Macaque China reported in the journal "Cell" the creation of two crab-eating macaque monkey clones, named "Zhong Zhong" and "Hua Hua", using the complex DNA transfer method that produced "Dolly" the sheep, for the first time. As of 2005, the authors of "Mammal Species of the World" recognized the following species and species groups, aside from the white-cheeked macaque which was described in 2015: Later studies disputed some of the species groupings. For example, Li, "et al", based on DNA testing, do not recognize the "M. fascularis" group. Rather, they place the crab-eating macaque within the "M. mulatta" group and the
Celebes crested macaque Paignton Zoo are among a number of mostly European zoos which hold "ex-situ" breeding populations of this animal. Since 2006, the "Macaca Nigra Project" has been studying the biology and promoting the conservation of this species. The project, a collaboration between the German Primate Center and the Bogor Agricultural Institute, is run by Antje Engelhardt and located in the Tangkoko reserve, home of the biggest crested macaque population remaining in the species' original distribution range. Nevertheless, despite being critically endangered, crested black macaque are still being hunted down and slaughtered. Crested black macaque is considered a delicacy by local residents.