruption, and the availability of firearms. Poachers were stimulated by the rapid increase in the international price of ivory (Douglas-Hamilton, 1987; Barbier et al., 1990). The poverty of the rural population, and the lack of opportunities to make money by other means, made ivory a tempting source of quick income. Similarly, poorly paid officials are susceptible to bribery. As is the case elsewhere in Africa, corruption is common in central Africa (Gould, 1980; Whitaker, 1989; Legum & Doro, 1989a,b,c: Klitgaard, 1990). The role of corruption in poaching and ivory smuggling is emphasised in the reports by the field teams and the Ivory Trade Review Group consultants (Allaway, 1989a,b; De Meulenaer & Meredith, 1989; Meredith, 1989; Fay, 1991; Fay & Agnagna, 1991; Alers et al., 1992; Barnes et al., 1993). The correlation between the availability of firearms and ivory poaching described by Douglas-Hamilton (1983, 1987) was also noticed in the central African forests. Those countries where automatic weapons are easily obtained are also those where ivory poaching has been most intense (Barnes et al., 1993). Constraints on elephant management In contrast to savanna-dwelling elephants, we know very little about even the most basic aspects of forest elephant biology. There are few data on numbers, and no data from which trends can be estimated, except for Michelmore et al.'s (in press) model. Those estimates of numbers which are available must be treated with cau-
tion because they are based upon indirect survey methods (i.e. dung counts) and small sample sizes. Detailed censuses of elephant numbers and distribution should be made in each country, and then repeated at regular intervals to determine trends. Studies of elephant movements and habitat requirements are needed for planning protected areas and maintaining migration routes. The problem of crop-raiding and its prevention requires investigation. In many places in the forest it is not even clear which sub-species is present. The taxonomy of forest elephants needs to be clarified, as does the distribution and ecological relationships of the different sub-species. This ignorance of elephant biology is one of the four major constraints on the management of elephants in the forest zone. The second is the ineffectiveness of wildlife departments. The third is corruption, which renders impossible the effective management of a species producing a high-value commodity like ivory. The fourth is the general difficulty of working in the forest zone: the large areas to be covered, the difficulty and consequent high costs of access to remote forests, and the fact that the dense forest canopy prevents monitoring of elephants and poachers from the air.
Elephant conservation strategies In the short term, a moratorium on the ivory trade is needed in order for effective international control measures to be established and for wildlife departments to build themselves up to the stage where they can effectively manage their elephant populations, and develop the ability (a) to monitor the numbers, distribution, and trends of elephants, (b) to calculate hunting quotas, (c) to deal with crop-raiding elephants, (d) to control the movement of ivory within the country, and (e) across borders. In the long term, governments will need to establish national elephant plans which incorporate protected areas and controlled hunting areas within a larger landuse plan. The sparsely populated forests of Gabon, northern Congo, southeastern Cameroun, and central Zaire present the potential for preparing elephant conservation plans before the pressures of expanding human populations, agriculture, logging, and development projects become too great (McShane, 1990). Elephants are both a pest, causing damage to crops and killing people, and a resource with the potential to provide meat and ivory. These negative and positive values could possibly be reconciled by programmes allowing village people to harvest elephants on a sustainable basis (Martin, 1986). However, programmes involving the active management of elephants will fail if wildlife departments are ineffective or if corruption is widespread. ACKNOWLEDGEMENTS We thank Wildlife Conservation International, the Royal Society, and the EEC/WWF African Elephant Programme for financial support. The manuscript was
Central African forest elephant status
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