population numbering 10-20.
on Mwabvi GR in Malawi, just over the border. Mwabvi Game Reserve contains 6 or 7 black rhino. By itself the rhino cannot be considered a viable population, although numbers must have been low for a period of more than 60 years. The extension area of M
Before the people were removed from the old extension area in 1975, this corridor was frequently hunted for rhino, which has probably continued at a low scale (during this survey, a 4-year-old female was found killed by poachers south of Nyantoko hill, while another older skeleton (2 to 3 years) was found west of Nyantoko hill, presumably more skeletons can be found in this region). Parker (1976) found it rather strange that no rhino bones were ever discovered in the Reserve. However, a simple calculation will show that intensive patrolling is needed to discover the remains of a rhino that died a natural death in a population of only 7 animals with a lifespan of 30 years. This means that every 4.3 years one rhino dies a natural death, of which the bones remain for perhaps a couple of years. Thus every other two years the remains of only one rhino - that most likely died in the thicker vegetation can be discovered. The remains of some rhino that died a natural death and of those that were killed by poachers have only recently been discovered, firstly because the thickets are never patrolled and secondly because the patrols that are carried out always follow the same tracks. Illegal activity is the main factor why animal numbers in general have been kept low in the Reserve. Numerous bush-fence traps were found around Nyantoko hill, in Ntaya Thumba thicket and along the Mwabvi and Thangadzi rivers. Within 15 minutes, 10 bush-fences including snares were removed around Dayelo waterhole. Gunshots of muzzle-loaders and shotguns were heard frequently, while the remains of two rhino, killed by poachers were found around Nyantoko hill. It is obvious that the patrol activity of the game scouts is low, while during the patrols that are carried out they seem to almost completely fail to enforce the law. Their poor morale can be understood from the following factors: i) Mwabvi's unstable political climate, ii) persistent doubt on how to handle law breakers in the extension area, iii) poor discipline due to lack of supervision, iv) unpopularity among the local people who seem to frighten them and, v) time spent on collecting food outside the Reserve.
Survey Sep-Oct 1983, late dry season. Information was collected on foot, by covering a number of parallel transects from north to south and east to west at 1 km intervals. Each transect was covered by author, a game scout and a carrier. This gave sample intensity of ca. 11%. All signs of rhino were noted and/or measured. About 6-7 rhinos live in the reserve.
The status of rhino in Kasungu is rather stable, partly as a result of a properly functioning anti-poaching force and a well run research unit and partly due to low numbers in combination with dense vegetation.
Mwabvi is an important conservation area, firstly because it contains some of the last Malawi rhino, secondly because it contains the rare Nyala and Sable antelope, thirdly because it forms part of the extensive home ranges of several packs of African wild hunting dog and fourthly because it is a major water-catchment area. Most of the Reserve is not suitable for cultivation, while the presence of the tse-tse fly and the water shortage during the dry season also restrict human habitation. The following management recommendations should be considered: 1. The game scouts should be transferred to other conservation areas in Malawi and the Reserve re-staffed. 2. A game ranger should be based at Mwabvi camp. He should be provided with housing. 3 The number of game scouts should be increased by at least one per camp. In this way one scout can be off to collect food, while the other two are on patrol. if possible, more scouts should be based at Mwabvi camp as it is situated in the centre of the rhino area. 4. The scouts should be provided with sturdy bicycles. 5. Patrols should not be carried out following fixed routes, and should include the thicket areas. Patrols should be made daily. 6. Carriers working for the Department of National Parks and Wildlife and living in the villages of the extension area should be discharged, as all law enforcement activities are directly passed on to the hunters in these communities. 7. The Department should organise food transport into the Reserve every fortnight or at least once a month at pay-day. 8. If the extension area is not administered by the Department of National Parks and Wildlife, the original Reserve should be increased by 22 kmy , altering the boundary in those places where the rhino distribution overlaps the old extension. The present pattern of human habitation can thus, be maintained. 9. Depending under whose administrative responsibility the extension area comes, a firewood cutting scheme should be proposed to prevent excessive tree clearing. This would reduce the erosion of the lower elevations of the valley. 10. The Department should immediately look into development of fuel supplies for the rapidly expanding population of the Lower Shire vallev. The possibility of using the indigenous woodlands of both the extension area of Lengwe and Mwabvi should be consid- ered. 11. The Department should carry out research as to the effect of early burning on the food availability for rhino and other browsers in the Reserve. Of particular interest would be a study of food competition between Nyala and rhino. 12. The infrastructure of the Reserve should be developed to provide access for tourists and law enforcement activities. 13. Translocation of the Mwabvi rhino should never be considered. Firstly because the operation would be too costly, giving the density of the vegetation and shyness of the ani- mals, secondly, because numbers of rhino are too low to start a viable new population and thirdly, because at the same expense and with similar veterinary difficulties fresh stock could be introduced somewhere else in Malawi from areas like the Luangwa vallev in Zambia.
