Long-tailed macaques (Macaca fascicularis) are Least Concern on the IUCN Red List. 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. To reduce our knowledge gap on ecological consequences of human provisioning of long-tailed macaques, we conducted research on a synanthropic long-tailed macaque population in Baluran National Park, Indonesia. We investigated the distribution, abundance and density using line transect distance sampling and SDM habitat suitability. We compared the ranging patterns of a provisioned and a non-provisioned long-tailed macaque group through GPS-collaring, and subsequent AKDE home range 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. 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 41individuals/km2. 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 the two. 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. Most often humans initiated the human-macaque interactions, and both female and male macaques interacted more than expected. We encourage BNP management to focus more on human management than macaque management. We also encourage them to investigate intentions behind human behaviours towards the macaques before implementing management initiatives. 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.