What does the Common Hippo eat?
Common hippos are mostly grazers, and preferences are grasses such as Bothriochloa sp. , Bracharia decumbens, Chloris gayana, Cynodon dactylon, Heteropogoncontortus, Hyparrhenia flipendula, Sporobolus pyrimidialis and Themedatriandra.
In St Lucia, KwaZulu–Natal, Common Hippos eat fairly large quantities of Water Lilies –Nymphaea cerulean and the submerged macrophytes – Ruppia cirrhosa and Potamogeton pectinatus . In the plain of L. Rutanzige in Virunga N.P., Democratic Republic of Congo, when dry season grasses can’t produce a sufficient amount of crude protein, common hippos have been observed to feed on aquatic vegetation.
Foraging strategies respond to vegetation characteristics, such as vegetation quality, as well as spatial information, including distance to a water source. Because of their wide, square muzzle, they feed selectively with respect to individual plant species, but they do select the swards to a certain extent.
The weights of stomach contents are remarkably low and have been determined at ca. 1 percent dry weight, and only 50 percent of that of other large herbivores. The stomach contains two nights of intake and the daily intake is around 20 kg of dry weight.
Where they occur at high densities, common hippos shape the environment. The heavy grazing pressure reduces the amount of combustible material, thereby suppressing grass fires and enhancing the spreading of bushes. This will in turn lead to a reduction in grazing area and ultimately a reduction in the number and density of common hippos.
Reduced grazing will result in higher grass growth, fires will spread, bushes and trees will be burnt and destroyed, grassland expand, and Common Hippo numbers increase again. In swamps, the Common Hippopotamus can alter water flow, as on the banks of the Santa Lucia. Hippos, movements create and keep the deep, clear channels through the reeds and allow a freer flow of water. In back swamp areas, pathways lead to the development of new channel systems during channel avulsion.
Very rarely, common hippos have been observed to kill antelopes such as Impala – Aepyceros melampus and common wildebeest – Connochaetus taurinus and cattle, and also to scavenge from them and even from the cadavers of conspecifics. The likely explanation is a mineral deficiency in the ‘normal’ diet.
Licking the skin of conspecifics may have the same cause. Young animals have the habit of eating the dung of conspecifics; this also occurs in other ungulates and is thought to be the transmission mechanism of gut symbionts.
Adults have also been known to feed on elephant dung, suggesting that the plant is partially digested material and is an important forage resource for common hippos in times of drought. By defecating in water, hippos fertilize. They are thus causal for the vast harvests of fish, for example, of Lakes George and Edward in Uganda and DR Congo.
What does the Pigmy Hippo eat?
Pygmy hippos consume a wide variety of herbaceous materials (scissors, sedges, ferns, and fallen fruit). The food spectrum is broad and consists mainly of herbs and fruits. Food preferences varied among individuals, and some ferns and monocots were readily consumed by all captured animals.
Their favorite food is high in sodium. Captive diets frequently consist of green leafy vegetables, lucerne, grass hays, carrots, apples, oats, bread, and supplements of trace minerals and alpha-tocopherol. A small climbing herb (Geophila sp.), is a preferred food throughout Liberia.
They do not appear to eat aquatic vegetation or animal matter in the wild. Dung piled up and tail splattered droppings are commonly found along with the vegetation along the trail. They very occasionally consume crops during wet seasons in remote agricultural areas but are not considered crop pests. They have been observed standing on their hindlegs (with their front legs against the stem) to reach ferns growing within Raphia palms.