Before scientists had truly discovered and analyzed the okapi to determine its evolutionary origins and way of life, it was know as the "African Unicorn", mainly due to its elusive behavior and the fact that it was difficult for even native peoples to find or track in the dense rainforest. The okapi has evolved to near perfectly suit this ecosystem, it knows exactly where to find it's preferred food but is not limited by the species of food it can eat and its dark fur combined with the stripes on its rear and legs allow it to blend into its environment and avoid detection from its main predator.
Despite living within this type of environment and feeding on over 100 different species of plants, the okapi is selective in the types of plants it will eat. Okapi's prefer areas within the forest that have been partially cleared, usually treefall gaps, along stream beds, or other areas of secondary growth that break up the canopy of the forest and allow for light to penetrate the lower layers. Within these lighter areas heliophilic plants grow quickly and abundantly, they are the okapi's favorite type of food. Okapi have also been known to eat fruit and different types of fungi. Okapi take advantage of the forest's diversity of plant life but still maintain their very own niche of resources by choosing plants that are only found in a certain part of the forest.
Rainforests, as large and sprawling as they are, are divided into 4 vertical layers, the emergent, canopy, understory, and forest floor layers. The okapi inhabits the understory layer, a dark and humid layer of the forest filled with many shrubs and flowering plants located several meters below the canopy.
The thick undergrowth of this forest layer is a huge help when okapi calves are born, the young will often be left on their own for some time while the mother grazes, but they are safe as they can be, tucked away from prying eyes in the gloom of this undergrowth. This moist, damp environment is also perfect for the growth of different fungi and species of fern plants that the okapi will happily snack on if they are not able to find their preferred food source. Despite the dense foliage present throughout the forest, the okapi is able to navigate quite easily, usually following small forest trails that they are familiar with and communicating through low frequency calls in order to find each other.
Also comprising the many layers of a rainforest is the canopy, an often interwoven layer of tree branches, leaves, and fruit, among which a large variety of animals live and thrive.
In many ways the okapi benefits from these tall-growing trees, the shade they provide not only keeps the okapi from overheating but also provides the perfect environment in which to disappear and hide from it's main predator. The breaking up of sunlight as it streams through the gaps in the canopy creates an effect similar to the spots on a leopard or the stripes on an okapi, both are equally camouflaged by the dappling sunlight.
The okapi also uses these trees as scent markers to denote territory or let another know about their readiness to mate. Males will spray their urine on nearby trees and both sexes may rub their necks along the sides of the tree. Okapis can exude a brown substance from their skin by performing this act, it carries with it their scent and alerts other animals to their presence.
Many species, as they evolve and survive, form a multitude of relationships with the other organisms around them. Okapi's are not excluded from this, you've already seen how they benefit from the food and protection that the vegetation around them provides, well the plants also benefit from the okapi. The trees within okapi territories not only benefit from the fertilizer-like qualities of the okapi's excrement but also in the dispersal of the their seeds when the okapi eats their fruit and deposits it in another area of the forest. The okapi also benefits from the lives and migrations of bats within the area, when they need a few more nutrients that their diet just cannot provide they will consume bat guano out of the hollows of some trees.
The African leopard is a fierce carnivore that preys on the okapi and receives a valuable meal in return for killing the animal, obviously this doesn't truly benefit the okapi but it does go to show the back and forth of some of the forests symbiotic relationships. Even the clans of African Pygmies, the native peoples of central Africa's rainforests, benefit from the okapi as both an occasional food source and provider of other resources. For more information on some of the other organisms that live in the Congo rainforests you can click the button below.
References
Bodmer, R. E., & Rabb, G. B. (1992). Okapia johnstoni. Mammalian Species, 422, 1. https://doi.org/10.2307/3504153
Johnson, J. (2022, August 4). Rainforest. National Geographic. Retrieved January 31, 2023, from https://education.nationalgeographic.org/resource/rain-forest/
National Geographic. (n.d.). Okapi. National Geographic. Retrieved February 3, 2023, from https://www.nationalgeographic.com/animals/mammals/facts/okapi
Key Words: Heliophilic, Understory, Canopy, Exude, Guano, African Pygmies