Complex sentence: The Western subspecies of the Black Rhino was last recorded in Cameroon but is now considered to be extinct, however some of the other subspecies have been introduced again into Botswana, Malawi, Swaziland and Zambia.
Split into simpler sentences: The Western subspecies of the Black Rhino was last recorded in Cameroon but is now considered to be extinct. However, other subspecies were introduced again into Botswana, Malawi, Swaziland and Zambia.