Dance My Ph.D - Ecological and Evolutionary Perspectives on Elephant - Woody Plant Interactions in African Landscapes
This dance is a celebration of the intimate co-evolutionary and symbiotic relationships between two of Africa’s most iconic animals and plants: African elephants and acacia trees.Prior to the rise of human civilization, African elephants had ranged throughout nearly all areas of the African continent for more than 2 million years. Elephants inhabited virtually any area where they could find sufficient resources of food and drinking water to sustain their lives, ranging into hyper-arid desert areas in northern and southern Africa in areas where drinking water could be found in ephemeral waterholes, oases, or subterranean water flows in dry riverbeds. For African elephants living in the desert and semi-desert habitats of southern Africa, acacia trees and baobabs provide elephants with life-sustaining forage resources. Acacia trees are critically important for elephants, because unlike most other types of African trees, virtually all parts of many acacia species are highly palatable and highly nutritious for elephants, including the leaves, flowers, branches, sapwood, bark, roots, seeds and seed pods. Mature acacia trees provide elephants with oases of shade and protection from the sun, without which they are subject to sunburn and hyperthermia. Elephants in turn are important to acacia trees in these habitats, because elephants provide the acacias whose seed pods they feed on with a efficient and effective vehicle for the dispersal of undigested seeds to new areas of potentially suitable habitat as much as 20-50km from the parent tree.In drought periods, however, African elephants living in desert and semi-desert regions are subject to high levels of mortality from thirst and starvation. Droughts have heavy impacts on trees as well as elephants, both directly and indirectly. Trees are stressed due to lack of water, and may shed their leaves early to conserve stored energy resources and minimize water loss to the atmosphere. Droughts can limit or curtail the production of fruits and seed pods from trees that constitute key nutrient resources for elephants during the late rainy season and dry season months. Elephant damage to mature acacia trees and baobabs can increase to catastrophic levels during severe droughts, because the annual grasses which comprise the bulk of the elephant’s diet during the rainy season periods are scarce or absent, and the only food resources available to elephants is plant material from perennial woody plant species, shrubs, and trees.We hope that this dance can inspire new insights into the marvelous beauty and complexity of Nature, and a greater appreciation and respect for the evolutionary history and evolutionary future of all life on this Earth.