Staff at the Kenyan wildlife park which is home to the last two northern white rhinos left on earth express caution on the prospects of efforts by scientists to use in-vitro fertilisation (IVF) to help save this species from extinction. "Even if we were successful this year to implant an embryo from the pure northern white rhino we would still have to wait for a year and a half, about 18 months which is the normal gestation period," says Samuel Mutisya, Head of Research and Species Conservation at central Kenya's Ol Pejeta Conservancy, where the two northern white rhinos, Najin and her daughter Fatu, live under 24-hour protection. "There is no data to look back to in terms of the success rate for IVF process of rhino reproduction because as I said this is a first ever." IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES