Murchison Falls National Park Research Articles

The effect of long‐term exclusion of large herbivores on soil nutrient status in Murchison Falls National Park, Uganda

SummaryThe effects of long‐term exclusion of large herbivores from a grassland plot on soil nutrient status is described. After 24 years without grazing or browsing pressure an original Sporobolus‐Setaria grassland showed tree regeneration, especially Acacia sieberiana, and resulted in a build‐up of soil organic matter and release of major nutrients into the soil. Chemical analysis shows a dramatic increase in extractable Ca, K and Mg although Mn levels decline, the increase in extractable cations is associated with an increase in pH. Soil organic matter content, organic C and N show an appreciable increase, labile fractions of organic and inorganic P show a marked increase, although a slight decline in total P is detected. The ecological implications of these effects are discussed.RésuméOn décrit les effets de l'exclusion à long terme de grands herbivores dans une zone échantillon de savane sur le contenu en nutriments du sol. Après 24 ans sans effet de pâturage, une savane àSetaria et Sporobolus présentait une régénération d'arbres, en particulier Acacia sieberiana, accompagné d'une reconstitution des matières organiques et d'une libération des principaux nutriments dans le sol. Des analyses chimiques montrent une augmentation drastique en Ca, K et Mg extractibles alors que les niveaux de Mn diminuent, l'augmentation en cations extractibles étant associée avec une augmentation du pH. En ce qui concerne le contenu en matière organique du sol, le C et le N organique accusent une augmentation appréciable, des fractions labiles de P organique et inorganique présentent une augmentation marquée, alors qu'un léger déclin du P total est détecté. Les implications de ces effets sont discutés.

Exploitation of water soluble soil sodium by elephants in Murchison Falls National Park, Uganda

SummaryThe availability of water soluble calcium, sodium and potassium in the Murchison Falls National Park, Uganda was established. In certain local situations elephants have been attracted to particular soils or rocks and have dug them up and ingested them. These sites are characterized by high localized concentrations of water soluble sodium, sometimes associated with calcium. Results are compared with those from other regions of Africa, and it is concluded that under these equatorial climatic conditions elephants are attracted to water soluble sodium. Their requirements may, however, be satisfied to a large extent by sodium in drinking water or in food.

ELEPHANT ECOLOGY IN THE QUEEN ELIZABETH NATIONAL PARK, UGANDA

Summary1. Aerial and ground counts in the Queen Elizabeth National Park from 1963 to 1969 indicate that the number of elephants has more than doubled. The increase appears to be the result of immigration rather than reproduction.2. Elephant food habits were studied for 10 months in two areas of the Park. In the short‐grass/thicket area, browse intake rose markedly whenever the rainfall fell below 50 mm/month. In the tall‐grass area without thicket, herbs were eaten frequently during the rains and Cymbopogon grass bases in the dry season.3. Food availability had an important influence on the diet of elephants. Sometimes, however, elephant were very selective, e.g. for Panicum maximum, Azima tetracantha, Securinega virosa, and Tribulus terrestris. Certain grass inflorescences were selected during the rains, and bases in the dry season.4. Most browse was consumed in the thicket area during the dry season and most grass was eaten in the tall‐grass area of the Park.5. Stomach and faecal samples gave a similar result and indicated that the diet in the tall‐grass area was comparable to that of elephant in Murchison Falls National Park.6. Analyses of important plant species showed that, in general, tall‐grass had a lower crude protein content than short‐grass, herbs and browse. Browse leaves had a relatively high crude‐protein content in the dry season. Differences were less marked in the rains.7. Ether extract, or fat content, was high in browse leaves and in Cymbopogon, in particular its bases. These may have been selected in the dry season for this reason.8. Grass and browse stems were very fibrous and this may have contributed to their being avoided.9. High carbohydrate levels probably enhanced the palatability of grass bases and browse leaves.10. Grasses were very siliceous, in particular their bases when contaminated with soil. Elephant took considerable trouble to remove soil. Browse leaves had little silica but were rich in other minerals, and this may have contributed to their greater palatability.11. Studies of woodland dynamics show a decline in large trees which corresponds to the increase in elephants. In some cases trees have been almost eliminated. Damage to trees indicates that a most important factor in their decline is the elephant. There is some evidence that the trees are eliminated selectively.12. In the tall‐grass area there has been an increase of 46.3% in elephant numbers, but a decline of 80.3 % in buffalo, over the past 15 years. An overall decline in combined biomass of 36.9 % is calculated. Estimates of energy utilization of the annual vegetation production by elephant and buffalo indicates a decline from 6.1 % to 3.9% over this period.

