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Providing evidence to improve practice

Action: Run tourist projects and ensure permanent human presence at site Primate Conservation

Key messages

  • Three studies, including two before-and-after studies and one controlled study in Rwanda, Uganda and the Republic of Congo found that numbers of mountain gorillas increased after touristic projects were initiated, alongside other interventions. One before-and-after and site comparison study in Rwanda found that the number of immature mountain gorillas increased by 22% and the number of snares declined by 30% after a tourism project was initiated, alongside other interventions.
  • One before-and-after study in Kenya found that numbers of Tana River red colobus and crested mangabeys decreased despite implementing a tourism project, alongside other interventions.
  • One before-and-after study in Belize found that numbers of black howler monkeys increased by 138% over 13 years after a tourism project was implemented, alongside other interventions.
  • One before-and-after, replicated study in China found that implementing an intensive tourism project for Tibetan macaques that included food provisioning and range restrictions, increased their stress levels compared to previous periods, with infant mortality reaching 100% in some years.
  • One before-and-after study in Madagascar found that after implementing a tourism project the population size and/or body size and group size declined for two lemur species but the number of individuals increased for one other lemur species. 

Supporting evidence from individual studies

1 

A before-and-after trial in 1984-1987 in tropical montane forests in the Virunga ecosystem in Rwanda and the Democratic Republic of Congo found that mountain gorilla Gorilla beringei beringei populations involved in a tourism viewing project initiated in 1985 along with other interventions, increased from 242 to 279 individuals (15% increase) from 1981-1986. In addition, average group size increased by 17% (8.5 to 9.2 individuals) and the immature proportion increased by 8% (39.7 to 48.1) over the same time period. Regular total counts of this population were conducted since 1973 by research staff. Anti-poaching guards regularly patrolled the area and removed snares. Guards were  provided with better equipment, which allowed them to increase patrol frequency and effectiveness. An additional multi-organisation conservation project started in 1979. The study does not distinguish between the effects of the different interventions mentioned above.

2 

A controlled study in 1984-1987 in tropical montane forest in Virunga National Park in the Democratic Republic of Congo found that the resident mountain gorilla Gorilla beringei beringei population that was regularly visited by tourists had increased over three years. The percentage of immature gorillas in the groups regularly monitored by the tourism project was 50.8%, compared to 40.8% in groups that were not monitored. However, no statistical tests were carried out to determine whether this difference was significant. Furthermore, average group size in the monitored vs unmonitored population was 10.4 and 7.1 gorillas, respectively. Within a period of ten months, tourist receipts rose from zero to about US$1800/ month. Three gorilla groups living at the edge of the park were habituated to human presence and one of them received once-a-day visits from a maximum of six people since September 1985.

3 

A before-and-after trial in 1975-1985 in swamp and riverine forest in Tana River Primate Reserve, Kenya found that despite the establishment of a tourism enterprise in the reserve along with other interventions, Tana River red colobus Colobus badius rufomitratus and crested mangabeys Cercocebus galeritus galeritus decreased over a ten year period. Overall population size decreased from 1,200-1,800 to 200-300 individuals (83% decrease for colobus and from 1,100-1,500 to 800-1,100 (25% decrease) individuals for mangabeys. The number of forest patches inhabited by these two species also decreased over the same time period. No statistical tests were carried out to determine whether this decrease was significant. Results of total counts in 1985 and in 1973-1975 were compared to estimate population change. A permanent tourist lodge was built in 1977 and was operated until 1981, offering game drives, boat trips and guided walks. In 1976, the area became a National Reserve including a permanent ranger post to house reserve staff. The study does not distinguish between the effects of the different interventions mentioned above.

4 

A before-and-after trial in 1985-1998 in riparian forest at Community Baboon Sanctuary, Belize found that when a tourism program was implemented along with ten other interventions, the sanctuary’s black howler monkey Alouatta pigra population increased by 138% over 13 years. The population increased from 840 to over 2,000 individuals, although no statistical tests were carried out to determine whether this increase was significant. Additional interventions included the protection of the sanctuary by the local communities, preserving forest buffer strips along property boundaries and a forest corridor along the river, constructing pole bridges over man-made gaps, involving local communities in the management of the sanctuary, preserving important howler food trees in large clearings, a research program, presence of permanent staff, creation of a museum for education purposes, and monetary benefits (income from tourism and craft industries) to local communities for sustainably managing their forest and its wildlife communities. The study does not distinguish between the effects of the different interventions mentioned above.

