Vials of endangered species cells being stored safely to enable regeneration.

Vials of endangered species cells being stored safely to enable regeneration. Photo credit: Eva-Maria Broomer.

Can you imagine waking up one morning to a world where the wind blowing over the African soil has erased the last elephant footprint? Where our planet is no longer home to rhino, leopard or mountain gorilla? Or a world where the last giant ibis has taken its final flight? We are facing the reality of only seeing these animals, and countless more,  as pictures in books – knowing they will never return.

But, what if we could change the future of this story? Nature’s SAFE, one of Europe’s only charitable regenerative living cell banks, is dedicated to saving animals from extinction and rewriting the future of our endangered species.

Nature’s SAFE is capable of preserving animal reproductive tissue and cells in a way that maintains their viability for revival; providing the opportunity to support conservation breeding efforts by securing founding populations with the ultimate aim of restoring these declining or even extinct species.

Working in partnership with the European Association of Zoos and Aquaria (EAZA) and with vital support from Chester Zoo, Nature’s SAFE offers a unique piece of the puzzle to solve our extinction challenge. Housed in a specialist lab in Shropshire, UK is the beginning of the safeguard of our planet’s biodiversity.



What sets us apart and why science should give us hope

Nature’s SAFE is a science-led charity that uses cutting edge technology to store samples in a way that maintains viability for future regeneration. Using species-specific specialised processes and reagents, Nature’s SAFE can cryopreserve live cells at -196 oC. Nature’s SAFE stores both gametes (reproductive cells) and somatic cells (non-reproductive cells) from a range of species – not an easy task when our tanks contain a range of samples from cheetahs to frogs and each species can require different processing methods. Following the castration or death of an animal, Nature’s SAFE can harvest and preserve semen from the testes. After processing and storage, semen can be thawed and regenerated for use in assisted reproductive technologies to produce pregnancies in endangered species.

Rhiannon processing samples of endangered species in the Nature’s SAFE lab

Rhiannon processing samples of endangered species in Nature’s SAFE lab. Photo credit: Tullis Matson.

We are developing techniques to collect mature egg cells from ovaries of female specimens of endangered species, supported in part by The Rhino Fertility Project at the University of Oxford. Nature’s SAFE can also indefinitely preserve live testicular and ovarian tissue. Our goal is to develop multi-species protocols to enable the generation of sperm and eggs from stored reproductive tissue.

Finally, Nature’s SAFE processes and stores skin cells from deceased endangered animals. From these skin cells, we believe we will be able to generate naïve cells (called induced pluripotent stem cells) which can be directed to grow into any cell type. Skin cells have been isolated and grown from many species including beavers, porcupines, Asian elephants and loggerhead sea turtles. Naïve induced pluripotent stem cells have been generated for multiple species including orangutan, zebrafish and prairie voles. Our aim is to generate reproductive cells from our stored skin cells for use in endangered species breeding programmes.

Every sample we preserve today can be used in the future to broaden the genetic diversity of species to not only halt, but also reverse biodiversity loss.


Our aims and targets

In order to provide sufficient genetic variation to enable a species to survive, we need to bank 50 unique samples for each species. This is a colossal number of samples, and we know we cannot do it alone! Our vision is to have Nature’s SAFE hubs on each continent, providing the capacity and expertise to bank as many samples as possible. Recently, the technique of cryopreservation of reproductive tissue has been demonstrated by the successful birth of a Prezwalski horse 40 years after cells were frozen. The critically endangered black-footed ferret has had a new lease of life when cells frozen from a female who died in the mid-1980s have been used to regenerate her genetic line. The ferret, named Elizabeth Ann will be used in breeding populations for species reintroduction programmes. These success stories empower our vision and reaffirm the work we are doing.



Nature’s SAFE is endorsed by the European Association of Zoos and Aquaria (EAZA), the membership organisation of leading zoos and aquaria in Europe and Western Asia, Chester Zoo – one of the UK’s leading zoos for conservation, have played a key role in Nature’s SAFE since its inception (Chester’s Head of Science, Dr Sue Walker, is also a co-founder of Nature’s SAFE).

We support and are supported by The Rhino Fertility Project, based at the University of Oxford and headed by our Chief Scientist Professor Suzannah Williams. Ol Pejeta Conservancy – home to the remaining two northern white rhino and Gemini Genetics, a UK-based animal tissue bank are also close partners to Nature’s SAFE.

The scope of this mission has the potential to completely re-frame the extinction crisis. We believe it is possible to save animals from extinction and we are here to help us all write a legacy and a future we can be proud of.

We are passionate about building a community of people who are as dedicated to conservation and saving our animals as we are. The extinction clock is ticking, so whatever you are able to do – however small it feels to you, makes an enormous difference. There are a number of ways you can help us achieve our goals, such as:


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Rhiannon is a veterinary surgeon who is dedicated and determined to conserve biodiversity. She studied at the University of Nottingham obtaining a BVetMedSci (Hons) degree; her dissertation focused on reproductive dysfunction in captive female great apes. Rhiannon went on to complete both BVM and BVS degrees and joined the Royal College of Veterinary Surgeons in 2012.

Following experience as a veterinarian in first opinion small animal and wildlife practices, she was appointed as a Senior Veterinary Inspector for the Animal and Plant Health Agency, focusing on welfare and notifiable disease surveillance.

Returning to academia, Rhiannon worked as a research and teaching assistant at the University of Nottingham, School of Veterinary Medicine and Science and was awarded Wellcome Trust funding to conduct a MRes degree investigating the influences of environmental contaminants on adrenal gland development.

Rhiannon was then awarded an Adapting to the Challenges of a Changing Environment Doctoral Training Programme PhD studentship funded by the Natural Environment Research Council at the University of Liverpool and became a Chester Zoo Conservation Scholar.

Her research focuses on the physiology behind social behaviour and factors that may influence this, and reproduction and welfare in captive endangered cooperatively breeding mammals.

Rhiannon is a co-founder of Nature’s SAFE.