sentences:  Their rarest animals are northern white rhinoceros, which are now on loan (Last Chance to Survive Program) to Ol Pejeta Conservancy in Kenya.The Zoo is the only one in the world where northern white rhinos have successfully given birth, with the last calf being born in 2000.The Zoo was established in 1946 on an area of 6.5 hectares to house a small collection of local fauna and was originally known as the East Bohemian Zoological Garden ().