Chester Zoo has announced the breeding of more than 30 rare animals. Highly endangered newts bred at the UK zoo have now been released into the wild at a secret location in Catalonia as part of an international effort to save the species from extinction.
The team has just introduced 32 Montseny brook newts to a mountainous habitat near Barcelona. More than 100 more are still living at Chester Zoo while they mature ready for follow-up releases. Montseny brook newts are chocolate brown, gold-speckled amphibians that grow to up to 10cm in length - roughly the size of a pack of cards. They are critically endangered, according to the IUCN Red List, and around 1,000 remain in the wild.
Secret release site and UV tracking
The release site is being kept secret to protect the newts from disturbance and from a deadly fungal disease that can devastate amphibian populations. The released newts have been given UV markers to track their movements and the success of the reintroductions.
Dr Gerardo Garcia, animal and plant director at Chester Zoo, has been involved with the Government of Catalonia’s Montseny Brook Newt Recovery Plan since its beginning. He said: "These newts are fascinating, and also quite cute. But they are extremely vulnerable. Their habitat is fragmented by roads, they are highly sensitive to water quality and they face the constant threat of illegal wildlife trade."
Genetic diversity and mysterious larvae
Despite their precarious situation, researchers have been encouraged by one unexpected finding - the newts' genetic diversity is surprisingly healthy for a species so close to the edge. He added: "Usually when numbers get this low, you'd expect genetic diversity to plummet. But research shows it's surprisingly good. That gave us a strong foundation for the project."
The species holds another mystery. Larvae are regularly spotted in the wild, but then disappear, only to re-emerge later as mature adults. Conservationists believe the newts may spend part of their lives in a hidden underground river system beneath the Montseny mountains.
Breeding program at Chester Zoo
At Chester, 12 breeding pairs continue to live in specially designed breeding pods, where keepers carry out regular health checks under strict biosecurity protocols. Ellie Bland, the zoo’s Ectotherms Keeper, oversees daily water checks, tank cleaning, headcounts and egg-checks. She said: "The females evolved to lay eggs in fast-running water, so they are experts at putting them in tiny hidden crevices – it’s not always easy to find them.
"They’re quite quirky. They are visual hunters that target aquatic worms and insects – I pipette feed them and they are very reactive to movement – so we have these huge eyes watching us while we work."
Mrs Bland said seeing the newts enter the river after months of careful monitoring in the zoo was a profound moment. She added: "It’s awesome seeing them swim free. Moments like this are why I wanted to work in a zoo in the first place."
The first newts to come to Chester Zoo arrived in 2017.
