CONSERVATION ISSUES IN UGANDA
LAND CLEARING
The history of land use outside Kibale suggest that forest clearing began in Uganda approximately 1000 BP. While some is due to illegal encroachment into protected areas, most clearing has taken place on public lands. Forest clearing throughout the country has been extensive in the last 200 years, particularly in the last 50 years. Estimates of Tropical High Forest cover in Uganda have decreased from 12.7% in 1900 to 10.8 % 1926, to 4.6% in 1958 to < 3% in 1987. Of the remaining forest, an estimated 2% is lost each year.
Arable land in Uganda takes up 49% of the country, of which 35% is under cultivation. The areas most affected by degradation are the ungazetted tropical high forests, woodland and bushlands. These are major sources of timber, charcoal and firewood, and are also used as grazing and subsistence agriculture. The average population growth rate in Uganda is currently estimated at 2.5% per year. This increase in population has led to growth in demand for food, energy and other forest products. Expansion of agriculture onto previously forested steep terrains has lead to soil erosion, which has lead to siltation of rivers and lakes and loss of water catchment basins.
HABITAT CHANGE AND FRAGMENTATION
The distance the fragments or patches are from the main forest block may determine whether or not chimpanzees are able to use the fragments and maintain viable populations. Chimpanzees are able to move through various habitats and have been known to cover several kilometres through savannah grassland to reach distant forests patches or isolated fig trees. Whether these patches are used permanently or temporarily is yet to be determined.
In the past five years the Masindi district has seen the expansion of sugar cane fields and the erection of a factory for processing the sugar cane. This has lead to the conversion of riparian forests to cropland. Small chimpanzee populations are now cut off from the main forest blocks such as Budongo. These small populations face local extinction if females are not able to disperse to other communities.
It is noted that in Kagombe Forest Reserve there are only about 80 chimpanzees left instead of the expected 300-500 based on the size of the forest block. The cause of the severe reduction in chimpanzee numbers has been the heavy encroachment and conversion of closed canopy forest into agricultural land or the cutting down of trees for firewood, which has altered the structure of the forest. This habitat change and fragmentation is a direct result of high human population growth, the increased demand for arable land, and the expansion of urban areas.
Researchers also found that during the years of political and economic instability, farmers had encroached into the area that is now Kibale National Park and degraded approximately 79kmsq of forested land. This has lead to the loss of 200 chimpanzees and 52,612 monkeys, based on the estimated animal biomass of Kibale Forest.
In Budongo forest the practice of weeding out the ficus species in order to encourage Ironwood trees (Cynometra) to regenerate at a faster rate for the timber industry, has affected chimpanzees because it reduced one of their main food sources. This alteration of the forest structure may be the reason for the variation in density levels between Kibale and Budongo forests.
Wildlife Conservation Society reports indicate a loss of 435kmsq of forests outside the protected areas was recorded by Landsat images. In addition, the size of Ugandan forests rarely exceeds 400 kmsq of tropical-high forest (additional land consisting of savannah or montane grassland occurs in most of the gazetted forest reserves, boosting their size). This surface area may be insufficient to sustain some of the larger-bodied mammals in the long term because their population sizes will be too small to be viable, and factors such as disease and genetic inbreeding may lead to their long-term decline and eventual extinction.
POACHING AND HUNTING
The impact of commercial hunting on forest mammals is yet to be fully determined, but current information indicates that most hunting of primates is unsustainable. While hunting of primates, particularly chimpanzees, is not considered common in Uganda, the survey work carried out between 1999 and 2003 found that chimpanzees were targeted in six of the eleven major forest blocks. The reason was not consumption for humans, but rather predation for either meat for hunting dogs, crop raiding or witchcraft. Consumption of other species, such as duikers and bush pigs is common.
