16 Feb 2023

“The animal and plants we care for here at Chester Zoo help to conserve their species in many ways.”

Lead Conservation Scientist, Dr Leah Williams talks about two areas of our Population Biology work at the zoo.

Dr Leah Williams
Breeding Programmes

By keeping animals alive and well across zoos and aquariums, they act as ‘insurance’ populations for species that are protected, providing a safety net in case their counterparts in the wild become extinct.

To do this, we carefully manage conservation breeding programmes across zoos in Europe through endangered species breeding programmes, which are coordinated through EAZA (the European Association of Zoos and Aquaria). Different species have breeding programme managers that help to maintain their populations in zoos by communicating regularly with different zoos and aquaria, providing recommendations such as where animals should be moved to and which might make good partners for breeding. These efforts help to ensure that the animal populations in zoos and aquaria remain stable and healthy and maintain genetic diversity over the long-term.

Here at Chester Zoo, our staff coordinate over 15 conservation breeding programmes and the animals at the zoo contribute to over 100 more.

Population Monitoring

By studying animals and plants in zoos we can learn things about them that would be impossible to discover in the wild, and we can also develop innovative ways to monitor their wild cousins.

For example, so little was known about the Bermuda skink until our teams began to study them as part of a new breeding program. We’ve now discovered so many new things about this species that may help to protect them in the wild.

Bermuda skink
Bermuda skink fitted with a radio tracking ‘backpack’ will which monitor their activity on the island.

Knowing how many animals and plants remain in the wild and where they are found, are vital pieces of information for designing and implementing conservation actions and strategies to protect them.
Counting and monitoring wild populations can be very challenging, especially for species that are very rare or difficult to find. We are always developing new methods and techniques for this population monitoring, and this is where our zoo animals can really help.

For example, ‘bioacoustic monitoring’ is a relatively new method that uses the sounds animals make to monitor their populations in the wild. To do this, tiny sound recorders (called passive acoustic monitoring devices) are set up over large areas of habitat to record any animal sounds. Many animals produce calls or songs to communicate with each other, these are often specific to the species, so by recording these calls we can identify if a species is present in an area.

In some cases, we can also calculate how many individuals there are and, amazingly, even their age or gender. However, we first need to know what different species sounds like: this is where our zoo animals save the day!
By recording the songs and calls of known animals in zoos, we can train specialised computer software to identify the species in our recordings from the wild. We are currently doing this with several species, including the critically endangered Javan green magpie, to find out how many remain and where they are.
When you next visit the zoo, think about listening out for all the sounds the animals make as well as watching them!


Become a scientist for the day! Grab your science journal and discover our five WONDERLABS to learn loads about the incredible science we do to prevent extinction!

18 February – 5 March