Macaca fascicularis (crab-eating macaque) are native to south-east Asia and have been introduced into Mauritius, Palau (Angaur Island), Hong Kong and parts of Indonesia (Tinjil Island and Papua).
They are considered to be invasive, or potentially invasive, throughout their introduced range and management may be needed to prevent them from becoming invasive in areas such as Papua and Tinjil.
They are opportunistic mammals and reach higher densities in degraded forest areas, including habitats disturbed by humans. They have few natural predators in their introduced ranges.
Macaca fascicularis impact native biodiversity by consuming native plants and competing with birds for fruit and seed resources.
In addition, they facilitate the dispersal of seeds of exotic plants. Macaca fascicularis may also impact on the commercial sector through their consuming of agriculturally important plant species and damaging of crops.
Description:
Upper parts dark brown with light golden brown tips, under parts light grey; tail dark grey/brown and equal to head and body length. Crown hairs directed backwards; sometimes forming short crest on mid-line.
Skin is black on feet and ears, muzzle light greyish pink. Eyelids often with prominent white markings, white spots sometimes seen on ears. No perineal swelling. Males 3.5kg - 8.3kg; Females 2.5kg - 5.7kg.
Occurs in:
agricultural areas, natural forests, planted forests, range/grasslands, riparian zones, ruderal/disturbed, scrub/shrublands, urban areas
Habitat description:
Crab-eating macaques (Macaca fascicularis) inhabit a wide range of habitats including riverine, secondary and primary forest, forest periphery, mangrove and nipa swamp, coastal forest, and urban and agricultural settings, in both their natural and introduced range.
They have a preference for secondary habitats which have been disturbed by human activity and are highly adaptive to new environments. Occur from sea level to 1200m and can travel at least 1828m in their natural range.
General impacts:
Crab-eating macaques (Macaca fascicularis) may negatively impact biodiversity by eating the eggs and chicks of endangered forest birds. They compete with native birds for resources such as native fruits.
They may aggravate the negative effects of exotic plant species by consuming their fruits and aiding dispersal of their seeds. Macaques feed on sugar cane and other crops, affecting agriculture and livelihoods, and can be aggressive towards humans. Macaques may carry potentially fatal human diseases, including B-virus.
Uses:
In their natural range, crab-eating macaques (Macaca fascicularis) are occasionally used as a food source for some indigenous forest dwelling peoples. In Mauritius, they are sold to the pharmaceutical industry with a value of approximately US$1500 per individual, and in Angaur, Palau they are sold as pets.
Notes:
Natural predators of crab-eating macaques (Macaca fascicularis) include large carnivores (panthers and sun-bears in Java), snakes and possibly large raptors. Some primate taxonomists consider M. fascicularis to be more of a species group or superspecies, as it has a complex relationship with other species such as M. mulatto, M. cyclopis, and M. fuscata.
Geographical range:
Native Range: Mainland south-east Asia (including southern Burma), eastern Thailand, Cambodia, southern Laos and Vietnam, and Malaysia), Philippines, Indonesia (Sumatra, Borneo, Java, Bali, and eastern Lesser Sunda Islands). Known introduced range: Mauritius, Palau (Angaur Island), Hong Kong, Indonesia (Tinjil Island and Papua).
Introduction pathways to new locations:
- Acclimatisation societies
- Landscape/fauna “improvement
- Military
- Ship
Local dispersal methods:
Escape from confinement: The risk of pet crab-eating macaques (Macaca fascicularis) escaping and forming new populations is significant as many people import these animals to keep or sell as pets (Kemp and Burnett, 2003).
Natural dispersal (local): The home range of crab-eating macaques (Macaca fascicularis) varies greatly depending on the location and whether they are in their native range or an introducted range. In their native range the home range size may vary from between 50 hectares and 100 hectares.
The mean troop home range in their introduced range is estimated to be only 800 m² in Mauritius (Sussman and Tattersall, 1986, Carter and Bright, 2002). In their introduced range in Papua (Indonesia) the home range size may vary between 3 hectares and 22 hectares.
Management information:
Preventative measures: Plantations of Japanese red cedar (Cryptomeria japonica) appear to provide protection to native birds (and eggs) from the predation and scavenging of macaques. Quarantine measures need to be more effective in places such as Papua (Indonesia) to prevent the range expansion of the current population.
Physical:
In Mauritius live-trapping has been carried out for export and research. Socio-religious reasons may mean this solution is not appropriate. Animals may become trap-shy. Local communities in Papua and Palau have hunted macaques with some success.
Biological:
The immuno-vaccine Porcine Zona Pellucida (PZP) (which causes infertility in females) is currently being trialled in Hong Kong to investigate its use as a population control.
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