SNARE INJURIES
Hunting has an indirect impact on chimpanzees and other primates through the use of snares or jaw traps by hunters. Most of these snares are made from wire. As chimpanzees walk through the forest, their hands or feet may become trapped in the snare. In two of the forests where chimpanzees are studied (Kibale and Budongo), researchers have observed up to 25% of chimpanzees with snare-related injuries. Researchers found that chimpanzees with injuries to the upper limbs experienced severe limitation in both dexterity and control while processing foods such as figs, the major food source of their diet. Chimpanzees with injuries appeared to show remarkable compensation in feeding abilities, but there is concern for the ability of individuals to survive under extreme competition. Researchers found that adult females behaved differently when injured: they were more likely not to socialise in larger mixed-sex groups; they often only associated with related offspring; they exhibited a reduction in maternal behaviour; they groomed others much less; and finally, they travelled less and were more cumbersome in the trees than non-injured females.
The death of individual chimpanzees has been attributed to either wire snares, or mantraps on several occasions. The death of an adult male chimpanzee in the Kasokwa Forest Reserve near Budongo in July of 2000 occurred from such a trap. In Kibale Forest, researchers recorded the death of a young adult female and her orphaned brother due to snare injuries. She was unable to climb or gather food.
GENETICALLY VIABLE POPULATIONS
Although, work has been done on genotyping chimpanzees in the wild, little work has been done in Uganda on genetic variability in isolated populations. There are studies from other sites that indicate dispersal by females can reach long distances. At Gombe Stream National Park i Tanzania, evidence of gene flow through female dispersal has occurred through maternally transmitted genotypes. Detection over distances of 600-900 km within each subspecies supports the hypothesis that high amounts of gene flow may account for low amounts of morphological differentiation in chimpanzees.
There is increasing concern for the future of small isolated populations of chimpanzees. In Gombe Stream National Park, one community has had over 50% of the adolescent female chimpanzees remain in their natal community. These females face the risk of breeding with related males. A number of authors state that females appear to avoid mating with related males within the community but this avoidance is not absolute. There is a known conception from a mother/son mating in this community. The infant male died during an epidemic of sarcoptic mange. This is the only infant out of seven from this female who has died. Whether the cause of death is related to poor genetic fitness is uncertain. But such incidences raise concern for chimpanzee populations that are becoming increasingly isolated from other communities.
CONSERVATION STRATEGIES DEVELOPED IN UGANDA
The first concerted effort to develop a conservation strategy for chimpanzees in Uganda evolved in 1997. At the invitation of the Director of the Uganda Wildlife Authority (UWA), Dr. Eric Edroma, the Conservation Breeding Specialist Group (CBSG) conducted a Population Habitat Viability Assessment (PHVA) workshop to determine the threats to the survival of the chimpanzees in Uganda. Experts from within Uganda and elsewhere in Africa came together for the five-day workshop. Five areas of concern were identified by the workshop participants:
(1) distribution and habitat;
(2) threats;
(3) population biology and modeling;
(4) ecotourism and education; and
(5) captive management
POPULATION VIABILITY ANALYSIS
One of the important tools that were used in the workshop was a population viability analysis (PVA) modelling programme called VORTEX. Vortex is an individual-based, age structured population simulation model. Carrying capacity, demographic stochasticity, environmental stochasticity, inbreeding depression and catastrophes are generally included in the model.
In the VORTEX model, the degree of heterozygosity retained in most populations after 100 years is a function of their size. The largest populations (N=600) retain 99.3% of its original heterozygosity, while the smaller populations (N=25) retain just 81.5%. This increased loss of genetic variation in very small populations may lead to a reduced capacity to respond to long-term environmental changes.
Added catastrophes such as mortality from hunting or poaching increased the risk of extinction from a baseline level of 61% to 77% in smaller populations over 100 years. This was modelled on a population of 100 individual each year, with the pretence of only losing one additional female from the population each year.
Currently, the majority of the larger and smaller populations of chimpanzees in Uganda are isolated from one another. Populations that are linked by corridors allow periodic migration of adult females, which reduces the risk of extinction in nearly all cases compared with populations isolated from its nearest neighbours. The VORTEX model showed a 55% increase in survival for a population of 100 individuals connected to another population over an isolated population.