5 

A before-and-after trial and site comparison in 1976-1988 in tropical forest of the Volcanoes National Park, Rwanda found that the number of immature mountain gorillas Gorilla beringei beringei on the Rwandan side of the park increased and snares decreased after the initiation of a tourist program, along with other interventions. In 1981, sampled quadrats on the Rwandan side of the park contained 30% snares compared to 70% on the Ugandan and DRC side of the park. Immature individual numbers increased by 22% in Rwanda, but declined by 30% in the other two countries. No statistical tests were carried out to determine whether these differences were significant. In 1979, the Mountain Gorilla Project implemented a managed tourism program. Using the income generated by this program, the training, equipping and management of anti-poaching patrols was made possible. A conservation education program was also implemented, but no further details of this program were reported in the study. In 1976, all cattle were removed from the park in Rwanda. The study does not distinguish between the effects of the different interventions mentioned above.

6 

A controlled, before-and-after study in 1967-2008 in tropical montane forest in Volcanoes-, Mgahinga-, and Virunga National Parks in Rwanda, Uganda, and the Democratic Republic of Congo, respectively found that a mountain gorilla Gorilla beringei beringei population that was part of an ecotourism program along with ten other interventions, increased in size over time. Annual population growth was 4.1%, resulting in an overall population increase of 168% over 41 years. No statistical tests were carried out to determine whether this increase was significant. As part of this program, gorillas were habituated to human presence. A long-term research program started in 1967. Visitors/researchers had to follow strict health procedures, included keeping a safety distance to the gorillas, wearing face-masks, spending only a limited amount of time with gorilla groups, ensuring that visitors/researchers were healthy, and disinfecting visitor’s/researcher’s clothes, boots etc. Gorillas were continuously monitored by vets and treated if necessary. When gorillas in the treatment population died, their cause of death was investigated. The study only tests for the effect of veterinary interventions, but does not distinguish between the effects of the other interventions mentioned above.

7 

One before-and-after study in 1986-2007 in montane evergreen forest in Huangshan, China found that implementing a tourism project for Tibetan macaques Macaca thibetana that included intensive management and food provisioning, increased their stress levels compared to previous periods, with adult mortality and productivity unaffected but greatly increased infant mortality, reaching 100% in some years. Productivity was unaffected (adult females giving birth before tourism: 71%; after tourism management: 73%) but infant mortality increased from 14.8% in 1986-1991 to 54.6% after tourism management was implemented. Infant mortality peaked at 90-100% during intense tourism management but dropped to 16.7% after management suspension in 2003. Infants were killed through wounding by adult macaques, with rates increasing from 0% before tourism to 60% after tourism. Tourism management started in 1992 but intensified in 1994 and 2002 with range restrictions to increase macaque visibility for tourists. Long-term records from multiple researchers were used for data on group membership, births, and deaths from 1986-2007. Two monkey troups were studied and behaviour of macaques and visitors was recorded. Tourists watched macaques from wooden pavilions and feeding or touching them was prohibited but enforcement was lacking and breached even by staff. Introducing tourism was not directly aimed at primate conservation but was intended as a more conservation-oriented project compared to unregulated primate tourism targeting the same species at Mount Emei, China. 

8 

One before-and-after and review study in 1986-2010 in montane rainforest in Ranomafana National Park, Madagascar found that after implementing a lemur tourism project alongside other interventions, the population size of Milne-Edwards’ sifaka Propithecus edwardsi and greater bamboo lemur Prolemur simus declined severely while the golden bamboo lemur Hapalemur aureus had increased in population size. In 1996-2008 population size and group size of Milne-Edwards’ sifaka declined, with almost 50% decline in population size in 2005-2009 (data as graphs) and a 7% reduction in body size over 21 years (5.7kg in 1987; 5.3kg in 2008). High tourist numbers in one site resulted in changed activity patterns for Milne-Edwards’ sifaka, with less time spent foraging and grooming (data as graphs). Population size and group size of greater bamboo lemur also declined following the implementation of a tourism project while golden bamboo numbers increased (data not included). In 1993-2011 the number of tourists in Ranomafana increased from around 4000/year to almost 24000/year (data as graphs). Lemur behaviour and population counts were collected in several studies.

Referenced papers

Please cite as:

Junker, J., Kühl, H.S., Orth, L., Smith, R.K., Petrovan, S.O. & Sutherland, W.J. (2018) Primate conservation. Pages 393-445 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2018. Open Book Publishers, Cambridge, UK.