Conservation Status : LEAST CONCERNCommon Name : Crab - eating macaque , Balinese macaqueScientific Name : Macaca fascicularisType : MammalDiet : insects , small reptiles , fish , crabsLength : 38 - 55 cmWeight : 5 - 9 kgThe crab - eating macaques , also known as the Balinese macaques , are monkeys that inhabit the Ubud Monkey Forest in Bali . These macaques have greyish - white fur covering their body and small patches of yellow fur cover the top of their heads and shoulders . They are opportunistic omnivores and have tails longer than their bodies . In the Ubud Monkey Forest , these macaques live in five different groups , with each group occupying a different area in the forest . Unlike the crab - eating macaques living in other regions , the macaques in the Monkey Forest get their food from the forest staffs and tourists , which makes it possible to see obese Balinese macaques . Outside of the forest , these macaques , however , are not viewed as sacred . In fact , they are considered an invasive species in places such as Hong - Kong and western New Guinea as they harm the local biodiversity . References : Ong , P . & Richardson , M . ( 2008 ) . " Macaca fuscicularis ". IUCN Red List of Threatened Species . Version 2008 . International Union for Conservation of Nature . Retrieved 4 January 2009 . " Macaca Fascicularis ( Nicobar Crab - Eating Macaque , Nicobar Cynomolgus Monkey , Nicobar Long - Tailed Macaque ) ". Iucnredlist . Org , http : / / www . iucnredlist . org / details / 12551 / 0 .