Limit time that researchers/tourists are allowed to spend with habituated animals

How is the evidence assessed?
  • Effectiveness
  • Certainty
  • Harms

Study locations

Key messages

  • One controlled study in Indonesia found that reintroduced Sumatran orangutans that spent limited time with caretakers acted more similar to wild orangutans than orangutans that spend more time with caretakers, alongside other interventions.
  • One before-and-after study in Rwanda, Uganda and the Democratic Republic of Congo found that numbers of mountain gorillas increased by 168% over 41 years while being visited by researchers and visitors during a restricted amount of time, alongside other interventions.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A controlled study in 2004-2005 in a mosaic of logged and secondary tropical forest in Bukit Tigapuluh National Park, Indonesia found that reintroduced Sumatran orangutans Pongo abelii that spent only a limited amount of time with their caretakers along with other interventions, acted more like wild orangutans after release compared to individuals that had regular and close contact to caretakers. The behaviour of the three non-habituated orangutans with minimal human contact resembled that of wild orangutans more than that of the five habituated individuals in the way that they built nests, their food choice and canopy use. Furthermore, the former spent more time interacting socially with previously released orangutans. Non-habituated orangutans were released after they spent 6-month at a sanctuary to acclimatize. Human-habituated individuals were kept in semi-free conditions for 7-9 months prior to release where staff members guided them to the forest on a daily basis and tried to foster natural behaviour. The study does not distinguish between the effects of the different interventions mentioned above.

    Study and other actions tested
  2. 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 found that the mountain gorilla Gorilla beringei beringei population that was regularly visited by tourists and researchers that were restricted in the amount of time they were allowed to spend with them alongside ten other interventions, increased 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. One-hour visits were made to each gorilla group daily by tourists. Researchers typically spent no more than four hours with the research-habituated groups. As part of the ecotourism- and research programmes, gorillas were habituated to human presence, where visitors/researchers had to follow strict health procedures; these included keeping a safety distance to the gorillas, wearing face-masks, ensuring that visitors/researchers were healthy, disinfecting visitor’s/researcher’s clothes, boots etc. Gorillas were continuously monitored by vets and received medical treatment if necessary. When gorillas died, their cause of death was clinically determined. The study does not distinguish between the effects of the different interventions mentioned above.

    Study and other actions tested
Please cite as:

Junker, J., Kühl, H.S., Orth, L., Smith, R.K., Petrovan, S.O. & Sutherland, W.J. (2020) Primate Conservation. Pages 431-482 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

Primate Conservation

This Action forms part of the Action Synopsis:

Primate Conservation
Primate Conservation

Primate Conservation - Published 2017

Primate Synopsis

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What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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