The Rufiji River in Tanzania serves as a vital stronghold for hippopotamus populations, offering one of East Africa’s most significant habitats for these massive semi-aquatic mammals. Flowing through the Selous Game Reserve (now Nyerere National Park), Africa’s largest protected wilderness, the river’s oxbow lakes and channels provide ideal conditions for hippo pods that can number up to 50 individuals. These territorial behemoths spend their days submerged in the river’s murky waters to protect their sensitive skin from the harsh African sun, emerging at dusk to graze on riverbank vegetation in spectacular displays of nighttime feeding activity that can last up to six hours.
The Rufiji’s hippos play a crucial ecological role as “landscape engineers” – their constant movement between water and land creates channels that shape the river’s flow, while their nutrient-rich dung fertilizes the aquatic ecosystem. Visitors to the Selous can observe these fascinating behaviors on boat safaris, where they’ll witness males establishing dominance through dramatic jaw-gaping displays and hear their distinctive deep grunts that carry across the water. The river’s hippo population remains relatively stable thanks to strict anti-poaching measures in the reserve, though they still face threats from habitat reduction during dry seasons and occasional human-wildlife conflict.
For the safest viewing experience, travelers should maintain respectful distances during boat excursions, as hippos are notoriously territorial and account for more human fatalities in Africa than any other large mammal. The best viewing occurs in the late afternoon when hippos become most active, with peak numbers visible during the dry season (June-October) as water sources contract. Conservation-focused lodges along the Rufiji like Siwandu and Serena Mivumo River Lodge offer expert-guided viewing opportunities while supporting protection efforts for these iconic river giants and their fragile aquatic habitat.