Summary

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Eastern chimpanzees (Pan troglodytes schweinfurthii) are present in Semuliki National Park.
It has been estimated that 50 (CI: 43-57) individuals occur in the site.
The chimpanzee population trend is unknown.
The site has a total size of 220 km².
Key threats to chimpanzees are habitat encroachment, poaching, and illegal harvest of forest products.
Conservation activities are not reported.

Site characteristics

Semuliki National Park is located in western Uganda, in the Albertine Rift valley, bordering the Democratic Republic of Congo (DRC) and Virunga National Park. The Lamia and Semliki rivers bound the park to the west and north, and part of its southern boundary is formed by the Fort Portal-Bundibugyo road (BirdLife International 2021). The park is almost entirely covered by forest, which is dominated by the tree species Cynometra alexandrii. As the site is cut off from the rest of East Africa by the Rwenzori massif, the forest is an easterly extension of the Ituri forest in northeastern DRC, and its flora and fauna show similarities with the forest in the Congo Basin (Sever 2021). The park was gazetted as Semliki Forest Reserve in 1932 and as National Park in 1993. The site is very rich in bird diversity and has been an Important Bird Area since 2001 (BirdLife International 2021). The park fauna is very rich and includes eight species of primates, 51 species of forest swallowtail and Charaxes butterflies (BirdLife International 2021).

Table 1. Basic site information for Semuliki National Park

Species	Pan troglodytes schweinfurthii
Area	220 km²
Coordinates	Lat: 0.828178 , Lon: 30.034272
Type of site	Protected area (National Park)
Habitat types	Subtropical/tropical moist lowland forest
Type of governance

Types of sites Governance types Habitat types

Ape status

Table 2. Ape population estimates reported for Semuliki 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 schweinfurthii	2001			0.21	50.15 (43-57)	Semuliki National Park	Line transects		Plumptre, Cox & Mugume 2003	Standing crop nest counts. Abundance is the number of nest building chimps.

Sampling methods Analytical frameworks

Threats

Main threats to chimpanzees include agricultural encroachment, poaching, and illegal harvest of forest products. The growing human population density in the county where the park is located (Bwamba) poses a big problem, as it is linked to a growing demand for agricultural land (BirdLife International 2021). In the 1970s and early 1980s approximately 30% of the original forest cover was cleared for agriculture and settlement (BirdLife International 2020). The encroachers were evicted in 1988 and 1990, allowing the forest to slowly regenerate (BirdLife International 2021).

Table 3. Threats to apes reported for Semuliki National Park

Category	Specific threats	Threat level	Description	Year of threat
2 Agriculture & aquaculture	2.1 Annual & perennial non-timber crops	Present (unknown severity)	Encroachment due to demand for agricultural land (BirdLife International 2021, Plumptre, Cox & Mugume 2003).	2003-Ongoing (2021)
4 Transportation & service corridors	4.1 Roads & railroads	Present (unknown severity)	Roads (Plumptre, Cox & Mugume 2003).	Ongoing (2003)
5 Biological resource use	5.1 Hunting & collecting terrestrial animals	Present (unknown severity)	Illegal harvest of forest products, including medicinal plants, bush ropes, poles, and rattan (BirdLife International 2021, Plumptre, Cox & Mugume 2003).	Ongoing (2003)
5 Biological resource use	5.1 Hunting & collecting terrestrial animals	Present (unknown severity)	Hunting traps (BirdLife International 2021, Plumptre, Cox & Mugume 2003).	Ongoing (2003)

Threats

Conservation activities

Table 4. Conservation activities reported for Semuliki National Park

Category	Specific activity	Description	Implementing organization(s)	Year of activity
5 Protection & restoration	5.2 Legally protect ape habitat	The site is designated as a national park.		1990-Ongoing (2026)
8 Permanent presence	8.2 Run tourist projects and ensure permanent human presence at site	Chimpanzee trekking and other activities are offered at the site since early 2000s (AfricaSky).		2000-Ongoing (2021)

Conservation activities

Challenges

Table 5. Challenges reported for Semuliki National Park

Challenges	Specific challenges	Source	Year(s)
	Not reported

Challenges

Enablers

Table 6. Enablers reported for Semuliki 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

A study that produced a historical base-line model of chimpanzee metapopulation dynamics in eastern DRC and northwestern Uganda found that chimpanzees in Semuliki National Park are genetically closer to the populations in Toro-Semliki Wildlife Reserve and Itwara Forest Reserve than to the population in Rwenzori National Park (Rich et al. 2020).

Documented behaviours

Table 7. Behaviours documented for Semuliki 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. (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 Semuliki 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]	22	23.1	23.2	23.4	24.5
Annual precipitation [mm]	1345	1387	1479	1300	1575
Max no. consecutive dry days (per year)	12.3	19.7	23.6	22.5	21.3
No. days with heavy precipitation (per year)	6.8	10.1	9.7	10.5	16

Table 9. Projected exposure of apes to extreme climate impact events in Semuliki 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	2.5	0.04	0	0	2.5	0.34	1.5	0.02
Drought	0	0	0	0	0	0	0	0
Heatwave	0	0	0	0	0	0	0	0
River flood	1.75	0.05	4	1.37	1	0.01	5.75	0.95
Tropical cyclone	0	0	0	0	0	0	0	0
Wildfire	30	1.03	30	1.01	29	0.98	29	0.79

Precipitation anomaly in Semuliki National Park
Temperature anomaly in Semuliki National Park

External links

References

BirdLife International. (2021). Important Bird Areas factsheet: Semliki National Park. Retrieved October 25, 2021, from http://www.birdlife.org

Plumptre, A. J., Cox, D., & Mugume, S. (2003). The status of chimpanzees in Uganda. Albertine Rift Technical Report Series No. 2. Wildlife Conservation Society. link

Rich, A. M., Wasserman, M. D., Hunt, K. D., & Kaestle, F. A. (2020). Chimpanzee (Pan troglodytes schweinfurthii) Population Spans Multiple Protected Areas in the Albertine Rift. Folia Primatologica, 91(6), 595-609. doi:10.1159/000508073

Sever, Z. (2021). Searching for the okapi (Okapia johnstoni) in Semuliki National Park, Uganda. African Journal of Ecology, 59(1), 286–292. doi:10.1111/aje.12796

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

AfricaSky. https://www.africaskysafari.com/semuliki-national-park

Page created by: APES Atlas Team Date: 2021-10-29