Celebrating World Hippo Day: The environmental importance of hippos
February 15 is World Hippo Day, a day to celebrate the majestic animal and encourage people to take action against its extinction. As a result of poaching, loss of access to fresh water, mechanized farming, and urbanization, only about 115,000 – 130,000 hippos are left in the wild. The common hippo and the pygmy hippo are listed as Vulnerable and Endangered on the IUCN Red List.
Without hippos, certain fish species and algae populations will be reduced, which can lead to food shortages in African water bodies, including Lake Victoria. Let’s explore the environmental importance of hippos and why we can’t afford to let them go extinct.
Hippos spend about 16 hours of the day submerged in the water, whether it be in rivers, lakes, muddy waters, or wetlands. They wait until sunset to emerge onto land and feed. When eating, they will feast on foliage and short grass (called hippo lawns), eating up to 35kg in one sitting. They can hear the sounds of falling fruit, and their good smell helps them sniff out the fruits.
Frequent grazing of the foliage and short grasses enables the plants to grow stout and leafy, benefiting the hippos and the local environment. Researchers found that grassy areas where hippos didn’t frequent were more strawy and blossomed more often.
What comes out of the hippo is also highly beneficial to the environment surrounding them. Hippos habitually rotate their tails like a propeller when they defecate. This spreads their dung around both in and out of the water.
Hippo dung is full of nutrients, including nitrogen, carbon, and phosphorus; these nutrients promote the growth of living things within the food web and stimulate algae growth and other microorganisms.
Their dungs also act as a natural fertilizer, often carried downstream by currents, which benefits flora and fauna along the riverbanks. The hippo dung will result in nutrient hotspots, promote vegetation growth, and foster diverse habitats for other animals, which helps enhance biodiversity in these areas. The rate of absorption is highest during the dry season when the organic matter is more readily available as it is not as easily diluted by fast-flowing waters.
Hippo’s day-to-day activity of laying in the water also contributes to local ecosystems. Their wallowing creates depressions in riverbeds and forms small pools. These small pools will shelter other aquatic organisms, including plants, invertebrates, and fish, during dry seasons when water levels recede and ensure survival during harsh conditions.
If hippos were to disappear, the effect would be catastrophic and would cause irreparable damage to the entire ecosystem. Without hippos, the water will be impacted, causing a drop in insect and fish numbers and decreasing the number of birds, bats, snakes, and spiders in this area. Moreover, the people who depend on the fish and animals in these areas will be impacted.
The environmental importance of hippos is clear, and we must take the necessary measures to protect hippos not only on World Hippo Day but every day.
Here are a few ways you can celebrate this day:
- Learn more about hippos, their behaviours, habitat, and conservation status.
- See a hippo at your local zoo or wildlife sanctuary.
- Celebrate World Hippo Day.
- Watch a film featuring hippos (Madagascar, Fantasia).
- Make a donation to an animal conservation organization (the World Wildlife Foundation).
- Support responsible tourism by choosing ethical operators when participating in an African safari to see a hippo in its natural environment.
No matter how you celebrate World Hippo Day, it is one step closer to protecting these incredible animals and the ecosystems that depend on them.
