The survey of elephants in Bayang-Mbo Wildlife Sanctuary using the dung count method. The survey took place from November 2006 to May 2007.
A visit by the same author (Greengrass) in early 2016 showed elephants still to be present in the North of the Reserve.
Source:Greengrass, E.J., and Maisels, F. (2007). "Conservation of the Nigerian-Cameroon Chimpanzee P. t. vellerosus(and other mammals) in and around the Banyang-Mbo Wildlife Sanctuary, South-west Province, Cameroon." Cameroon