There were once 9 subspecies of tigers: Bengal, Siberian, Indochinese, South Chinese, Sumatran, Malayan, Caspian, Javan and Bali. The last 3 are extinct, one is extinct in the wild, and the rest are endangered.

Hugh Hefner funded some research in the 1980s that identified a subspecies of rabbit that dwells in the Florida Keys. The species was named after Hefner; its Latin name is Sylvilagus palustris hefneri.