Dimonika Biosphere Reserve

Central Africa > Republic of the Congo > Dimonika Biosphere Reserve

Summary

• Central chimpanzees (Pan troglodytes troglodytes) and western lowland gorillas (Gorilla gorilla gorilla) are present in Dimonika Biosphere Reserve.
• The gorilla population at the site has been estimated at 113 nest building individuals.
• The great ape population trend is unknown.
• The site has a total size of 1,360 km².
• Key threats to great apes are hunting and gold mining.
• Conservation activities at the site are not reported.
• The site was declared a UNESCO Biosphere Reserve in 1988.

Site characteristics

The site is located in the central Mayombe mountain chain in the Republic of Congo, about 50 km from the Atlantic coast. It was declared a UNESCO Biosphere Reserve in 1988 (UNESCO). The reserve has a remarkable mountainous terrain dominated by lowland guineo-congolese rainforest and savanna patches. A total of 275 bird species have been recorded at Dimonika, including rare species, such as Bubo shelleyi. In addition to western lowland gorillas and chimpanzees, other species of conservation concern found at the site include forest elephants (Loxodonta cyclotis), African forest buffalo (Syncerus caffer nanus), and mandrills (Mandrillus sphinx) (BirdLife International 2021). The southern edge of the reserve coincides with a road and part of a railway line that connect Brazzaville to Pointe-Noire, along which lie several large settlements. There is also a road that goes into the reserve to the villages of Dimonika and Makaba (BirdLife International 2021).

Table 1. Basic site information for Dimonika Biosphere Reserve

Area	1,360 km²
Coordinates	-4.167361 S, 12.346388 E
Designation	Biosphere Reserve
Habitat types	Subtropical/tropical moist montane forest, savanna

IUCN habitat categories Site designations

Ape status

With support from the U. S. Fish & Wildlife Service's Great Ape Conservation Fund, in 2009 the Jane Goodall Institute (JGI), in partnership with the Ministère de l'Economie Fo­restière et de l'Environnement, was able to conduct biodiversity and socio-economic surveys in Dimonika Biosphere Reserve (Pintea, Atencia & Cox 2013). A JGI survey team conducted a series of initial reconnaissance walks within the reserve. A sampling plan was then designed using Distance software that identified 57 one-kilometer line transects. The field teams were able to collect data along 50 line transects with a total length of 44,590 km. Some inaccessible places on very steep slopes still remain quite intact with mature forest (Pintea, Atencia & Cox 2013). The survey confirmed the presence of a population of western lowland gorilla (Gorilla gorilla gorilla), estimated at 113 nest building individuals. Some ape nests could not be identified to the species level and the number of those individuals (chimpanzees or gorillas) were estimated at 163. Furthermore, gorillas were among large mammal species – including chimpanzees, duikers and bush pigs – whose traces (footprints, droppings, tracks, crossings) were the most frequently encountered (Pintea, Atencia & Cox 2013).

Table 2. Ape population estimates in Dimonika Biosphere Reserve

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
Gorilla gorilla gorilla	2009	113			Dimonika Biosphere Reserve	Line transects (Distance)	Pintea, Atencia & Cox 2013	113 nest building individals

Threats

Hunting and mining are the primary threats to great apes at the site (Pintea, Atencia & Cox 2013; BirdLife International 2021). During the 2009 wildlife inventory, hunting signs (animals slaughtered, cartridge cases, hunting trails, signs of passage) and mining signs were frequently observed (Pintea, Atencia & Cox 2013). The main activity in the villages adjacent to the site is hunting, as the villages are located on major roads and constantly have customers. Old logging roads going into the reserve still serve as a network of hunting trails (Pintea, Atencia & Cox 2013). In the village of Dimonika, the hamlets of Voula and Ndéguélé (former secondary mining areas), Vigoureux, and the village of Poung, artisanal gold mining is increasing (Pintea, Atencia & Cox 2013).

Table 3. Threats to apes in Dimonika Biosphere Reserve

Category	Specific threats	Threat level	Quantified severity	Description	Year of threat
1. Residential & commercial development		Unknown
2. Agriculture & aquaculture	2.1 Annual & perennial non-timber crops	Present, but threat severity unknown		Commercial and subsistence farming (Pintea, Atencia & Cox 2013).	Ongoing (2013)
3. Energy production & mining	3.2 Mining & quarrying	High		Commercialized artisanal gold mining (Pintea, Atencia & Cox 2013).	Ongoing (2013)
4. Transportation & service corridors		Unknown
5. Biological resource use	5.1 Hunting & collecting terrestrial animals	High		Subsistence hunting as well as commercialized bushmeat trade. Hunting tracks starting from the village follow old, established logging tracks (Pintea, Atencia & Cox 2013).	Ongoing (2013)
	5.3 Logging & wood harvesting	Low		Old logging sites and tracks were often found during wildlife inventory (Pintea, Atencia & Cox 2013).	Ongoing (2013)
6. Human intrusion & disturbance		Unknown
7. Natural system modifications		Unknown
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 Dimonika Biosphere Reserve

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	11.2. Legally protect primate habitat	The site has been a Biosphere Reserve since 1988.	Ongoing (2021)
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 Dimonika Biosphere Reserve

Challenge	Source
Absence of management	Pintea, Atencia & Cox 2013

Research activities

Documented behaviours

Table 6. Ape behaviors reported for Dimonika Biosphere Reserve

Behavior	Source
Not reported

External links

Relevant datasets

A.P.E.S Portal

References

BirdLife International. (2021). Important Bird Areas factsheet: Dimonika Biosphere Reserve. Downloaded from http://www.birdlife.org on 14/10/2021.
Pintea, L., Atencia, R., & Cox, D. (2013). Gorillas in the Dimonika Biosphere Reserve. Gorilla Journal 46, 16-19. Online: https://www.berggorilla.org/en/gorillas/species/western-gorillas/articles-western-gorillas/gorillas-in-the-dimonika-biosphere-reserve/

Page completed by: A.P.E.S. Wiki team Date: 15/10/2021