The black rhinoceros, Diceros bicornis, is a critically endangered mammal found across parts of East and Southern Africa. Unlike its relative, the white rhinoceros, which primarily grazes on grasses, the black rhino is a browser, specializing in consuming woody vegetation.
Primary Food Sources
Black rhinos primarily consume a diverse range of woody plants, including shrubs, trees, and their components. Their diet encompasses leafy plants, tender twigs, branches, shoots, bark, and fruits. They can eat up to 220 different plant species, though their diet often focuses on a few key types. Common examples include various Acacia species and plants from the Euphorbia genus.
The specific composition of a black rhino’s diet changes considerably based on its habitat, the prevailing season, and the availability of plants. During drier periods, they might rely more on tougher plant parts like bark or roots, sometimes using their horns to dig up underground edibles. Their ability to digest fibrous and thorny vegetation is a notable adaptation, with their thick skin providing protection from sharp thorns. While primarily browsers, grasses typically form a very small portion of their diet, usually less than 5%, though they may consume newly emerging or green grass in certain regions.
Specialized Feeding Behavior
The black rhino’s feeding method is characterized by its distinctive prehensile upper lip, which is pointed and flexible. This specialized lip acts like a finger, allowing the rhino to grasp and pluck leaves, shoots, and twigs directly from branches with precision. This adaptation contrasts sharply with the broad, square lip of the white rhinoceros, which is better suited for sweeping up large quantities of grass from the ground. Without front incisor teeth, the black rhino relies heavily on its muscular lips to pull food into its mouth.
Black rhinos are selective eaters, prioritizing quality over quantity of forage. They might use their horns to break or knock down taller branches, making otherwise inaccessible foliage available. They also strip bark from branches and tree trunks. Rhinos spend a substantial portion of their day foraging, consuming up to 2.5% of their body mass daily, which can amount to 30 kilograms of plant material.
Ecological Impact of Their Diet
The browsing activities of black rhinos have a notable influence on the structure and composition of their ecosystems. By selectively feeding on shrubs and trees, they help to shape the vegetation patterns, which can create open pathways and clearings within dense bushland. This constant modification of plant growth impacts overall plant diversity within their habitat.
Black rhinos also contribute to ecological processes through seed dispersal. As they consume fruits and other plant parts, seeds pass through their digestive system and are deposited in their droppings, or dung. The dung acts as a natural fertilizer, enriching the soil and promoting the germination of new plants, aiding in forest regeneration. This role in shaping vegetation and distributing seeds underscores the black rhino’s position as a significant component within its environment.