Summary

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Nigeria-Cameroon chimpanzees (Pan troglodytes ellioti) are present in Oluwa Forest Reserve.
The population size is unknown.
The chimpanzee population trend is unknown.
The site has a total size of 678 km².
Key threats to chimpanzees are hunting, logging, and expansion of land for agriculture.
The site is part of the Omo-Shasha-Oluwa project, implemented by the Nigerian Conservation Foundation, which aims to connect three forest reserves and manage them as a wildlife sanctuary.

Site characteristics

Table 1. Basic site information for Oluwa Forest Reserve

Species	Pan troglodytes ellioti
Area	678 km²
Coordinates	Lat: 6.823 , Lon: 4.674
Type of site	Protected area (Forest Reserve)
Habitat types	Subtropical/tropical moist lowland forest, Agricultural land
Type of governance

Types of sites Governance types Habitat types

Ape status

In 2006, chimpanzees and signs of chimpanzees (nests and vocalizations) were observed by the Owena river in the core area of the reserve (Greengrass 2006). Similarly, in 2012 the distribution of chimpanzees was confined to the core area of the reserve (segment OA2), encompassing approximately 39.22 km², or 5.78% of the total forest reserve (Ogunjemite & Olaniyi 2012). The population trend is unknown.

Table 2. Ape population estimates reported for Oluwa Forest Reserve

Species	Year	Occurrence	Encounter or vistation rate (nests/km; ind/day)	Density estimate [ind./ km²] (95% CI)	Abundance estimate (95% CI)	Survey area	Sampling method	Analytical framework	Source	Comments	A.P.E.S. database ID
Pan troglodytes ellioti	2006	Present				Oluwa Forest Reserve	Reconnaissance walk		Greengrass 2006	Reconnaissance walk. Nests and individuals were seen in the core area of the reserve.Vocalizations and nests also observed.
Pan troglodytes ellioti	2011-2012	Present				Oluwa Forest Reserve	Reconnaissance walk		Ogunjemite & Olaniyi 2012	Reconnaissance walk. The study recorded 9.50 ± 1.55 individuals and 13 nests. Vocalizations and footprints were also documented.

Sampling methods Analytical frameworks

Threats

Table 3. Threats to apes reported for Oluwa Forest Reserve

Category	Specific threats	Threat level	Description	Year of threat
2 Agriculture & aquaculture	2.1 Annual & perennial non-timber crops	High (more than 70% of population affected)	Cultivation began from the outer edges of the reserve; only the core area has some natural forest left (Greengrass 2006, Ogunjemite & Olayimi 2012).	2006-Ongoing (2012)
5 Biological resource use	5.1 Hunting & collecting terrestrial animals	High (more than 70% of population affected)	Hunting is a major threat in the area; several gunshots were heard during a survey in 2006 (Greengrass 2006, Ogunjemite & Olayimi 2012).	Ongoing (2012)
5 Biological resource use	5.3 Logging & wood harvesting	High (more than 70% of population affected)	Logging activity on the eastern side of the Owena River, where chimpanzees were observed (Greengrass 2006).	Ongoing (2012)

Threats

Conservation activities

Together with Omo and Shasha forest reserves, Oluwa is part of the Omo-Shasha-Oluwa project, implemented by the Nigerian Conservation Foundation, which aims to connect the three areas (PNI 2011). Although Omo and Shasha reserves are connected, Oluwa forest is isolated. The plan is to manage the Omo-Shasha-Oluwa areas as a wildlife sanctuary and permit human use where it is compatible with forest conservation. Other conservation activities included in the plan are the re-gazettement of forest reserve areas, community development, environmental education, research, eco-tourism, and long-term financing through REDD carbon credits (PNI 2011). Further information on the advancement of these activities has not been reported.

Challenges

Table 5. Challenges reported for Oluwa Forest Reserve

Challenges	Specific challenges	Source	Year(s)
	Not reported

Challenges

Enablers

Table 6. Enablers reported for Oluwa Forest Reserve

Enablers	Specific enablers	Source	Year(s)
1 Site management
2 Resources and capacity
3 Engaged community
4 Institutional support
5 Ecological context
6 Safety and stability

Enablers

Research activities

A new nesting behavior was observed in the Oluwa Forest Reserve chimpanzee population during a survey in 2011-2012 (Ogunjemite & Olaniyi 2012). The majority of nests were built on rock platforms, perhaps due to the absence of tree species that are usually used for nesting (Ogunjemite & Olaniyi 2012).

