Ohosu Forest Reserve
Summary
- Nigeria-Cameroon chimpanzees (Pan troglodytes ellioti) are likely absent in Ohosu Forest Reserve.
- The population size is unknown.
- The chimpanzee population trend is decreasing (likely extinct).
- The site has a total size of 471 km².
- Key threats to chimpanzees are habitat degradation due to logging and farming.
- Conservation activities are not documented.
Site characteristics
Ohosu Forest Reserve is located in Edo State, bordering both Akure-Ofosu and Idanre Forest Reserves in Ondo State. The Lagos-Benin expressway lies close to its southern border (Greengrass 2006).
Table 1. Basic site information for Ohosu Forest Reserve
| Area | 471 km² |
| Coordinates | |
| Designation | Forest Reserve |
| Habitat types | subtropical/tropical heavily degraded forest, subtropical/tropical moist lowland forest |
Ape status
Based on a 2006 survey, it is likely that chimpanzees have gone extinct in the reserve. Local people reported that large-scale logging activity in the reserve caused chimpanzees to migrate north into Ondo state. One man reported not seeing chimpanzees since the early 90s (Greengrass 2006).
Table 2. Ape population estimates in Ohosu Forest Reserve
| Species | Year | Abundance estimate (95% CI) | Density estimate [ind./ km²] (95% CI) | Encounter rate (nests/km) | Area | Method | Source | Comments | A.P.E.S. database ID |
|---|---|---|---|---|---|---|---|---|---|
| Pan troglodytes ellioti | 2006 | 0 | Ohosu Forest Reserve | Index survey (reconnaissance walk) | Greengrass 2006 |
Threats
Timber exploitation was intense in this reserve, and there have also been many illegal farm settlements in the site.
Table 3. Threats to apes in Ohosu Forest Reserve
| Category | Specific threats | Threat level | Quantified severity | Description | Year of threat |
|---|---|---|---|---|---|
| 1. Residential & commercial development | Unknown | ||||
| 2. Agriculture & aquaculture | 2.1 Annual & perennial non-timber crops | High | Illegal farming in the reserve (Greengrass 2006). | Ongoing (2006) | |
| 3. Energy production & mining | Unknown | ||||
| 4. Transportation & service corridors | Unknown | ||||
| 5. Biological resource use | 5.3 Logging & wood harvesting | High | Timber exploitation that was reported as early as 1982 (Greengrass 2006). | Ongoing (2006) | |
| 6. Human intrusion & disturbance | Unknown | ||||
| 7. Natural system modifications | Unknown | ||||
| 8. Invasive & other problematic species, genes, diseases | Unknown | ||||
| 9. Pollution | Unknown | ||||
| 10. Geological Events | Absent | ||||
| 11. Climate change & severe weather | Unknown | ||||
| 12. Other options | Absent |
Conservation activities
Table 4. Conservation activities in Ohosu Forest Reserve
| Category | Specific activity | Description | Year of activity |
|---|---|---|---|
| 1. Residential & commercial development | Not reported | ||
| 2. Agriculture & aquaculture | Not reported | ||
| 3. Energy production & mining | Not reported | ||
| 4. Transportation & service corridors | Not reported | ||
| 5. Biological resource use | Not reported | ||
| 6. Human intrusion & disturbance | Not reported | ||
| 7. Natural system modifications | Not reported | ||
| 8. Invasive & other problematic species, genes, diseases | Not reported | ||
| 9. Pollution | Not reported | ||
| 10. Education & Awareness | Not reported | ||
| 11. Habitat Protection | Not reported | ||
| 12. Species Management | Not reported | ||
| 13. Livelihood; Economic & Other Incentives | Not reported |
Challenges
Table 5. Challenges reported for Ohosu Forest Reserve
| Challenge | Source |
|---|---|
| Not reported |
Research activities
Documented behaviours
Table 6. Ape behaviors reported for Ohosu Forest Reserve
| Behavior | Source |
|---|---|
| Not reported |
External links
References
Greengrass, E.J. (2006). A survey of chimpanzees in south-west Nigeria. Report to the NCF-WCS Biodiversity Research Programme.
Page completed by: A.P.E.S. Wiki team Date: 13/03/2023