Portrait of author

Malene Friis Hansen:
Ecology and conservation of long-tailed macaques in a human-macaque interface

Date: 28-11-2019    Supervisor: Torben Dabelsteen

Long-tailed macaques (Macaca fascicularis) are Least Concern on the IUCN Red List, and of no concern to most institutions across their range. In 2008 they were classified as “widespread, and rapidly declining” because of the lack of conservation and research attention, and the increase in trade for the biomedical industry, pet trade and culling in so-called conflict zones. Long-tailed macaques are CITES appendix II, and trade is regulated internationally. In Indonesia, they are not protected and national trade is not regulated. Information regarding their distribution, abundance, and ecology is lacking in all habitat countries, yet governments continue to implement management initiatives to reduce human-macaque conflicts without concern for the consequences for long-tailed macaque populations. Research into the behavioural consequences of human-macaque interactions on long-tailed macaque groups is plentiful and informative; however, research is sparse on the effects of human-macaque interactions, and especially provisioning on ranging patterns, population abundance and population distributions. To reduce our knowledge gap on ecological consequences of human provisioning of long-tailed macaques, and enable institutions and governments in longtailed macaque habitat countries, and here specifically in Baluran National Park (BNP), East Java, Indonesia, to create informed science-based management initiatives, we conducted research on a synanthropic long-tailed macaque population in BNP. We investigated the distribution, abundance and density through line transect distance sampling and Species Distribution Models habitat suitability. We compared the ranging patterns of a provisioned and a non-provisioned long-tailed macaque group through GPS-collaring, and subsequent Autocorrelated Kernel Density Estimates home range analysis and habitat selection analysis. Finally, we assessed human-macaque interactions through focal animal sampling and behavioural sampling observations in the provisioned group. We also investigated the Javan lutung (Trachypithecus auratus) population status and their poly-specific interactions with long-tailed macaques. My experiences with GPScollaring also led to participation in a GPS-collar review, and finally I collaborated in writing a statement regarding the conservation status of long-tailed macaques, advocating for future research and conservation measures.

Results from our population survey showed that long-tailed macaques were drawn to roads and trails, where provisioning occurred, and that the population density across the park was only 41 individuals/km2, which is lower than the average density for non-provisioned populations estimated by Fooden in 1995. Lutung distribution was slightly different as lutungs were present in more habitats than long-tailed macaques. We discovered a 25% co-occurrence of lutung and macaques throughout the park, and poly-specific associations between certain lutung and macaque groups. Our ranging analysis showed that the home range of the provisioned group of long-tailed macaques was 23 times smaller than that of the non-provisioned group. We also found that the home range of the provisioned group decreased even further with increasing number of visitors, an almost perfect negative correlation. Most often humans initiated the human-macaque interactions, and both females and male macaques interacted more than expected, while juveniles interacted less than expected.

Before commencing research, we assumed that BNP was experiencing an overpopulation of longtailed macaques, that they were detrimental to sympatric wildlife species, and that human-macaque conflicts with aggressive macaques took place. However, the results of our research did not support these assumptions, on the contrary they indicated quite the opposite encouraging BNP management to focus more on human management and not macaque management. We also encourage them to investigate intentions behind human behaviours towards the macaques before implementing management initiatives. Long-tailed macaques are a part of the ecosystems of BNP through their interaction with sympatric species and their seed dispersal abilities. They seemed not to be a part of human-macaque conflicts, but rather a part of a historic human-macaque interface. One that if understood and carefully managed may not be problematic. Therefore, we do not find it relevant to include translocating and or culling long-tailed macaques as part of BNP management initiatives, but instead encourage them to continue our research to investigate fluctuation over time in population density as well as human-macaque interactions. We encourage researchers and conservation practitioners working in long-tailed macaque habitat countries to consider our results and conduct similar research on long-tailed macaque populations including ethnography before implementing management measures. Long-tailed macaque may be in need of stronger conservation measures and we hope this thesis encourages the consideration of including long-tailed macaques in conservation planning.