Documented behaviours

Table 7. Behaviours documented for Oluwa Forest Reserve

Category	Behavior	Observation type	Prevalence	Observation dates	Source	Habituation	Species	Comment
	Making ground nests				Ogunjemite & Olaniyi 2012

Behaviours

Exposure to climate change impacts

As part of a study on the exposure of African great ape sites to climate change impacts, Kiribou et al. subm. extracted climate data and data on projected extreme climate impact events for the site. Climatological characteristics were derived from observation-based climate data provided by the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP, www.isimip.org). Parameters were calculated as the average across each 30-year period. For 1981-2010, the EWEMBI dataset from ISIMIP2a was used. For the two future periods (2021-2050 and 2071-2099) ISIMIP2b climate data based on four CMIP5 global climate models were used. For future projections, two Representative Concentration Pathways (RCP) were used. RCP 2.6 is a scenario with strong mitigation measures in which global temperatures would likely rise below 2C. RCP 6.0 is a scenario with medium emissions in which global temperatures would likely rise up to 3C by 2100. For the number of days with heavy precipitation events, the 98th percentile of all precipitation days (>1mm/d) was calculated for the 1979-2013 reference period as a threshold for a heavy precipitation event. Then, for each year, the number of days above that threshold was derived. The figures on temperature and precipitation anomaly show the deviation from the mean temperature and mean precipitation for the 1979-2013 reference period.

The estimated exposure to future extreme climate impact events (crop failure, drought, river flood, wildfire, tropical cyclone, and heatwave) is based on a published dataset by Lange et al. 2020 derived from ISIMIP2b data. The same global climate models and RCPs as described above were used. Within each 30-year period, the number of years with an extreme event and the average proportion of the site affected were calculated (see Kiribou et al. subm. for details).

Table 8. Estimated past and projected climatological characteristics in Oluwa Forest Reserve

Value	1981-2010	2021-2050, RCP 2.6	2021-2050, RCP 6.0	2071-2099, RCP 2.6	2071-2099, RCP 6.0
Mean temperature [C]	27.2	28.3	28.1	28.4	29.5
Annual precipitation [mm]	1833	1851	1890	1873	1907
Max no. consecutive dry days (per year)	40.4	39.2	37	37.4	41.9
No. days with heavy precipitation (per year)	6.1	9.6	10.2	10.2	11.3

Table 9. Projected exposure of apes to extreme climate impact events in Oluwa Forest Reserve

Type	No. of years with event (2021-2050, RCP 2.6)	% of site exposed (2021-2050, RCP 2.6)	No. of years with event (2021-2050, RCP 6.0)	% of site exposed (2021-2050, RCP 6.0)	No. of years with event (2070-2099, RCP 2.6)	% of site exposed (2070-2099, RCP 2.6)	No. of years with event (2070-2099, RCP 6.0)	% of site exposed (2070-2099, RCP 6.0)
Crop failure	3	2.84	1	0.73	1	2.93	3.5	2.93
Drought	0	0	0	0	0	0	0	0
Heatwave	10	100	11	100	10	100	13	100
River flood	0.5	0.54	0.5	0.18	0.5	0.4	2.5	0.99
Tropical cyclone	0	0	0	0	0	0	0.5	0.03
Wildfire	30	0.44	30	0.47	29	0.44	29	0.46

External links

References

Greengrass, E.J. (2006). A survey of chimpanzees in south-west Nigeria. Report to the NCF-WCS Biodiversity Research Programme.

Ogunjemite, B.G. and Olaniyi, O.E. (2012), “The chimpanzees of Oluwa Forest

Reserve, southwest Nigeria”, International Journal of Development and Sustainability, Vol. 1 No. 3, pp.

Pro-Natura International. (2011), Project Progress Report for the International Elephant Foundation January 2010 – May 2011.

Page created by: APES Atlas Team Date: 2020-11-19