Elephant Ecology in the Queen Elizabeth National Park, Uganda

Abstract

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.

A cost-benefit analysis of protecting Lake George wetland resources in Queen Elizabeth National Park, South Western Uganda

“…In each village the dominant ethnic group is drawn from the surrounding communities. As reported by Infield (1989), an ethnic group represented in most villages is Abanyanja -"the people who stay near water" with tribe divided into three clans as shown in Table 1. Government in 1952 gazetted QENP at a time when several fishing villages existed in the area were gazette.…”

“…A decision was made to allow these existing enclave villages to remain. Lake George supported a significant artisanal Fishing industry and indeed, these Lake was reported as one of the most productive inland waters for fisheries in Africa which could not be left unexploited (Infield, 1989).…”

“…During the early years, attempts were made by QENP to retain control of the village populations and the activities that were carried out in them. The park authorities viewed the fishing villages as work camps for fishing industry rather than real communities (Infield, 1989). Fishermen and their helpers were expected to leave their families behind when entering the fishing villages to work.…”

Changes in the woody component of an East African savanna during 25 years

“…in the deciduous savanna (Table 4). This indicates that a change in species abundance due to elephant browsing may not only be the result of preferential selection by elephants (Field 1971, Guy 1981, Jachmann & Croes 1991, Lewis 1991, Vesey-FitzGerald 1973a, but also the result of the differing ability of tree species to respond to damage by coppicing (see also Barnes 1983a).…”

Woodland Conversion by Elephants in Africa: The Search for Causal Factors, Processes, Mechanisms and Management Strategies

“…In wet season, grasses constitute 70% of elephant diet, but progressively shift to more browse proportion in dry season [25]. This is probably because grasses tend to rapidly become fibrous as dry season progresses, thereby diluting the nutrient content and therefore elephants turn to browse which is a critical dry season food reserve as its crude content is then higher than that of grasses [14] [26] [27]. Furthermore, Guy [21] [22] and Barnes [23] indicated that debarking of trees by elephants frequently occurs during late dry season when there is increased nutrient translocation from roots to new foliage and flowering parts.…”