Conserving Rivers

Chiredzi and Runde Rivers

The Chiredzi River forms the western boundary of Malilangwe, with the Hippo Valley Game Section on the opposite bank. Among Malilangwe’s 38 vegetation types, its riparian and aquatic habitats are among the most important because of the rich biodiversity and high concentration of wildlife they support.

The riverine forest along both banks provides valuable nesting habitat for species such as Pel’s fishing owl, black sparrowhawk, African hawk-eagle, African goshawk, crowned eagle, white-backed vulture, hooded vulture and Verreaux’s eagle-owl. Several of these birds are of significant conservation concern. The habitat also offers suitable nesting opportunities for lappet-faced and white-headed vultures, both of which are becoming increasingly rare in southern Africa.

Parrots, especially brown-headed parrots, are an increasing conservation priority in southern Africa because of pressure from the pet trade. At Malilangwe and in the Hippo Valley Game Section, their presence depends largely on the riparian habitat of the Chiredzi River, which provides both food and nesting sites. If this forest is degraded, the impact on these birds is likely to be severe. The river’s shallow pools and reed beds also support notable wetland species, including saddle-billed, woolly-necked and yellow-billed storks. More broadly, the riparian and aquatic habitats support at least 12 mammal species. During the wet season, the riverine zone is an especially important grazing area for elephant bulls, helping to reduce pressure on woody vegetation elsewhere. The Chiredzi River is also the main source of drinking water for wildlife in both Malilangwe and the Hippo Valley Game Section, particularly for large herds of buffalo and elephant whose water needs cannot be met by smaller artificial pans away from the river.

The Chiredzi River’s shallow pools and reed beds highlight the sensitivity of this ecosystem to disturbance. Any decline in the health of the river and its associated habitats would reduce the diversity of wildlife the area can support. One of the main ongoing pressures is polluted irrigation return flow from nearby sugar cane fields, which can affect water quality and reduce the abundance and diversity of macroinvertebrates. Because these organisms are a vital food source for many aquatic and semi-aquatic species, losses at this level can have far-reaching effects throughout the ecosystem. Improving irrigation efficiency and reducing polluted runoff would help safeguard the ecological integrity of the Chiredzi River and the biodiversity it sustains.