Niokolokoba is a great reserve, I did'nt expect such a great range of species in Senegal. I have visited Simenti twice with West African Tours travelling from The Gambia once in 2006 and then again in 2008. On our second visit the species list included Leopard, Roan Antelope, Hippopotamus,Kob, Oribi, Waterbuck, Ground Hornbill, Black Crowned Crane, Saddle-billed Stork and Lion. We missed Hunting Dog and Chimpanzee (but we found fresh nests).
This park is a short / cheap flight from the UK and has great wildlife, some interesting villages and Simenti makes a great base.