The forest zone around Semuliki is a zone of exceptional biological variety. This is a result of its forest age, stable climatic conditions, and transitional geographic position. The park supports over 336 tree species, many of which are limited to central African rainforests.
This vegetative complexity creates habitat for a range of faunal species. The park supports over 60 known mammal species, including forest buffalo, sitatunga, bushbuck, and small primates such as De Brazza’s monkey. Insect diversity is pronounced, particularly within the Lepidoptera and Coleoptera families.
The site is also a key regional birding zone. Over 440 bird species have been recorded, including 46 Guinea–Congo biome species not found elsewhere in East Africa.
Though complete listings are managed under separate bird-monitoring programmes, the park holds confirmed populations of Nkulengu rail, long-tailed hawk, and black dwarf hornbill. Some species are confined to specific microhabitats such as riverine edges or the upper canopy.
C. Forest Trails and Research Zones
Semuliki contains several maintained forest trails used for ecological interpretation and scientific access. The Kirumia Trail is the longest-established route.
It covers approximately 13 kilometres through central forest blocks and reaches the Semliki River floodplain. The Red Monkey Trail follows the eastern edge of the park and is used for targeted primate observation.
Trails are demarcated but unpaved. Their primary use is for ecological monitoring and low-impact visitor interpretation.
Conditions vary seasonally depending on rainfall and leaf litter density. The Uganda Wildlife Authority recommends guide accompaniment for all trail access, including for research permit holders.