Summary

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Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) are present in Okomu National Park.
The population size is unknown.
The population trend is unknown.
The site has a total size of 6,731 km².
Key threats to chimpanzees are logging, expansion of land for plantations, and human encroachment.
Conservation activities at the site have not been documented.

Site characteristics

Located in southwestern Nigeria, the site was upgraded from wildlife sanctuary to national park in 1999 (Nwankwo & Halilu 2020).

Table 1. Basic site information for Okomu National Park

Species	Pan troglodytes ellioti
Area	6,731km²
Coordinates	Lat: 6.252 , Lon: 5.268
Type of site	Protected area (National Park)
Habitat types	Subtropical/tropical moist lowland forest, Shrubland
Type of governance

Types of sites Governance types Habitat types

Ape status

Table 2. Ape population estimates reported for Okomu National Park

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						Okomu National Park

Sampling methods Analytical frameworks

Threats

Large-scale illegal logging (which has been going on since the 1950s) and the expansion of large rubber and oil-palm plantations nearby are the biggest threats to the park. About 50,000 people in 45 villages live in and around the park, and the population is increasing. Many are recent immigrants attracted by possibilities of employment in the timber and plantation industries, or by farming and hunting opportunities (BirdLife International 2020).

Conservation activities

Challenges

Table 5. Challenges reported for Okomu National Park

Challenges	Specific challenges	Source	Year(s)
	Not reported

Challenges

Enablers

Table 6. Enablers reported for Okomu National Park

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

Documented behaviours

Table 7. Behaviours documented for Okomu National Park

Category	Behavior	Observation type	Prevalence	Observation dates	Source	Habituation	Species	Comment
	Not reported

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 Okomu National Park

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	28.5	29.5
Annual precipitation [mm]	2338	2398	2415	2382	2440
Max no. consecutive dry days (per year)	31.2	34.9	34.799999999999997	34.9	38.1
No. days with heavy precipitation (per year)	6	9.8000000000000007	9.4	9.9	11.7

Table 9. Projected exposure of apes to extreme climate impact events in Okomu National Park

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	4	2.0699999999999998	1.5	1.57	2	2.0699999999999998	7.5	2.0699999999999998
Drought	0	0	0	0	0	0	0.25	25
Heatwave	10	100	10.5	100	10.5	100	12.5	100
River flood	2	2.92	2.25	1.43	2.25	3.06	4	6.32
Tropical cyclone	0	0	0	0	0	0	0.5	1.21
Wildfire	30	0.44	30	0.44	29	0.44	29	0.47

External links

References

BirdLife International. (2020). Important Bird Areas factsheet: Okomu National Park. Downloaded from http://www.birdlife.org on 19/10/2020.

Nwankwo, E. A. (2016). Sustainable Wildlife Conservation at Okomu National Park. Ottoman Journal of Tourism and Management Research, 1(1), 101-118. https://doi.org/10.26465/ojtmr.2016132258

Page created by: APES Atlas Team Date: 2020-12-02