Summary

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Nigeria-Cameroon chimpanzees (Pan troglodytes ellioti) are present in Ise Forest Reserve.
The population size is unknown; in 2006 at least 5 individuals occurred in the reserve.
The chimpanzee population trend is decreasing.
The site has a total size of 62 km².
Key threats to chimpanzees are logging and hunting.
Conservation activities are not documented.

Site characteristics

Ise Forest Reserve is a small reserve in Ekiti State, Nigeria.

Table 1. Basic site information for Ise Forest Reserve

Species	Pan troglodytes ellioti
Area	62 km²
Coordinates	Lat: 7.393197 , Lon: 5.382600
Type of site	Protected area (Forest Reserve)
Habitat types	Subtropical/tropical heavily degraded forest
Type of governance

Types of sites Governance types Habitat types

Ape status

In 2006, the eastern side of the reserve, composed of regenerated forest, was surveyed. Chimpanzees were regularly heard and sighted. Reports of sightings of 4-6 individuals and the presence of two nesting sites with 5 nests each, suggests that at least 5 individuals inhabit the area; it is probable that the site could support 10 or more individuals (Greengrass 2006). However, the population trend is decreasing due to high hunting pressure and habitat degradation caused by logging activities (Greengrass 2006).

Table 2. Ape population estimates reported for Ise 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				Ise Forest Reserve, eastern side	Reconnaissance walk		Greengrass 2006	2 nesting sites observed, with 5 nests each.

Sampling methods Analytical frameworks

Threats

High hunting and logging pressure are the main threats to chimpanzees in the reserve. Relative to nearby protected areas, Ise forest reserve has been less impacted by logging and agriculture. However, these threats are increasing, putting wildlife and chimpanzees in the reserve at greater risk (Greengrass 2006).

Table 3. Threats to apes reported for Ise Forest Reserve

Category	Specific threats	Threat level	Description	Year of threat
5 Biological resource use	5.1 Hunting & collecting terrestrial animals	High (more than 70% of population affected)	High hunting pressure; for instance, in 2005 a chimpanzee mother was killed and her baby captured (Greengrass 2006).	Ongoing (2006)
5 Biological resource use	5.3 Logging & wood harvesting	High (more than 70% of population affected)	Logging pressure is intense and increasing (Greengrass 2006).	Ongoing (2006)

Threats

Conservation activities

Challenges

Table 5. Challenges reported for Ise Forest Reserve

Challenges	Specific challenges	Source	Year(s)
	Not reported

Challenges

Enablers

Table 6. Enablers reported for Ise 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

Documented behaviours

Table 7. Behaviours documented for Ise Forest Reserve

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. (2024) 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 (Kiribou et al. 2024).

Table 8. Estimated past and projected climatological characteristics in Ise 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]	25.9	27	26.8	27.2	28.2
Annual precipitation [mm]	1494	1504	1516	1484	1539
Max no. consecutive dry days (per year)	40.6	46.7	48.3	48.1	51.6
No. days with heavy precipitation (per year)	5.9	8.9	8.8	9	9.8

Table 9. Projected exposure of apes to extreme climate impact events in Ise 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	4.5	0.58	4.5	1.03	4	1.3	11.5	1.12
Drought	0	0	0	0	0	0	0	0
Heatwave	3	100	2.5	100	1.5	100	5.5	100
River flood	0.75	0.02	1.25	0.12	0.5	0.11	2	0.16
Tropical cyclone	0	0	0	0	0	0	0	0
Wildfire	30	0.74	30	0.73	29	0.71	29	0.88

Precipitation anomaly in Ise Forest Reserve
Temperature anomaly in Ise Forest Reserve

External links

References

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

Kiribou, R., Tehoda, P., Chukwu, O., Bempah, G., Kühl, H. S., Ferreira, J., …, & Heinicke, S. (2024). Exposure of African ape sites to climate change impacts. PLOS Climate, 3(2), e0000345. doi:10.1371/journal.pclm.0000345

Page created by: APES Atlas Team Date: 2023-03-03