Iron Age Archaeological sites in the Chobi Sector of Murchison Falls National Park, Uganda

Summary The Chobi sector of Murchison Falls National Park, Uganda, is rich in archaeological material, particularly pottery, which litters the banks of the Victoria Nile. Three major pottery types are represented: Urewe ware belonging to the Early Iron Age and dated to the third century A.D.; a hitherto undescribed type designated Chobi ware, which is probably partly contemporary with and partly later than Urewe ware; and roulette decorated pottery of recent type. Late Stone Age lithic material is also common in the area but is not described in detail.

CROCODILE DISTRIBUTION AND STATUS IN THE MAJOR WATERS OF WESTERN AND CENTRAL UGANDA IN 1969

Summary This report presents the results of a survey into the current status of the Nile crocodile in the major waters of central and western Uganda, made on behalf of the Uganda Fisheries Department and the Trustees of the Uganda National Parks. The waters covered by the survey are described briefy Crocodile numbers and distribution were assessed by diurnal aerial counting and nocturnal ground counts as described by Graham (1968). The major sources of error inherent in these techniques are recognised and discussed. Efforts to reduce bias in results included the use of a light helicopter to obtain data for comparison with those obtained from a conventional aircraft. Comparative costs are also presented. Inaccessible areas of dense papyrus were searched at night from a helicopter equipped with a spotlight. Information was obtained from fishermen in Lake Albert on the status of crocodile to corroborate other results. The analysed results of aerial and ground counts give estimates of less than 100 crocodile outside the Murchison Falls National Park, indicating the species' reduction to the status of an ‘occasional’ or ‘rare’ animal. Within the National Park crocodile occur in two populations separated by the Murchison Falls. Below the Falls it is estimated that there are 1064 crocodile, and above 433. By use of aerial photography 369 crocodile from the larger of the National Park's populations were measured for length. From Graham's (1968) age/length data, age classes are ascribed to those measured. This, together with data from the counts, permitted the computation of a survivorship curve for the population. This is presented with two possible alternatives. From these curves it does not appear that the population is declining through lack of recruitment. From the aerial photographs river banks are classified into four crude categories. By relating crocodile in the photographs to the nearest bank category, it is shown that they have a marked preference for sandy banks over swampy shores, hard flat earth or cliffs. It is also shown that smaller crocodile make more use of swampy areas than larger specimens. Biomass densities for both crocodile populations in the National Park are computed. The larger shows a biomass of 347 kg/km of shoreline which compares with 350.2 kg/km for Lake Rudolf (Graham's (1968) data modified), the smaller 75.3 kg/km. The decline of crocodile in Uganda is attributed to expanding human populations and over‐exploitation for skins. Recommendations for the future conservation and management of crocodile are presented. These are based on reducing immature mortality rates by hatching eggs and artificially rearing small crocodiles for a period of 6 months after hatching. Some of these should be used to augment recruitment in the National Park populations, and the surplus placed in other waters until of an exploitable size.

THE GROWTH AND NUTRITION OF THE AFRICAN ELEPHANT

SUMMARYIn order to gain information on the growth and nutrition of two populations of elephants in Murchison Falls National Park, Uganda, their urinary excretions of hydroxyproline peptides (HP) were compared.Animals from the “south bank” population had a consistently higher level of excretion than corresponding animals from the “north bank” population. This indicated a faster rate of growth and a superior nutritional status in “south bank” animals at the time of sampling.The HP output from both populations was found to run parallel to the seasonal variation in rainfall and vegetation growth. Sampling from each population was carried out at a different time of the year and evidence is presented to show that the differences in the rate of growth are a direct result of this. It is concluded that any primary differences between the populations are small enough to be obliterated by seasonal changes.The effect of the seasons on the growth of the elephant is therefore examined in more detail, and a direct influence on collagen metabolism is discussed.

Nile Crocodile Faces Extinction in Uganda

Dr Cott's report on the status of the Nile crocodile in Murchison Falls National Park, in Uganda, shows a most alarming situation, with poachers gaining the upper hand. At one place where crocodiles were once so numerous that at times it looked as if the whole beach were moving into the river there are now none at all. In the battle against the poachers it is urgent to equip the park rangers with two-way radio sets to replace the present system of signalling by fire (which also warns the poachers), and the FPS has agreed to provide these sets out of the FPS/WWF Revolving Fund (see page 319). Dr Cott's other recommendations include putting a stop to disturbance by tourist and other launches and the reduction of some predators.

