Long‐Term Population Survey of the Sulawesi Black Macaques (Macaca nigra) at Tangkoko Nature Reserve, North Sulawesi, Indonesia

Abstract

The Sulawesi black macaque (Macaca nigra) population at Tangkoko Nature Reserve in North Sulawesi, Indonesia has been the focus of periodic study for over 30 years. The population has shown considerable decline during much of that time. Here we present the results of a long-term population survey of the Tangkoko M. nigra, conducted over the past decade, to provide updated information and on-going assessment of the population. Line-transect sampling was conducted annually from 1999 to 2002 and 2005 to 2011 along the same transect during a 2- to 3-week survey period. Although further decline in the population was observed at the outset of the survey, over the subsequent 12-year period we have seen stability in the population parameters with evidence of modest increases in both group and population density. During the 1999-2002 survey periods, there was a mean group density of 3.6 groups/km(2) and a mean population density of 39.8 individuals/km(2) . During 2005-2011, mean group density increased to 3.8 groups/km(2) and mean population density was 51.4 individuals/km(2) . The 2011 survey data indicated an estimated group density of 4.3 groups/km(2) and a population density of 61.5 individuals/km(2) . Given that our transect was located in the core of the Tangkoko reserve, our density estimates should be limited to that area of the reserve. One explanation for the apparent stabilization of the population may be tied to the increasing and sustained number of training and research programs being conducted at the reserve. This collective effort by local and international groups may be helping to reduce illegal activity in the reserve (i.e., hunting and habitat destruction) and generate greater awareness of this critically endangered species. Without the continued vigilance afforded by the existing research and training programs and the support and involvement of the local people, the M. nigra at the Tangkoko Nature Reserve will likely face further decline.

Identification of Entamoeba polecki with Unique 18S rRNA Gene Sequences from Celebes Crested Macaques and Pigs in Tangkoko Nature Reserve, North Sulawesi, Indonesia

“…The 2011 survey data in Tangkoko indicated an estimated group density of 4.3 groups/km 2 and a population density of 61.5 individuals/km 2 (Kyes et al. ). Therefore, we think that most of the samples collected were derived from different individuals.…”

The endemic seven: Four decades of research on the Sulawesi macaques

“…Population surveys conducted over the last four decades have documented an 80% decline in this taxon's population size due to high hunting pressure and continued habitat loss. [100][101][102][103][104][105] It is estimated that there are perhaps as few as 4,000-6,000 individuals left (Table 4). 54 There is, however, a sizeable introduced population of approximately 100,000 Crested black macaques on Bacan island, 300 kilometers east in the Maluku Islands.…”

Primate Infectious Disease Ecology: Insights and Future Directions at the Human-Macaque Interface

“…Yet some of these species, like toque macaques, remain listed as "vulnerable" or "endangered" on account of the negative effects of ecotourism and habitat loss throughout their range (IUCN 2019). Finally, some less ecologically flexible species like lion-tailed macaques (M. silenus), Tibetan macaques (M. thibetana), and Sulawesi crested macaques (M. nigra) are still exposed to the negative impact of human activity in the form of habitat loss affecting their socioecology (Kumara et al 2014;Singh et al 2001), ecotourism-related stressors and mortality rates (Berman et al 2007;Marechal et al 2011), and hunting for bush-meat impacting mortality rates (Kyes et al 2012;Palacios et al 2012;Riley 2007;Riley and Fuentes 2011). Indeed, many of these species are classified as being "endangered" or "critically endangered" as a result (IUCN 2019).…”