Two more rare black-footed ferrets have been successfully cloned in the United States, the country's Fish and Wildlife Service announced.
The ferrets were cloned from the same genetic material as Elizabeth Ann, the world's first cloned black-footed ferret born in 2020.
Noreen and Antonia were born back in February, but the organisation announced the news on Thursday, local time.
Both are healthy and continue to reach expected development and behavioural milestones.
Noreen was born at the National Black-footed Ferret Conservation Center in Colorado, while Antonia resides at the Smithsonian's National Zoo and Conservation Biology Institute in Virginia.
All three ferrets were cloned from tissue samples collected in 1988 from a black-footed ferret known as Willia, stored at San Diego Zoo.
The application of this technology to endangered species addresses specific genetic diversity and disease concerns associated with black-footed ferrets that have been endangered since the 1960s.
All black-footed ferrets alive today, except the three clones, are descendants of the last seven wild individuals.
Besides genetic bottleneck issues, diseases like sylvatic plague and canine distemper further complicate recovery efforts.
Cloning and related genetic research could offer potential solutions, aiding concurrent work on habitat conservation and reintroducing black-footed ferrets into the wild.
Efforts to breed Noreen and Antonia will be made once they reach productive age.
Elizabeth Ann remains healthy at the National Black-footed Ferret Conservation Center in northern Colorado, exhibiting typical adult ferret behaviour.
Planned efforts to breed Elizabeth Ann were unsuccessful due to a condition called hydrometra, where the uterine horn fills with fluid.
Her other uterine horn was not fully developed, which is not unusual in other black-footed ferrets and therefore not believed to be linked to cloning.
Elizabeth Ann otherwise remains in "excellent health".
In addition to cloning efforts, the service is continuing work to recover the species in the wild.
