Action: Create/protect forest patches in highly fragmented landscapes
Key messagesRead our guidance on Key messages before continuing
- One before-and-after study in Belize found that black howler monkey numbers increased by 138% over 13 years after the protection of forest along property boundaries and across cleared areas, alongside other interventions.
Habitat destruction and fragmentation are important factors in the decline of primate populations. Small patches of habitat support smaller populations and if individuals are unable to move to other suitable areas of habitat, populations become isolated, which in turn can make them more vulnerable to extinction. Creating/protecting patches of suitable primate habitat (e.g. forest patches) in highly fragmented landscapes may enable them to move between these different areas and help maintain primate populations. Some primate species, such as chimpanzees Pan troglodytes (e.g. McLennan 2008), orangutans Pongo spp. (e.g. Spehar & Rayadin 2017), or samango monkeys Cercopithecus albogularis labiatus (e.g. Nowak et al. 2017) show very high behavioural flexibility enabling them to survive in human-modified landscapes. However, it remains to be seen whether such populations will also survive in the long-term.
McLennan M.R. (2008) Beleaguered chimpanzees in the agricultural district of Hoima, Western Uganda. Primate Conservation, 23, 45–54.
Spehar S.N. & Rayadin Y. (2017) Habitat use of Bornean orangutans (Pongo pygmaeus morio) in an industrial forestry plantation in East Kalimantan, Indonesia. International Journal of Primatology, 38, 358–384.
Nowak K., Wimberger K., Richards S.A., Hill R.A. & le Roux A. (2017) Samango monkeys (Cercopithecus albogularis labiatus) manage risk in a highly seasonal, human-modified landscape in Amathole Mountains, South Africa. International Journal of Primatology, 38, 194–206.
Supporting evidence from individual studies
A before-and-after trial in 1985-1998 in secondary riparian forest in the Community Baboon Sanctuary, Belize, South America found that a population of black howler monkey Alouatta pigra, for which forest buffer strips along property boundaries and strips of forest across large cleared areas were maintained alongside ten other interventions, increased by 138% over 13 years. The population increased from 840 to more than 2,000 individuals (138%), although no statistical tests were carried out to determine whether this difference was significant. Additional interventions included the protection of the sanctuary by the communities surrounding it, preserving a forest corridor along the river, constructing pole bridges over man-made gaps, preserving important howler food trees in large clearings, involving local communities in the management of the sanctuary, creation of a museum for education purposes, an eco-tourism and research program, presence of permanent staff, and monetary (income from tourism and craft industries) benefits 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.