Semliki River (sometimes Semuliki) is a major river, 140 kilometres (87 mi) long, in the Democratic Republic of the Congo (DRC) and Uganda in Central and East Africa. It flows north from Lake Edward to Lake Albert in the Albertine Rift west of the Rwenzori Mountains. Along its lower reaches, it forms part of the international border between the DRC and the western Ugandan district of Bundibugyo, near the Semuliki National Park. It empties into Lake Albert slightly west of the border in Orientale Province of the DRC.
Increasing snowmelt from the Rwenzoris, overgrazing, and other alterations to the watershed have caused bank erosion and frequent changes to the course of the meandering lower reaches of the river. In some places, Uganda is losing up to 10 metres (33 ft) of land per year on its side of the river to erosion, and silt from the Semliki is gradually filling in the southern end of Lake Albert. In other places, it is the DRC that is losing territory as the changing river course alters the apparent location of the border.
Flora and fauna:
In Semuliki National Park, the forest resembles that of the Congo River basin. Cynometra alexandri, a tropical tree species, dominates but is interspersed with other trees and swamp flora. Annual rainfall in this tropical forest averages 1,500 millimetres (59 in).
More than 400 bird species, including the forest ground-thrush, Sassi's olive greenbul, and nine species of hornbill frequent the park, as do many kinds of Charaxes butterflies. Among the mammals in the park are elephants, buffalo, hippopotami, duikers, and pygmy flying squirrels.