Ugalla

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Summary

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• 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

Species	Pan troglodytes schweinfurthii
Area	3,352 km²
Coordinates	Lat: -5.811084 , Lon: 31.901811
Type of site	Non-protected area
Habitat types	Subtropical/tropical dry forest, Grassland, Savanna, Grassland
Type of governance

Types of sites Governance types Habitat types

Ape status

Table 2. Ape population estimates reported for Ugalla

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	1995-2005			0.07-0.09	200-300	Ugalla (3,352 km²​)	Line transects & recces		Ogawa et al. 2007
Pan troglodytes schweinfurthii	2009-2010			0.25 (0.16-0.38)	322 (227-373)	Ugalla region (624 km²​)	Reconnaissance walk		Moore & Vigilant 2014	Standard and spatially explicit genetic capture-recapture methods

Sampling methods Analytical frameworks

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 reported for Ugalla

Category	Specific threats	Threat level	Description	Year of threat
7 Natural system modifications	7.1 Fire & fire suppression	Present (unknown severity)	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)
5 Biological resource use	5.1 Hunting & collecting terrestrial animals	High (more than 70% of population affected)	Poaching is a serious problem in Ugalla because of poverty and a massive increase in demand for animal protein (Masanja 2014).	Ongoing (2014)

Threats

Challenges

Table 5. Challenges reported for Ugalla

Challenges	Specific challenges	Source	Year(s)
	Not reported

Challenges

Enablers

Table 6. Enablers reported for Ugalla

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 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 7. Behaviours documented for Ugalla

Category	Behavior	Observation type	Prevalence	Observation dates	Source	Habituation	Species	Comment
	Using tools to dig for plant underground storage organs				Hernandez-Aguilar, Moore & Pickering 2007

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 Ugalla

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]	21.2	22.3	22.3	22.3	23.8
Annual precipitation [mm]	1106	1089	1131	1076	1123
Max no. consecutive dry days (per year)	128.9	128.3	124.3	130	126.9
No. days with heavy precipitation (per year)	4.2	2.5	3.8	2.4	4.6

Table 9. Projected exposure of apes to extreme climate impact events in Ugalla

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	0.5	0.05	0	0	1	0.1	0.5	0
Drought	0	0	0	0	0	0	0	0
Heatwave	0	0	0	0	0	0	0	0
River flood	1	0.1	2	0.36	1.75	0.09	4	0.41
Tropical cyclone	0	0	0	0	0	0	0	0
Wildfire	30	2.55	30	2.41	29	2.69	29	2.65

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 created by: APES Atlas Team Date: 2021-11-14