4. Episode 4

Newcomer Safi, a rare bongo antelope from the mountains of Kenya, is giving enthusiastic breeding partner Moti the runaround. Very soon the keepers realise why - it seems she may be about to give birth earlier than expected. Sunda gharial crocodiles Frank and Frankie need to have their blood tested - but taking a sample from one of the world's largest and most dangerous reptiles is easier said than done - and George the giant rat needs to have surgery after an X-ray pinpoints a huge lump of hard faeces in his stomach.