Land use Proposals for Murchison Falls National Park and Surrounding Area

(1968). Land use Proposals for Murchison Falls National Park and Surrounding Area. East African Agricultural and Forestry Journal: Vol. 33, Proceedings of the Symposium on Wildlife Management and Land Use, Nairobi, 5–8 July 1967, pp. 19-22.

Change in Population Number and Reproductive Rate of Elephants in Uganda

Four aerial counts of elephants (Loxodonta africana) on a 1,500-square-mile area, including the southern two-thirds of Murchison Falls National Park and vicinity, Uganda, were made from July, 1963, to May, 1964. The average number of 6,750 elephants was about 1,000 below the average counted in the same area in 1958-59. An unusually long dry season between mid-June and early November, 1963, caused an early movement of elephants from the grasslands of the study area to the woodlands outside. With the onset of rains in late November, elephants began moving back to the study area. They continued this movement into the December-March Dry Season, concentrating near streams and in unburned woodlands of green vegetation. During the March-May Rainy Season major migrations occurred. The highest count was enumerated at this time and elephants were widely distributed. On two adjacent areas to the north (Tangi-Karuma area and the Elephant Sanctuary) three aerial counts indicated similar distributions and seasonal movements. However, data from four aerial counts in 767square-mile Queen Elizabeth National Park in southwestern Uganda showed different seasonal distributions and movements: 1,758 elephants in the June-August Dry Season, 1,329 in the August-November Rainy Season, a further decline to 1,295 in the December-March Dry Season, and an increase to 2,222 in the March-May Rainy Season. Annual increment varied inversely with population density. The highest increment (8-9 percent) was in Q. E. Park where the average density was 2.2 elephants/square mile and restrictions on migrations are minor. The next highest annual increment (7-7.5 percent) was on the combined Tangi-Karuma area and the Elephant Sanctuary, north of the 1,500-square-mile study area. Here the average density was 2.8 elephants/square mile and migrations have not been appreciably restricted. The lowest annual increment (6-6.5 percent) was obtained on the 1,500-mile study area where density averaged 4.5 elephants/square mile. It is here that drastic changes have occurred to distribution of elephants, and serious restrictions have been imposed on their migratory behavior. Results of 12 aerial counts of elephants, conducted between January, 1957, and August, 1959, on a study area which included the southern two-thirds of Murchison Falls National Park, Uganda, were reported by Buechner et al. (1963). In the present report, results of four aerial counts on the same area, conducted between July, 1963, and May, 1964, are presented primarily to show the changes that have occurred in number and annual increment of elephants during the past 5 years. We also conducted aerial counts north of this study area and in Queen Elizabeth National Park, Uganda, for comparative information on numbers, annual increment, seasonal distribution, and migratory behavior of elephants. We hope that this information, by emphasizing the deleterious effects of an excessively dense population, will provide a basis for better management of elephants in these and similar areas of East Africa. Definitions of the terms family unit and herd follow those given by Buss and Smith (1966:376). The term group refers to any coordinated assemblage of elephants not identified as belonging to a more specific category. A concentration is defined here as a loose and uncoordinated assemblage of elephants occurring as singles or any combination of categories. We are grateful to the New York Zoological Society for providing funds to conduct most of the aerial counts. The Uganda National Parks and the Uganda Game Department contributed supplementary funds that allowed us to include the northern areas (Tangi-Karuma and the Elephant Sanctu-