Mwabvi Game Reserve contains 6 - 7 black rhino, occupying an area of 52 kmy , covering 37 kmy of the original Reserve and 15 kmy of the extensions area. By itself the rhino cannot be considered a viable population, although numbers must have been low for a period of more than 60 years. The extension area of Mwabvi Game Reserve borders on a vast wilderness area in Mozambique. It is most likely that several rhino occupying eastern Tete District have home ranges overlapping the international border into Malawi. During the dry season, these rhino may be restricted to their range in Mozambique, as the closest available water from the international border is at Mwabvi camp. If one of the rhino occupying Mwabvi or eastern Tete District, with home ranges overlapping Mwabvi area, is killed by poachers, immigration of rhino from Zambezi area follows. Hence, the Mwabvi rhino has been kept a viable subpopulation through exchange of genetical material with the metapopulation in Mozambique.
The 6 or 7 rhino occupy an area of 52 km? , giving a density of 0.12 to 0.14/ km? . This compares with 0.32/ km? in Ngorongoro, 0.16/ km? in Olduvai Gorge, Tanzania (Goddard, 1967), 0.32/ km? in Tsavo National Park, Kenya (Goddard, 1969), 0.41/ km? in Luangwa valley, Zambia (Caughley, 1973), 0.14/ km? in Masai Mara, Kenya (Mukinya, 1973) and 0.05/ km? on the Serengeti plains in Tanzania (Frame, 1980). On account of differences in the vegetation structure, none of these areas are directly comparable. The rhino density in Masai Mara is similar to that of Mwabvi. However, the vegetation of Masai Mara consists of short grasslands, interrupted by stretches of riverine vegetation, generally containing low densities of the browsing black rhino. Olduvai Gorge also has a similar rhino density as Mwabvi. The vegetation is mainly Acacia and Coinmiphora, thornbush, roughly corresponding with the thicket vegetation in Mwabvi. The water supply is identical to that of Mwabvi, widely distributed and sparse during the dry season. As noted earlier, it is most likely that the water availability in Mwabvi is one of the main factors contributing to large home ranges, hence low rhino densities. Parker (1967) estimated that one would expect Mwabvi Reserve (351 km? ) to contain 140 rhino, based on comparison with densities of rhino in the Luangwa valley, Zambia (Caughley, 1973). This is most unlikely, firstly because one year before Parker surveyed the Reserve, the extension area was still occupied by a large number of people, reducing the available rhino area to the size of the original Reserve (131 km? ). Secondly, poaching has always limited the available area for rhino within the original Reserve, which may be the main reason that rhino spend most of their time in the thicket vegetation. Thirdly, during the latter part of the dry season, the food availability for rhino is limited to mainly woody browse, imposing a nutritional constraint, upon their expansion. Parker (1967) suggested that the early burning policy is responsible for a possible nutritional constraint. However, the thicket vegetation does not bum at all, while most of the mopane woodland hardly burns because the shallow rooting system of the trees results in a low grass biomass. Fourthly, as mentioned before, the scarcity of water during most of the dry season may well be another factor contributing to low densities of rhino.
Reasons for low numbers: 1. Human disturbance in the form of illegal hunting and trespassing. Both act through decreasing the habitat available, compressing the rhino in the dense cover of the thicket vegetation and reducing numbers by direct killing of animals. During Parker's survey (1976), I estimate that there were presumably at least 10 rhino in Mwabvi. This means that the aerial survey result was low by at least a factor of 2.5. 2. Water availability during most of the dry season is restricted to a small number of permanent waterholes of which those that are easily available are situated in an area of about 1 kmy. 3. Food availability during the latter part of the dry season is restricted to mainly woody browse. In addition, early dry season burning may even further reduce food availability for rhino during this time of year. 4. Possible predation of young rhino by lions.
Situated in the lower Shire valley in Southern Malawi, between 17.11 and 17.23 S, and 34.58 and 35.07 E.
