Nairobi, Aug 18 – Twelve months after the groundbreaking first harvest of eggs from the remaining last two female northern white rhinos, an international team of scientists and conservationists was today able to extract 10 more ova from the pachyderms in a bid to save the species from extinction.

The team extracted the eggs from the two individuals, Najin and Fatu, in the third-ever ovum pick up procedure in northern white rhinos at Ol Pejeta Conservancy in Kenya.

The animals were placed under general anaesthetic and 10 immature egg cells (oocytes) – two from Najin and eight from Fatu – were harvested from the animals’ ovaries using a probe with a movable needle guided by ultrasound. The anaesthesia and the ovum pickup went smoothly and without any complications, according to a press release issued by the conservancy.

The oocytes were airlifted immediately to the Avantea Laboratory in Italy. They will in the coming days be incubated and matured, fertilized with sperm from already deceased northern white rhino bulls — hopefully leading to viable northern white rhino embryos that will be stored in liquid nitrogen alongside the three embryos generated in the previous procedures.

The procedure on August 18 was conducted several months behind the original schedule of BioRescue, the international consortium led by the Leibniz-IZW and partially funded by the German Federal Ministry of Education and Research. The COVID-19 pandemic has severely impacted the project and its partners. Travel restrictions and contact prohibitions prevented work from taking place in European zoos and Ol Pejeta Conservancy.

The plan is to select a group of southern white rhinos at Ol Pejeta Conservancy from which a female could serve as a surrogate mother for the northern white rhino embryo.

The partners have agreed on a procedure of sterilizing a southern white rhino bull. The bull, which has already produced multiple offspring, is crucial to indicate oestrus and to create an ideal hormonal environment in the potential surrogates. To achieve the best possible results for work with pure northern white rhino embryos, the team relies on experience from similar embryo transfer procedures in southern white rhinos that have been performed in order to address reproduction challenges in European zoos.

The project is supported by the Kenya Wildlife Service and country’s Ministry of Tourism and Wildlife.