AGE CRITERIA FOR THE AFRICAN ELEPHANT

Summary1. The paper is based on a collection of 385 lower jaws of the African elephant (Loxodonta a. africana Blumenbach) from western Uganda.2. Thirty age groups are described and illustrated, which are related to the progress of eruption and wear of the six teeth in each side of the lower jaw.3. Correct identification of individual teeth in the series is essential and several checks are described. Thus, when length is plotted against width for the six teeth the points fall into six well ‐ defined groups. Frequency distributions of laminary indices and lamella numbers support the belief that teeth have been correctly identified, but overlapping, distributions preclude identification on these characters alone.4. The presence of abnormal seventh molars in four jaws is described.5. Chronological ages have been assigned to the relative age groups. Information on age and growth of captive animals has been considered and the general form of the growth curve established. Arbitrary estimates of the intervals between successive age groups were made and subsequently checked against growth and seasonal ridges on the roots. These indicate an upper age limit of about 60 years, which is compatible with fuller information on Indian elephants.6. Growth curves support the validity of the ages assigned. Asymptotic heights at shoulder (∞) are respectively 317 cm and 298 cm for males from Murchison Falls and Queen Elizabeth National Parks. For females no distinction is made (because the sample from the latter area is small) and ∞ is 272 cm.7. Growth in weight has also been established but shows no significant differences between the two populations. The mean maximum weight of females is 2766 kg (6100 lb), and of males 5450 kg (12000 lb). Growth apparently continues throughout life.8. Tusk growth is analysed. There is a linear increase in weight of female tusks from eruption at 1–3 years up to the oldest group, with an indicated mean combined weight of 17.7 kg (39 lb) at 60 years. Male tusks show an increasing rate of growth throughout life to a mean combined weight of about 109 kg (240 lb) at 60 years.Big tusks are generally the result of prolonged growth; extremely big tusks probably result from prolonged and above average rate of growth.9. Seasonal and annual incremental layers on the root 3 of the teeth are briefly described; these give an objective estimate of the chronological intervals between the relative age groups.10. Field age criteria are presented which are derived from these growth curves.11. The age at puberty in the female elephant is discussed and compared with earlier conclusions. There is evidence of a retardation in recent years in the Murchison Falls National Park (South bank) population and of a lengthening of the mean calving interval. This considerable depression of the reproductive rate, which is almost certainly density dependent, agrees with the observed lower recruitment in this population.12. Survivorship curves constructed from material representing 325 natural deaths are presented for the two populations. If estimates of the age at puberty and the reproductive rate are taken into account, the expected differences in recruitment are found.13. The calculated mean expectation of life is less than 15 years.14. Mean individual weight is estimated at about 3800 lb.

Observations on Reproduction and Breeding Behavior of the African Elephant

Observations on the breeding behavior of the African elephant (Loxodonta africana) in Uganda show that some wild females begin to breed at approximately 7 years and all females breed by approximately 11 years of age. A declining population and lower annual increment of elephants south of the Victoria Nile River in Murchison Falls National Park are associated with an average postpartum preconception interval more than three times longer than the 24.1-month (sic) period reported in 1953 by Perry. The change in length of this interval is possibly a function of self-regulation in population numbers. At least in some parts of its range, the wild African elephant breeds throughout the year with no distinct seasonal acceleration. Corpora lutea present during early pregnancy are not replaced during a subsequent stage of pregnancy but are maintained throughout gestation and for about 2 months after parturition. Old or degenerate corpora lutea persist for at least 4.5 years postpartum. Apparently in some animals corpora lutea develop before conception, whereas in others, conception apparently occurs when corpora are established. At least two graafian follicles may ovulate and develop into corpora lutea within a short time. Cows have multiple mates, there is no prolonged male-female relationship, and frequently there is no fighting by bulls over females. Information concerning breeding and reproduction of the African elephant is limited. One of the most extensive reports directed entirely to various aspects of reproduction of the African elephant is that of Perry (1953). His study is devoted largely to describing the female reproductive tract, and emphasizes ovarian characteristics. Recently, Johnson (1963) reported extensively on histological and quantitative characteristics of the testes of the African elephant. He includes observations on the teeth and pituitary gland, and presents evidence that suggests the possibility of individual cyclicity in reproductive activity of adult males. Short and Buss (1965) detected no progesterone in 11 corpora lutea from six African elephants in various stages of the estrous cycle and pregnancy, postulated a relatively short functional and long structural life of the elephant's corpus luteum, and suggested that some corpora lutea developed prior to conception. The first three chapters of a monograph by Hill et al. (1953:11-67) on the elephant in East-Central Africa include general information on reproduction. The anatomy of the male reproductive system has been reported on by Mojsiscovics (1879), Oudemans (1892), and Schulte (1937). Data on age at sexual maturity and duration of gestation are provided by Seth-Smith (1932), Hundley (1934), Burne (1943), and Flower (1943). The African elephant breeds throughout the year, at least in those areas for which data are available. Krumbiegel (1943) and Ansell (1960) observed calves throughout the year. Perry (1953) noted fetuses of variable age in cows collected throughout the year in Uganda. Buss and Brooks (1961) and Buechner et al. (1963) found no evidence of seasonal peaks in parturition and concluded that breeding occurs throughout the year in Uganda. Considering that environmental conditions within the African elephant's extensive range are highly variable, and that information has been secured from a limited part of this range, the possibility of seasonal breeding in some areas cannot be ruled out. The purpose of this study was (1) to study structures of 120 pair of ovaries from

