Summary

Eastern chimpanzees (Pan troglodytes schweinfurthii) are present in Ugalla.
It has been estimated that 322 (CI: 227–373) individuals occur in the site.
The chimpanzees population trend is unknown.
The site has a total size of 3,352 km².
Key threats to chimpanzees are poaching and habitat encroachment.
Conservation activities are not documented.

Site characteristics

The Ugalla region is located approximately 65 km east of Lake Tanganyika, in western Tanzania (Moore & Vigilant 2014). A large part of the region is found within the East Tongwe Forest Reserve and is not part of the national park system of Tanzania (Moore & Vigilant 2014). The site covers approximately 3,350 sq.km and is one of the most seasonal, dry, and open chimpanzee habitats (Moore & Vigilant 2014). The region is classified as savanna-woodland; the grassy groundcover is extensive, the drought season takes place between May and October, and there is minimal rainfall. Small strips of forest occur around the ephemeral rivers of Ugalla (Moore & Vigilant 2014).

Table 1. Basic site information for Ugalla

Area	3,352 km²
Coordinates
Designation	Unclassified
Habitat types	Subtropical/tropical dry forest, subtropical/tropical dry grassland, savanna, subtropical/tropical seasonally wet/flooded grassland

IUCN habitat categories Site designations

Ape status

Table 2. Ape population estimates in Ugalla

Species	Year	Abundance estimate (95% CI)	Density estimate [ind./ km²] (95% CI)	Encounter rate (nests/km)	Area	Method	Source	Comments	A.P.E.S. database ID
Pan troglodytes schweinfurthii	1995-2005	200-300	0.07-0.09		Ugalla region 3,352 sq. km	Index survey (reconnaissance walk) & Line transect survey	Ogawa et al. 2007
Pan troglodytes schweinfurthii	2009-2010	322 (227–373)	0.25 (0.16–0.38)		Ugalla region, 624 sq.km	Capture-recapture method	Moore & Vigilant 2014	Standard and spatially explicit genetic capture–recapture methods

Threats

The area has been under increasing pressure from human disturbance. The greatest threats include agricultural expansion, cattle herding, fire, logging, and poaching (Masanja 2014). Hunting with snares is very common, but large game such as buffalo (Syncerus caffer), rhinoceros (Diceros bicornis) or elephant (Loxodonta africana) are hunted with firearms. Elephant, rhinoceros and lion numbers have declined sharply in Ugalla, along with increased illegal ivory trade (Masanja 2014).

Table 3. Threats to apes in Ugalla

Category	Specific threats	Threat level	Description	Year of threat
1. Residential & commercial development		Unknown
2. Agriculture & aquaculture		Unknown
3. Energy production & mining		Unknown
4. Transportation & service corridors		Unknown
5. Biological resource use	5.1 Hunting & collecting terrestrial animals	High	Poaching is a serious problem in Ugalla because of poverty and a massive increase in demand for animal protein (Masanja 2014).	Ongoing (2014)
6. Human intrusion & disturbance		Unknown
7. Natural system modifications	7.1 Fire & fire suppression	Present, but threat severity unknown	People burn grassland during the dry season. Although the fires have direct and indirect influences on vegetation and wild animals, trees don't die from the fires; the woodland in the area is considered fire-adapted (Ogawa 2007).	Ongoing (2007)
8. Invasive & other problematic species, genes, diseases		Unknown
9. Pollution		Unknown
10. Geological Events		Absent
11. Climate change & severe weather		Unknown
12. Other options		Absent

IUCN Threats list

Conservation activities

Table 4. Conservation activities in Ugalla

Category	Specific activity	Description	Year of activity
1. Residential & commercial development	Not reported
2. Agriculture & aquaculture	Not reported
3. Energy production & mining	Not reported
4. Transportation & service corridors	Not reported
5. Biological resource use	Not reported
6. Human intrusion & disturbance	Not reported
7. Natural system modifications	Not reported
8. Invasive & other problematic species, genes, diseases	Not reported
9. Pollution	Not reported
10. Education & Awareness	Not reported
11. Habitat Protection	Not reported
12. Species Management	Not reported
13. Livelihood; Economic & Other Incentives	Not reported

Conservation activities list (Junker et al. 2017)

Challenges

Table 5. Challenges reported for Ugalla

Challenge	Source
Not reported

Research activities

A behavioral study of chimpanzees at the site documented the use of tools to dig for plant underground storage organs (USOs), suggesting that exploitation of such resources was within the cognitive and technological reach of the earliest hominins (Hernandez-Aguilar, Moore & Pickering 2007).

Documented behaviours

Table 6. Ape behaviors reported for Ugalla

Behavior	Source
Using tools to dig for plant underground storage organs	Hernandez-Aguilar, Moore & Pickering 2007

External links

Relevant datasets

A.P.E.S Portal

References

Moore, D. L., & Vigilant, L. (2014). A population estimate of chimpanzees (Pan troglodytes schweinfurthii) in the Ugalla region using standard and spatially explicit genetic capture–recapture methods. American Journal of Primatology, 76(4), 335-346.
Ogawa, H., Moore, J., Pintea, L., & Hernandez-Aguilar, A. (2007). Sleeping parties and nest distribution of chimpanzees in the savanna woodland, Ugalla, Tanzania. International Journal of Primatology, 28(6), 1397-1412.
Hernandez-Aguilar, R. A., Moore, J., & Pickering, T. R. (2007). Savanna chimpanzees use tools to harvest the underground storage organs of plants. Proceedings of the National Academy of Sciences, 104(49), 19210-19213.
Masanja, G. F. (2014). Human population growth and wildlife extinction in Ugalla ecosystem, western Tanzania. Journal of Sustainable Development Studies, 5(2).

Page completed by: A.P.E.S. Wiki team Date: 14/11/2021

Ugalla

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