Elephants interact in dramatic and complex ways with whole landscapes and ecosystems. Confinement of elephants may have multifaceted environmental consequences for both elephants and the species with which they share their natural space. Equally, their removal from ecosystems can have multifaceted environmental consequences.
We have an obligation to maintain the integrity of ecosystems that elephants inhabit, and must take realistic account of the needs of elephants in the planning and management of protected areas and landscapes.
- Elephants live, or have lived, in virtually every habitat type on the African and Asian continents ranging from sea level to 3000 metres, from sub-deserts to swamps, lowland rainforests, gallery and montane forests, upland moors, floodplains, savannas, and various types of woodlands.
- Shade, cover for protection, and water availability, can have important impacts on elephant movements and distribution.
- Preferred elephant habitat provides for browsing, grazing, and access to water, but in rare cases elephants have adapted to desert conditions, where they cope with seasonally scarce vegetation and water by utilizing vast home ranges (up to 11 000 sq km) including seasonal migrations up to 650 km.
- Several anatomical, physiological and behavioral adaptations allow elephants to survive very harsh environments, including the ability to go without water for several days and the ability to cool their bodies by placing the trunk into the pharyngeal pouch at the back of the throat, extracting water therein and spraying it over the back, under-body and ears.
- Elephants tend to be found at higher densities in mixed woodlands, with year round grass and browse, and are at lower densities in dense moist forest and open grasslands. They are least common at high altitudes and in hot deserts, where access to water is limited.
- Elephants can exploit fruits and herbaceous and woody vegetation. They may switch seasonally between grass-dominated or browse-dominated diets, and seasonal movement patterns through different habitats reflect attempts to achieve the most nutritious diets in any given time or place. While they do well on an entirely browse diet or a mixed browse and grass diet, no elephant population has been observed to thrive on an entirely grass diet.
- Due to their large size and digestive system specialized for rapid throughput of coarse vegetation, elephants are adapted to a lifetime of foraging; feeding for 60-70% of a 24-hour day, they consume 150-450 kg, or six to eight percent of their body weight. An adult elephant must drink an average of 100-160 litres per day.
- In the past, the elephant-habitat relationship in drier regions was probably spatially dynamic, influenced by climatic variation and succession patterns that involved other herbivores and, quite possibly, Pleistocene hunter-gatherers, and in more recent millennia, modern humans. In moist forest there was possibly greater stability in this interaction.
- Elephants interact in complex ways with whole landscapes and ecosystems; they have been referred to as a “keystone species” in reference to the important role they play in shaping the structure and functioning of plant and animal communities. Vegetation change caused by elephants, often in combination with other ecological drivers such as fire or water table variation, is a normal activity and can contribute to positive changes in habitat diversity and biomass turnover. However, since mobility and dispersal are important factors in the natural self regulation of elephant populations, the confinement and concentration of elephants in small or fenced ranges can lead to elevated densities, with changes in the landscape that can reduce local species diversity.
- In protected areas, locally high abundance of elephants may occur when there is human disturbance – to which elephants are keenly sensitive – or blockage of movement patterns. As noted, artificially confined elephants may cause dramatic changes in habitats, and it has been argued that such populations must be reduced or limited. Blocking dispersal reduces the options for management to interventive methods including translocation, contraception and culling, all of which pose ethical dilemmas.