The Nigerian Conservation Foundation ( NCF ) took over management of the sanctuary in 1987 .
The Nigerian Conservation Foundation ( NCF ) extended it to 114 km by adding a 1.6 - kilometre - wide ( 1 mi ) buffer zone .
The Nigerian Conservation Foundation ( NCF ) took over management of the sanctuary in 1987 , and extended it to 114 km by adding a 1.6 - kilometre - wide ( 1 mi ) buffer zone .