As well as a reduction in the risk of extinction, the influx of new individuals into sub-populations by migration lead to an increase in the level of heterozygosity that is retained within that subpopulation. The increase was most notable in the smaller populations.
CONSERVATION ACTIONS TAKEN FROM THE PHVA WORKSHOP
At the completion of the 5-day workshop a series of recommendations were made by the participants. One of the main recommendations was the surveying of major forest blocks to establish the number of chimpanzees in each of the forests. Conservationists, the UWA, and the Uganda Forest Department (now known as National Forest Authority [NFA]) could then develop a long-term strategy from the Vortex analysis to ensure viable populations of chimpanzees are maintained. The Wildlife Conservation Society and the Jane Goodall Institute, collaborated along with UWA and NFA to carry out the survey work between 1999 and 2002. Apart from establishing the populations of chimpanzees in each forest block, other mammals and human activities were recorded.
Recommendations were made to carry out research on the snaring practices by hunters in relation to the impact on chimpanzee survival, while also establishing programmes to increase patrols to deter illegal activities in the protected areas. The Jane Goodall Institute, along with long-term research projects such as the Kibale Chimpanzee Project, under the Direction of Dr. Richard Wrangham and the Budongo Forest Project, established these programmes which are ongoing. Research on the impacts of snare injuries to chimpanzee survival has been carried out by various researchers. In addition to the above recommendations, others were indicated along with action points and who should be responsible to carrying out those actions.
Download Population and Habitat Viability Assessment 1997 (Adobe PDF 4.32MB)
REVISED ACTION PLAN 2003
At the completion of the survey work carried out by the Wildlife Conservation Society and the Jane Goodall Institute, a second workshop was held to review the information gathered from five years of research and to develop a revised strategy for the conservation plan for chimpanzees in Uganda.
This workshop differed from the PHVA in that participants had more information to utilise in developing a strategic plan. This was in part due to the work carried out on the recommendations of the PHVA. The objectives of the workshop were to;
(1) review activities undertaken since the 1997 PHVA;
(2) disseminate the results of the chimpanzee census;
(3) identify the current threats to chimpanzees in Uganda and
(4) develop a five-year action plan.
The format used to develop the action plan was based on a participative process which involved analysing;
(1) the laws and policies affecting chimpanzees;
(2) the main stakeholders that affect chimpanzees;
(3) the creation of a problem tree that develops a cause-effect model to explain why chimpanzees are endangered. From this problem tree a long-term vision and a five-year goal for the action plan, including objectives and development of projects that together will meet the objectives.
The problem tree broke down the threats to chimpanzees in Uganda using a logical sequence of cause and effects. The premise was that chimpanzees are endangered in Uganda because their population is low. This is either a result of the fact that they are normally low or because the population is declining. The densities of chimpanzees are some of the highest in Africa so that the 'naturally low' reason was not likely. The tree therefore worked on the premise that the population is declining either due to low birth rates, high offspring mortality or loss to the pet trade, or high adult and juvenile mortality.
Download Revised Conservation Action Plan 2003 (Adobe PDF 0.95MB).
GREAT APE SURVIVAL PROGRAMME
The Great Ape Survival Programme (GrASP) was established in 2000 during the CITES, Conference of Parties meeting held in Nairobi. The initiative was jointly undertaken by the United Nations Environmental Programme (UNEP) and the United Nations Education, Scientific and Cultural Organisation (UNESCO). As part of the programme, the GrASP executive committee asked each of the 23 national governments where great apes occur to become a partner in the programme. One of the first steps was to develop a national action plan for each of the great ape populations existing in all 23 countries.
Uganda was one of the first countries to sign the agreement. Over a period of two years, a committee formed by the Ministry of Trade, Tourism and Industry (MTTI) compiled information based on past research into the conservation actions required to conserve the two great apes that exist in Uganda (Pan troglodytes schweinfurthii and Gorilla beringei beringei). Committee members include Conservation NGO's; Government Agencies; University Departments and Ministry Representatives. To date, the action plans and project activities have been developed for both species and ratified by the Minister of MTTI thus these action plans are government documents.
