World’s most threatened frog breeds at London Zoo

Critically Endangered mountain chicken froglets hop into the world in time for Mother’s Day 

We're celebrating a conservation success after two Critically Endangered Mountain chicken frogs bred for the first time in five years in their brand-new custom-built home. 

Metamorphosing just in time for Mother’s Day, the six froglets are offspring from a new pair who recently moved into the Zoo’s newest experience - the Secret Life of Reptiles and Amphibians. 

Size of mountain chicken frogs

The huge frogs (tipping the scales at 360g, almost as much as a can of soup) arrived in their bespoke home which will open to visitors this Easter, and immediately got to work prepping for parenthood, with the huge male quickly digging a ‘bowl’ in the underground clay lined nesting chambers, showing off his skills to his new mate.  

Once enticed into the nest, the pair begins the hard work of prepping to welcome their offspring – producing a foam nest to lay their eggs into. The tadpoles develop in the foam nest and, uniquely, the mother lays thousands of unfertilised eggs for her offspring to feed on every one-to-seven days, ensuring that the young animals have the best start to life. The mothers may feed the tadpoles in the nest 10-13 times during their development, meaning she may produce an estimated 10,000-25,000 eggs.  

Our Curator of Reptiles and Amphibians, Ben Tapley said; “We are delighted at how quickly the mountain chicken frog colony have settled into their new home. Soon after they arrived, we spotted the female frog guarding her foam nest. 

“Mountain chicken frogs are incredible parents. The mother regularly visits the nest to lay unfertile eggs, which the growing brood will feed on, she also guards her nests, puffing up and using her body to defend her young from anything that gets a little too close.” 

The six, inch-long froglets, have some growing to do to reach the size of the enormous adults, and will play a key role in bringing this species back from the brink of extinction – a recent intensive survey to find the frogs in Dominica identified just 21 individual mountain chicken frogs.  

The frogs were once widespread across the Caribbean until a killer fungus was introduced to their remaining habitat on the islands of Montserrat and Dominica. A mass mortality event in the early 2000s was discovered - by a team including a ZSL scientist - to have been caused by chytrid fungus, which wiped out more than 90% of their population.  

In 2009, our conservationists along with other European zoos airlifted the last few mountain chicken frogs to safety in a last-ditch attempt to save the species from extinction, a dedicated facility was built and a coordinated EAZA breeding programme was established for the species. Visitors will come nose-to-nose with one of the world’s largest and most threatened frogs – as the family of Critically Endangered mountain chicken frogs at the Zoo will be visible for the first time.  

*Based on the average zoo admission prices for one or two adults with two children in relation to the family membership Direct Debit fee.