OVERVIEW OF CONSERVATION STRATEGIES FOR PRIMATES IN AFRICA.
IUCN (The world conservation Union) has been one of the main forces behind most conservation strategies for threatened species. IUCN was founded in 1948 and several years later setup the species survival commission (originally called the Survival Service Commission and was renamed in 1981). The commission has participants from governments, government agencies, NGO’s, scientists and other interest groups from around the world. The commission has created specialist groups for each of the plant and animal taxon. The primate specialist group compiled a strategy action plan for primates in Africa in 1986 and a revised edition in 1996. These action plans set priorities among primate taxa for conservation action, identifying the regional primate communities and making recommendations for conservation actions.
CONSERVATION ISSUES IN UGANDA.
Forest clearing in Uganda has been occurring for centuries. While some clearing is illegal encroachment of protected areas, most has taken place on public land. Forest clearing throughout the country is extensive, greatly escalating in the last fifty years. Estimated tropical high forest cover in Uganda has gone from 12% in 1900 to less than 3% in 1987, with an estimated additional 2% loss every year.
Areas most affected by degradation are unprotected tropical high forests, woodland and bush serving as major sources of timber, charcoal, firewood, grazing, and subsistence farming. Uganda’s population is growing a rate of 2.5% per year, leading to a growth in demand for food, energy and other forest products. Expansion of agriculture onto previously forested steep terrains has also led to soil erosion, siltation of rivers and lakes, and loss of water catchment basins.
HABITAT CHANGE AND FRAGMENTATION.
Chimpanzees are able to move through multiple habitats and have been known to cover several kilometers to reach distant forest patches or isolated fig trees. Fragmented land areas can make this difficult or impossible and often leads to human-chimpanzee conflict and death of chimpanzees.
In the past five years, the expansion of sugar cane fields and the construction of new factories for processing in Uganda’s Masindi district has led to the conversion of riparian forests to cropland and business development. Small chimpanzee populations are now cut off from major forest blocks and face extinction if the population’s females are unable to move to new communities.
In Kagombe Forest Reserve only an approximate eighty chimpanzees exist in a forest block that should have at least 3-500 based on its size. The cause of this dramatic reduction in numbers is the extensive and rapid encroachment and conversion of the area’s canopy forest into agricultural land and firewood, altering the entire structure of the forest. This fragmentation is a direct result of human population growth, increased demand for arable land, and expansion of urban areas.
Researchers also found that during political and economic instability, farmers near Kibale National Park encroached into wild habitat and degraded approximately 79 square kilometers of forested land, leading to the loss of over 200 chimpanzees and 50,000 monkeys. In Uganda’s Budongo Forest, the practice of weeding out Ficus plants to encourage the growth of Ironwood trees for the timber industry has greatly impacted major food sources of local chimpanzee populations.
Wildlife Conservation Society reports indicate a loss of over 400 square kilometers of forest outside Uganda’s protected areas. In addition, the size of Ugandan forests rarely exceed 400 square kilometers, making them often insufficient to sustain large mammals long term. Small population size combined with disease and genetic inbreeding may lead to ongoing decline and the eventual extinction of more vulnerable forest species.
POACHING AND HUNTING.
The full impact of commercial hunting on forest mammals is yet to be fully determined, but current studies indicate that most hunting of primates is unsustainable. While hunting of primates, particularly chimpanzees, is not common in Uganda, surveys conducted between 1999 and 2003 found that chimpanzees were targeted in six of the country’s eleven major forest blocks. In many countries, poaching of primates is for human consumption. However in Uganda, major reasons given included provision of meat for hunting dogs, deterring supposed crop raiding and witchcraft.
Even hunting for species other than primates has an negative impact on chimpanzees due to the use of snares and jaw traps. Most snares are made from strong wire and as chimpanzees walk on the forest floor, hands and feet become trapped. In two of Uganda’s forests where chimpanzees are studied (Kibale and Budongo), researchers have observed up to 25% of chimpanzees as having snare-related injuries. Researchers found that chimpanzees with injuries to their upper limbs experienced severe limitation in both dexterity and control while processing foods such as figs, a major food source. While chimpanzees with injuries do show remarkable adaptation, the inability to fully compete for food often makes them unlikely to survive long term. In addition, adult females behave differently when injured and are more likely not to socialize in larger mixed gender groups, often only associating with related offspring. These chimpanzees exhibited a reduction in maternal behaviors, groomed others much less frequently and traveled less due to cumbersome injuries when moving about through the forest.
The death of individual chimpanzees due to snare and trap injuries has been recorded on several occasions in Uganda.
GENETICALLY VIABLE POPULATIONS.
Although some work is being been done on genotyping wild chimpanzees, little has been conducted related to genetic variability in Uganda’s isolated populations. Studies show that females may move to new communities long distances from home territories. At Gombe Stream National Park in Tanzania, evidence of gene flow through female dispersal has occurred through maternally transmitted genotypes. Easch of the four chimpanzee subspecies exist over distances of 6-900 kilometers, supporting the theory that significant levels of gene flow may account for their lack of great morphological differences.
Isolation of chimpanzee communities may lead to genetic instability leading to the spread of disease and even death. In Gombe, one community over 50% of adolescent females have remained in their natal community, creating a risk of inbreeding. Researchers at Gombe have found these females generally avoid mating with males related to them but this is not absolute. In one known conception resulting from a mother/son mating, in this community, the infant eventually died from a non life threatening illness. The only infant of seven babies born to this mother, cause of death may have been related to poor genetic fitness, making the issue of population isolation of great concern.