Four rare, northern white rhinos, half the known population left in the world, will leave a Czech zoo for Africa tomorrow in a last-ditch bid to save the species from extinction.
The Dvur Kralove zoo in northern Czech Republic, will transfer the rhinos to Kenya's Ol Pejeta conservation area and hope they breed in the wild, despite criticism from some conservationists who argue the plan is too dangerous.
Only eight northern white rhinos survive in captivity -- six in Dvur Kralove and two in San Diego, California. Four rhinos living in the wild in Africa have not been seen since 2006, raising fears the animals in captivity are the last of their kind.
"All the attempts, either here or in San Diego, to keep the species permanently from extinction, have not worked," said Pavel Moucha, chief zoologist of the Dvur Kralove zoo, who has cared for the animals for years.
"With only one rhino born in captivity in 10 years you can only just postpone the end," she told Reuters.
White rhinos are the largest land mammals after elephants and typically live in herds of up to 14 animals. The numbers of the northern subspecies have plummeted from an estimated 500 in the 1970s due mainly to poachers.
The Czech zoo first got the white rhinos in 1975 when a male and female arrived from Sudan at the ages of 2 and 3. Zoologists have tried to get the animals to breed but after initial success there has been only one birth in the past 10 years.
While zoo officials hope a return to the wild will spur successful mating, opponents say the plan puts the animals at risk because they have spent all of their lives in very different conditions than those they will experience in Africa.
"The results of such an undertaking are unpredictable and (we) do not believe that any significant conservation benefits will happen," said the European Association of Zoos and Aquaria.
A Boeing 747 will transport two males, Sudan, 37, and Suni, 30, and two females Najim, 20, and her offspring Fatu, 9 in containers specially equipped for the 2-tonne animals.
Zoologists at Dvur Kralove have also cut off the rhinos' almost metre-long horns to protect the animals in transit, Moucha said. The horns will eventually grow back.
Moucha said extremely difficult and uncertain breeding in man-made conditions has forced zoologists to carry out their risky plan to get the rhinos to breed more actively in the wild.
Females reach sexual maturity at the age of 6 to 7 years while males reach their peak around 10 to 12.
The zookeepers predict it will take up to two years for the animals to adapt to their new home in Africa but say their genetic memory of life in the wild should outlast one or two generations of captivity.
"At this age Fatu is quite ready to have offspring," Moucha said.
Officials also say the Kenyan reserve is well-guarded against poachers, something that could give the animals a fighting chance. Poachers covet rhino horns because they can fetch up to hundreds of thousands of dollars on the black market.
The zoo plans to keep the horns it has sawed off before the trip for lectures but already has had to rebuff requests for the material, considered a powerful aphrodisiac in parts of Asia.
"The craziest offer we got was to sell one kilogramme for 3 million crowns ($165,000)," said Moucha.