Summary

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Eastern chimpanzees (Pan troglodytes schweinfurthii) are present in Loasi River Forest Reserve.
The population size is unknown.
The population trend is unknown.
The site has a total size of 334 km².
Key reported threats to chimpanzees are Agro-pastoralism, bushmeat hunting, and logging.
The main conservation activities reported are involving the local community in ape research, education and outreach.
The site is a forest reserve.

Site characteristics

Table 1. Basic site information for Loasi River Forest Reserve

Species	Pan troglodytes schweinfurthii"
Area	334 km²
Coordinates	Lat: -8.181454 , Lon: 31.123284
Type of site	Protected area (Forest Reserve)
Habitat types	Subtropical/tropical dry forest, Other
Type of governance	Governance by government

Types of sites Governance types Habitat types

Ape status

Table 2. Ape population estimates reported for Loasi River Forest Reserve

Species	Year	Occurrence	Density estimate [ind./ km²] (95% CI)	Survey area	Sampling method	Analytical framework	Source	Comments
Pan troglodytes schweinfurthii	1997	Present					Ogawa et al. 1997
Pan troglodytes schweinfurthii	2005-2009	Present	0.21	Southern Lake Tanganyika	Line transects & recces	Distance sampling	Davenport et al. 2010	60-85 chimpanzees estimated across all sites south of Kipili to Kalambo NFR
Pan troglodytes schweinfurthii	2022	Present			Reconnaissance walk	Spatial mapping	WCS Tanzania, 2022	57 nests of all ages counted in 5 days (Nicholas A pers.comm. 2026).
Pan troglodytes schweinfurthii	2023	Present			Reconnaissance walk	Spatial mapping	WCS Tanzania, 2023	45 nests of all ages counted in 5 days (Nicholas A pers.comm. 2026).
Pan troglodytes schweinfurthii	2024	Present			Reconnaissance walk	Spatial mapping	WCS Tanzania, 2024	32 nests of all ages counted in 3 days (Nicholas A pers.comm. 2026).

Sampling methods Analytical frameworks

Threats

Table 3. Threats to apes reported for Loasi River Forest Reserve

Category	Specific threats	Threat level	Description	Year of threat
2 Agriculture & aquaculture	2.3 Livestock farming & ranching	Low (up to 30% of population affected)	Agro-pastoralist incursion into the forest reserve, semi-permanent bomas for livestock established, use of water points and fire - general habitat degradation associated with this (Nicholas A pers.comm. 2026).	2005-Ongoing (2026)
5 Biological resource use	5.1.1 Subsistence bushmeat hunting	Medium (30-70% of population affected)	Villages growing in size adjacent to the reserve, regular evidence of hunting using dogs, guns and drop traps detected (Nicholas A pers.comm. 2026).	2005-Ongoing (2026)
5 Biological resource use	5.3 Logging & wood harvesting	Low (up to 30% of population affected)	Selective logging of mainly hardwood species (Nicholas A pers.comm. 2026).	2005-Ongoing (2026)

Threats

Conservation activities

Table 4. Conservation activities reported for Loasi River Forest Reserve

Category	Specific activity	Description	Implementing organization(s)	Year of activity
4 Education & awareness	4.1 Educate local communities about apes and sustainable use	Outreach with local primary and secondary schools (Nicholas A pers.comm. 2026).	Wildlife Conservation Society (WCS)	2022
4 Education & awareness	4.2 Involve local community in ape research and conservation management	Recruit local field assistance and trackers for monitoring work (Nicholas A pers.comm. 2026).	Wildlife Conservation Society (WCS)	2022-Ongoing (2026)
7 Economic & other incentives	7.2 Provide non-monetary benefits to local communities for sustainably managing their forest and its wildlife (e.g., better education, infrastructure development)	Support village land use planning to put aside areas of natural habitat adjacent to Loasi - community forest establishment (Nicholas A pers.comm. 2026).	Wildlife Conservation Society (WCS)	2023
5 Protection & restoration	5.2 Legally protect ape habitat	The site is a Forest Reserve since 1957. WCS promotes the upgrading of Loasi to Nature Forest Reserve status and merge with adjacent Kalambo NFR (Nicholas A pers.comm. 2026).	Wildlife Conservation Society (WCS)	1957-Ongoing (2026)

Conservation activities

Challenges

Table 5. Challenges reported for Loasi River Forest Reserve

Challenges	Specific challenges	Source	Year(s)
2 Resources and capacity	2.2 Lack of staff	Nicholas A pers.comm. 2026	1957-Ongoing (2026)
2 Resources and capacity	2.4 Lack of continuous/long-term funding	Nicholas A pers.comm. 2026	Ongoing (2026)
2 Resources and capacity	2.7 Lack of infrastructure	Nicholas A pers.comm. 2026	1957-Ongoing (2026)
4 Institutional support	4.2 Lack of government support	Nicholas A pers.comm. 2026	1957-Ongoing (2026)

Challenges

Enablers

Table 6. Enablers reported for Loasi River Forest Reserve

Enablers	Specific enablers	Source	Year(s)

Enablers

Research activities

Documented behaviours

Exposure to climate change impacts

External links

References

Davenport, TRB, Mpunga NE, Picton Phillipps, G, Machaga, SJ, De Luca, DW, Kibure O & Abeid, Y. 2010. The conservation status of the chimpanzee in Southern Tanganyika 2005-2009. Unpublished Report. Wildlife Conservation Society.
Lucchesi, S., Cheng, L., Janmaat, K., Mundry, R., Pisor, A., & Surbeck, M. (2020). Beyond the group: how food, mates, and group size influence intergroup encounters in wild bonobos. Behavioral Ecology, 31(2), 519-532.
Ogawa, H; Kanamori, M & Mukeni, SH. 1997. The discovery of chimpanzee in the Lwazi River area, Tanzania: a new southern distribution limit. Pan Africa News 4(1); 3
WCS Tanzania 2022. Unpublished field survey report
WCS Tanzania 2023. Unpublished field survey report
WCS Tanzania 2024. Unpublished field survey report

Page created by: Aaron Nicholas Date: 2026-04-28