NAIROBI – Scientists racing to save the northern white rhino from extinction have released 10 more eggs from the last two females, which they hope will help create viable embryos that can be incubated by other rhinos who acted as surrogates.
None of the remaining northern white rhinos on Earth – a mother and her daughter – can carry a baby until term, so scientists want to implant the embryos in southern white rhinos instead.
The last male northern white rhino, named Sudan, died at the 2018 Ol Pejeta Conservancy in Kenya.
The northern white rhino once roamed East and Central Africa, but as with other rhino species, its numbers have declined due to heavy strokes.
Northern white rhinos – now the most endangered mammal in the world – have hairier ears and tails, are shorter and stubborn and have different genes than their southern cousins.
Scientists first harvested females a year ago as part of a team from the Ol Pejeta Conservancy, Kenya Wildlife Service, the Italian-based Avantea Lab, the Czech Republic Dvůr Králové, and the Germany-based Leibniz Institute for Zoo & Wildlife Research.
They produce three pure northern white rhino embryos that are now frozen. But the scientists realized that they needed to synchronize implanting embryos with the reproductive cycle of surrogate mothers. The more embryos they have, the better.
One potential hurdle is that people do not know how to detect when the time for insertion of the embryo is exactly.
Enter the romantic decoy.
A southern white rhino bull will be sterilized, transported to Ol Pejeta and released under possible surrogate mothers. His reaction will signal when they are on heat.
“Through his activities, we would be able to identify the exact time for embryo insertion,” team coordinator Jan Stejskal, from Dvůr Králové Zoo, told Reuters.
“We start early in the morning, the first female is immobilized and then the procedure takes about two hours,” Stejskal said of the egg harvest.
The eggs are so delicate that they have to be flown directly to a laboratory in Europe in a hand-held incubator by a scientist.
“If you want to start a population of the northern white rhino, one baby is not enough, you need as many babies as possible,” Stejskal said.
