Complex sentence: They are found in Niokolo Koba National Park in Senegal and in two sites in Nigeria where only two small populations are left, one in Kainji Lake National Park and the other in Yankari Game Reserve.
Split into simpler sentences: They are found in Niokolo Koba National Park in Senegal and two places in Nigeria. In Nigeria, there are two small populations left, one in Kainji Lake National Park and another one in Yankari Game Reserve.