Rio Muni
Summary
- Central chimpanzees (Pan troglodytes troglodytes) & western lowland gorillas (Gorilla gorilla gorilla) are present in Rio Muni.
- It has been estimated that 11,097 (CI: 8,719–13,592) great apes occur in the site.
- The great ape population trend is unknown.
- The site has a total size of 26,017 km².
- Key threats to great apes are extensive commercial hunting, expansion of roads, and human encroachment.
- Conservation activities are not documented.
Site characteristics
Río Muni, the mainland region of Equatorial Guinea, is bordered by Cameroon to the north, and Gabon to the east and south. The area covers 26,017 sq. km; vegetations largely consists of Guineo-Congolian rainforest, mangrove forests in the southwest estuary, riparian palm forests along the coast, and some inselbergs in the east (Murai et al. 2013).The region has rich faunal diversity that includes gorillas, chimpanzees, various monkeys, leopards, buffalo, antelope, elephants, hippopotamuses, crocodiles, and various snakes, including pythons (Britannica).
Table 1. Basic site information for Rio Muni
| Area | 26,017 km² |
| Coordinates | 1.700144 N, 10.472875 E |
| Designation | Unclassified |
| Habitat types | Subtropical/tropical mangrove vegetation above high tide level, subtropical/tropical moist lowland forest, subtropical/tropical moist montane forest |
Ape status
The estimated great ape population in 2011 was 11,097, including a maximum population of 7,824 chimpanzees and a minimum population of 3,273 gorillas (Murai et al. 2013).
Table 2. Ape population estimates in Rio Muni
| 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 |
|---|---|---|---|---|---|---|---|---|---|
| Gorilla gorilla gorilla & Pan troglodytes troglodytes | 2011 | 11,097 (8,719–13,592) | Río Muni | Line transects (Distance) | Murai et al. 2013 | Survey effort: 233.94 km |
Threats
The expansion of roads across the region have facilitated heavy commercial hunting, which is in high demand with increasing population and wealth (Murai et al. 2013).
Table 3. Threats to apes in Rio Muni
| Category | Specific threats | Threat level | Quantified severity | Description | Year of threat |
|---|---|---|---|---|---|
| 1. Residential & commercial development | 1.1 Housing & urban areas | High | In a 2013 study, proximity to cities and settlements were the strongest predictors of ape density, which decreased closer to human centres (Murai et al. 2013). | Ongoing (2013) | |
| 2. Agriculture & aquaculture | 2.1 Annual & perennial non-timber crops | Medium | Great apes densities have been shown to negatively correlate with agricultural mosaic habitat (Murai et al. 2013). | Ongoing (2013) | |
| 3. Energy production & mining | Unknown | ||||
| 4. Transportation & service corridors | 4.1 Roads & railroads | High | Expansion of the road network across the region facilitates commercial hunting and deforestation (Murai et al. 2013). | Ongoing (2013) | |
| 5. Biological resource use | 5.1 Hunting & collecting terrestrial animals | High | Extensive commercial hunting and large urban bushmeat markets in the region (Murai et al. 2013). | Ongoing (2013) | |
| 5.3 Logging & wood harvesting | High | Forest concessions significantly increased since the discovery of oil reserves in the early 1990s; by 2001, forest concessions covered 1.7 million hectares (Murai et al. 2013). | Ongoing (2013) | ||
| 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 Rio Muni
| 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
Protected areas in Río Muni cover 15.4% of the country’s land, but there are limited law enforcement activities undertaken to manage and protect these areas (Murai et al. 2013).
Table 5. Challenges reported for Rio Muni
| Challenge | Source |
|---|---|
| Lack of law enforcement | Murai et al. 2013 |
Research activities
Determinants of urban bushmeat consumption in Río Muni, Equatorial Guinea
Documented behaviours
Table 6. Ape behaviors reported for Rio Muni
| Behavior | Source |
|---|---|
| Not reported |
External links
Relevant datasets
References
Murai M, Ruffler H, Berlemont A, Campbell G, Esono F, Agbor A, et al. (2013) Priority Areas for Large Mammal Conservation in Equatorial Guinea. PLoS ONE 8(9): e75024. https://doi.org/10.1371/journal.pone.0075024
Page completed by: A.P.E.S. Wiki team Date: 14/01/2021