This study investigates the effects of habitat fragmentation on an Angola black-and-white colobus (Colobus angolensis palliatus) metapopulation in southern Kenya. 124 coastal forest fragments were surveyed in 2001. Fifty-five C. a. palliatus populations were found during this survey, (44% habitat patch occupancy), with an estimated national population estimate of 3,100 - 5,000 individuals. Colobus occurrence and density in this forest network was significantly linked to the spatial characteristics and quality of habitat patches. The heterogeneous landscape between habitat patches (matrix) was also found to be important, providing additional foraging habitat and connectivity between forest patches. The use of a spatially explicit metapopulation model (the incidence function model) provided a conceptual framework in which to explore future scenarios of habitat change. C. a. palliatus metapopulation persistence was found to be dependent upon the five largest forests in the network. Many of the colobus populations inhabiting unprotected forests were found to be on critical limits of population extinction. Population occupancy was also affected by the degradation or enhancement of the surrounding matrix.