A health check for our mountain chicken frogs
13 May 2026
Every year, the mountain chicken frogs at Jersey Zoo undergo a comprehensive health check, which is one of the requirements set by the European breeding programme when caring for this species in captivity.
The health check is quite a big undertaking for our veterinary team, who individually examine all 15 of these Critically Endangered frogs in one day.
The first port of call is a weight check, which we track over the years to make sure they are growing well. Our biggest females are reaching 650g! Females are supposed to be able to reach 1kg, but this has never been recorded in captivity, so we have high hopes for our females.
Next, we undertake an ophthalmic examination to make sure their eyes are in good condition and no cataracts are present. The team then carefully administer anaesthesia by using gas in a bag, so that we can give the frogs a closer inspection. The physical examination then continues, by taking their measurements to track their growth and body scoring. Next, we undertake x-rays and a blood sample, to check how their organs are functioning, as well as look for any skeletal abnormalities. The final check is an ultrasound, again to check organ functions, as this species is very prone to getting gallbladder stones. After all of this is complete, we reverse the anaesthetics and return the frogs to their homes.
The mountain chicken is one of only two native frog species in Montserrat, and they are the island's top endemic predator. They were once a popular, traditional Caribbean dish and are said to taste like chicken, hence the unusual name, "mountain chicken"!
These frogs have an unusual breeding strategy. To lay their eggs, females create foam nests underground and will purposely lay infertile eggs for the tadpoles to feed on. This is the only food tadpoles will accept!
Despite surviving hurricanes, volcanic eruptions and being hunted for centuries, the mountain chicken frog was driven to the brink of extinction by a deadly microscopic fungus.
Since 1999 Durrell has been working to bring mountain chicken frogs back from the brink.
At Jersey Zoo, we were the first organisation to successfully keep and breed mountain chicken frogs in captivity, and our captive population and management of the species have led to a greater understanding of its biology and ecology.
Our mountain chickens can be found in the Reptile and Amphibian House in an environment similar to the damp undergrowth they inhabit in the wild. Despite their large size, mountain chicken frogs are elusive and spend most of the day sleeping in burrows before venturing out at night to hunt.
They can be hard to spot as they like to sleep in their burrows, but if you listen carefully, you might hear their unique whooping calls!