This data set contains stacked detection matrices for 28 recorded mammal species across 115 sampling locations at the Stability of Altered Forest Ecosystems (SAFE) project site located in Sabah, Malaysian Borneo. Information for each camera trap sampling location, including spatial information and sampling effort is included. Data were collected in order to determine the contribution of carbon-based policies to biodiversity conservation in agricultural land-use mosaics. These data are essential to the development of the occupancy detection matrix. Data were collected in 2015 during a project which was included in the NERC Human-modified tropical forest (HMTF) Programme.