The hippopotamus is widely distributed throughout sub-Saharan Africa but its range is now highly fragmented. The only other living species of hippopotamid, the pygmy hippopotamus, is found only in a few scattered locations in Liberia, Guinea, Sierra Leone, and Coté d’Ivoire.
The word “Hippopotamus” is derived from Greek and means “River horse.” The Fante word for hippopotamus is “Nsusun,” which means “Water elephant.” In fact hippopotamids are not closely related to either horses or elephants. Traditionally they have been grouped in the Order Artiodactyla, or even-toed hoofed mammals, but studies of nuclear DNA, mitochondrial DNA, and fossils all indicate that their closest relatives are not their fellow hoofed mammals at all, but rather the Order Cetacea, which comprises the whales, including the dolphins. The last common ancestor of hippopotamids and whales is believed to have lived some 55-60 mya.
The oldest known stem-group hippopotamid fossil is Elomeryx, which lived some 40 million years ago and was 1.5 meters long, about the size of a modern-day pig or tapir.
Anthracotherium, which arose about 33 million years ago, was about the same size as a modern hippopotamus, although with a much narrower head.
Bui National Park, located along the Black Volta River, is one of two remaining places in Ghana where hippos can be seen in their wild state. (The other is Weichiau Community Hippo Sanctuary in the Upper West Region.) The park contains the Bui Dam, constructed by Sinohydro Corporation of China. Filling of the reservoir commenced last July, and the hydroelectric power plant is expected to begin operating next year.
Accompanied by my wife Yaa, I traveled to Bui National Park in Ghana’s Northern region in hope of viewing some of these great beasts. We arrived mid-afternoon and, after settling in our accommodations, hiked to the summit of Kre Wura along with some American students taking a break from their labors at the University of Legon. This is the largest animal we saw:
Fortunately, the paucity of wildlife was somewhat compensated by the panoramic 360° view afforded us.
On the way down, we noticed a whole swarm of dragonflies dogging our every step. They definitely were following us. When we stopped, they stopped and hovered; when we started again, so did they.
Scientists have long known that mosquitoes are attracted to our scent. Since dragonflies eat mosquitoes, it makes sense that they should be attracted as well. I wonder if anyone has ever investigated this?
The next day we were up before dawn in hopes of finding Nsusun. Accompanied by park employees Peter, Ebenezer, and Isaac, we set off.
Peter told us that the park contains some 430 hippos. He added that the flooding of the valley has greatly increased their available habitat but ironically has made them all that much harder to find, by scattering them over a wider area.
We passed by the top of trees almost completely submerged by the advancing waters.
Then we stopped at one of the reservoir's many islands to take in the view.
After that it was back to the search.
We stopped to offer two fishermen a tow back to the boat launch, a favor for which they were extremely grateful.
We didn’t see any hippos. After a couple of hours we pulled up at the boat landing and disembarked.
By late afternoon we were back in Kumasi at the house of our sister Beatrice where she stays with our nephew Pa Ko (called P.K.) and our grand-nephew Papa Tetchie.
You don’t always find what you're looking for, but sometimes it’s important to make the search anyway, just so you can see what you had all along was enough.
Elomeryx skeleton illustration courtesy of Phillip D Gingerich
Anthracotherium illustration via Wikimedia Commons
All other photos by author