despite efforts by wildlife authorities, government, the zoo community, and non-governmental, organization, the extinction of a number of species and sup-species of these charismatic mega-vertebrates, a group of big mammals that have alway captured the imagination of mankind, seems to be inevitable. in situpopulations of the northern white rhinoceros (cer- atitherium simum cottoni), the eastern sumatran rhinoceros (dicerorrhinus sumatrensis harrissoni), or the javan rhinoceros (rhinoceros sondaicus) are down to 4, 13, and less than 50 individuals, respectively. each of thede populations faces a similar face to that of the western black rhinoceros (diceros bicornis longipes), which was declared extinct in 2006 [1,2]. the uncertain future of rhinoceros species and suo-species in situ-illustrates the importance of ex-situ breeding programs. whereas protecting natural habitat and eliminating other human-caused threats remain the highest priority, parallel development and application of assisted reproduction technology to product viable, healthy offspring in captivity with maximum genetic diversity is imperative.