Behaviour and ecology of the wild Patas monkey, Erythrocebus patas, in Uganda

Prior to the present study, no systematic field data were available on the behaviour and ecology of Erythrocebus patas. This monkey, widely distributed over the grass and woodland savannah regions of West and East Africa, appears to be unique in some of its physical and social adaptations to a terrestrial mode of life. In three main study periods, 640 hours of observation were carried out on groups in the Murchison Falls National Park. Small samples of data on baboon and vervet groups in the same area were obtained. Numerical sizes of patas groups ranged from 9 to 31, mean 15. In no group was there more than one full‐grown male. Groups were followed for many successive day‐ranges, distances travelled varying from group to group, season to season, with a maximum of about 12,000 m and a minimum of 500 m. Home range size of one group was 5200 hectares. Groups tended to use a different area of the home range each night, and individuals dispersed far apart in taking up night resting positions in trees. The day activity pattern comprised two main feeding periods, with a rest period of one to three hours in the hottest time. Drinking at water holes or other sources was infrequent.Infants less than three months old occurred only up to June, and were commonly seen in March and April. Infants aged 3 to 12 months, and juveniles, engage frequently in long, active bouts of play‐chasing, wrestling, and bush‐bouncing–almost all play is on the ground. Grooming amongst them is common, its social pattern being similar to baboons. Submissive gestures are very rarely seen, baboon‐like presenting and being mounted not occurring. Threat‐attack is mainly by adult females, very rarely by the adult male. Vocalizations audible at about 100 m occur very infrequently (about two to four a day, compared with 25 to 50 for baboon groups).The adult male patas plays the part, for the group, of watchdog. Whenever the group is disturbed, or approaches new areas, he may reconnoitre from a high point several hundred metres away from the group. When disturbed by the observer, he has a noisy, bouncing display on bushes and trees, and probably a form of diversionary display by running away from his group and from the observer. In the group, he is spatially peripheral, except when day resting, mating and grooming, and the adult females habitually initiate directions and times of group movement. Their function is essentially that of looking after themselves, their infants, and the juveniles, while that of the adult male is very strikingly that of watching for predators or other patas groups or baboons, etc. Isolated adult males and one all‐male party of four have been observed. Spacing between groups is such that inter‐group encounters are exceedingly rare (two occurrences only). Reaction consisted of chasing by the larger group, rapid avoidance by the smaller. A contralto bark is uttered repeatedly, in short series, by the adult male of a group only, it seems, on encounters with extra‐group patas.The patas adaptations of swift locomotion, silence, concealment, and dispersal, contrast very clearly with those of the much noisier, larger, more aggressive baboons in whose groups there are usually several adult males.Further research on the species is required from West Africa, and captivity studies must be used to determine the precise nature of the social organization amongst the adults and the processes of socialization.

Catching and Carting White Rhino in Uganda

In 1961 the Uganda National Parks captured ten white (squarelipped) rhinoceros in West Madi district, west of the Albert Nile, where (hey were being poached out of existence, and transferred them to the Murchison Falls National Park. The operation was financed partly by Anglia Television and described by John Savidge in ORYX, September 1961, vol. VI, 5. Unfortunately the six animals released in the park included only two cows and no mature bull, and the chances of their reproducing were small. So in 1964 a second operation was mounted, financed by the World Wildlife Fund. In this article the author, then Scientific Warden of the Murchison Falls Park, describes this operation which captured and released another five rhino, four of them cows. This greatly improves the chances of breeding, and with freedom from poaching in the park, the rhino now have a reasonable chance of building up the herd.

Numbers and Migration of Elephants in Murchison Falls National Park, Uganda

Numbers and Migration of Elephants in Murchison Falls National Park, Uganda

Vegetation Change Induced by Elephants and Fire in Murchison Falls National Park, Uganda

Vegetation Change Induced by Elephants and Fire in Murchison Falls National Park, Uganda

The Introduction of White Rhinoceros into the Murchison Falls National Park, Uganda

The Northern race of the Square-lipped (White) Rhinoceros (Ceratotherium simum cottoni) occurs in small numbers west of the Albert Nile in Uganda (in the West Nile and West Madi districts); in the N.E. Congo (where, at least until June, 1960, it was most numerous in the Garamba National Park); in the S.W. Sudan (in the Nimule National Park and elsewhere), and in Ubangi Shani.