The footprint and droppings method were not suitable for accurately determining the home ranges of the individual animals, firstly because no footprints could be found in areas with a rocky soil texture and, secondly because not enough boli of the various animals were found of which the circumference could be measured. The year-round home ranges of rhinos 1 to 3 can be roughly estimated as being 23 to 28 km? while rhino 4 has a home range of approximately 15 to 17 km? Of rhino 5, not enough information is available to even give a rough approximation. From the data we may conclude that home ranges of the Mwabvi rhino overlap considerably and are relatively large compared with 1.0 km? in the Lerai Forest, 6.0 km? in Ngorongoro, 11.7 km? in Olduvai Gorge, Tanzania (Goddard, 1967) and 5.6 to 22.7 km? in Masai Mara (Mukinya, 1973). Home ranges of rhino occupying the short grasslands of the Serengeti plains are obviously larger with 43 to 133 km? (Frame, 1980). As mentioned by Goddard (1967) and Mukinya (1973), in different areas with a similar vegetation structure, but with differences in water availability, home ranges of rhino were significantly larger in areas where water supplies were widely scattered and sparse.
Thangadzi River Reserve was established by the British Protectorate Government in 1928 in order to protect the few black rhino remaining in the country. In 1951, the Mwabvi Game reserve, 131 kmy was proclaimed. In 1975, few people living between the reserve and the Mozambique border were removed and the reserve enlarged to 351 kmy. In 1982, people who before lived in the extension were allowed to return to their villages.
1926 - an Officer of the King's African Rifles estimated 10. ?, students of Aberdeen University estimated 8-30 1975, Ridding said 5 on basis of same Aberdeen expedition 1976 Parker's aerial survey, estimated 4-7.
Although the rhino spent most of the daytime in the thicket and riverine vegetations, it was observed from spoor and middens that during the night they spent significant amount of time browsing in the open mixed woodland.
map of Mwabvi Game Reserve.
Malawi, comparison of footprint and dropping census. Comments in relation to the footprint/droppings method, used during this survey, which can only be applied in areas with low rhino numbers. With higher rhino numbers, an alternative method may be applied. The procedure is as follows: 1. The area is sampled for footprint diameters and boli circumferences, using the transect method described in this paper, whereby the size of the actual grid (width between transacts) and the width of the actual transect determine the accuracy of the result. 2. Only those footprints should be used, where the difference between fore - and hindfeet can be determined and f calculated. 3. The data should be fed into a five-dimensional array of which the parameters are: latitude of datum (I), longitude of datum (II), forefoot diameter (III), f (IV) and bolus circumference (V). 4.The result is a number of five-dimensional clusters, equal to the number of rhino present in the area, where the cluster-size equals the approximate size of the home range. Cluster analysis can be executed with the BIOPAT computer program (Program system for Biological Pattern analysis, developed by P. Hogeweg and B. Hesper: Bioinformatics group, R. U. Utrecht, The Netherlands).
Malawi. During the latter part of the dry season, rhino obtained some of their water ration by eating the tops of young highly poisonous Euphorbia ingens trees. This was frequently observed in the Nyantoko area.
Malawi. During the latter part of the dry season, rhino obtained some of their water ration by eating the tops of young highly poisonous Euphorbia ingens trees. This was frequently observed in the Nyantoko area.
Malawi, census by using footprints. By comparing the means of the different sets of footprint measurements, in combination with differences in f, the minimum number of rhino was estimated to be 5. Rhinos 1 and 2 spent a considerable amount of time in the area around Mwabvi camp, which was sampled at a far higher intensity than the rest of the Reserve. Of rhino 4, several prints of only the fore-feet were found, while it was not certain if the footprints of rhino 5 represent a fore-and hind-foot of one rhino or the hind-foot of rhino 1 (18.20 cm) and a fore- and hind-foot of rhino 5. Because of their weight, footprints of young rhino are not as clear or frequently discovered as those of the older heavier rhino, while in addition areas of the Reserve are not suitable for this exercise because of the structure of the soil or large rock formations. Therefore it is most likely that using this method, a few young rhino were missed. Table 1. Fore-foot and hind-foot diameters and differences between fore- and hind-feet ( f) for five rhino. Standard errors are indicated after mean values. diameter (cm) f Rhino fore-foot hind-foot 1 20.40 ? 0.63 18.52 ? 0.32 1.88 2 22.14 ? 0.61 19.47 ? 0.52 2.67 3 24.06 ? 0.41 21.20 ? 0.38 2.86 4 25.50 ? 0.58 - - 5 18.20? 16.50? 1.70 ? End
The overall distribution of rhino does not seem to change much over the seasons, as old and fresh middens and spoor were evenly distributed over the entire area. The availability of water appears to be the main factor determining minor occupancy differences over the seasons.
