17 May 2024

10 tiny rare hazel dormice have been given the all-clear by our wildlife vets, ahead of their release into the wild next month. 

Each 20-gram dormouse had a 10-minute appointment with wildlife vets from our Institute of Zoology during which their heart and lungs were checked with a stethoscope, and their eyes, ears, nose, teeth and fur examined. They were also microchipped and x-rayed to check their bones and overall health.   
Hazel dormice populations have decreased by a staggering 70% nationally since 2000, but ongoing efforts to restore their populations have seen more than 1,000 dormice reintroduced into 25 woodland habitats in 13 English counties since 1993. 

Wildlife vet Dr Clare McNamee monitoring heart and lung health of hazel dormouse as part of health check
Hazel dormouse ready for their health check with ZSL wildlife vets
ZSL wildlife vets reviewing X-ray of hazel dormouse
Hazel dormouse being given a health check by ZSL wildlife vets

Protecting UK Wildlife

The health checks are part of our Disease Risk Analysis and Health Surveillance team’s efforts to ensure that animals being released to the wild are fit and healthy enough to be released to the wild, and that there is no risk of them passing diseases onto local wildlife.   
The dormice will be heading to a secret woodland location this summer as part of the annual reintroduction programme led by People’s Trust for Endangered Species - bringing together ZSL, Natural England, Paignton Zoo, the Common Dormouse Captive Breeders Group, and this year Forestry England and The Greensand Trust – to rebuild populations of this native species. 

Hazel dormouse heart and lung health being monitored by wildlife vets as part of pre-release health checks
Hazel dormouse being measured as part of health checks with ZSL wildlife vets
  • Hazel dormouse close-up, dark circular eyes with rosy orange fur
    Reintroducing the hazel dormouse to British countryside

    Hazel dormouse

    By working together with our conservation partners, we've managed to successfully reintroduce over 1,000 dormice

  • Dormouse on a weighing scale at London Zoo, sitting in a plastic container.
    Essential wildlife health monitoring

    Wildlife Disease Risk Analysis and Health Surveillance

    Our DRAHS team provides essential wildlife health monitoring for conservation projects.

  • hedgehog_sitting_on_green_moss
    Making a difference for wildlife across the UK and Europe.

    Conservation in UK and Europe

    Remember the last time you saw a hedgehog rustling in the leaves? We're restoring wildlife across Britain and Europe.

  • Hazel dormouse sleeping
    25 May 2023

    Rare dormice get full health check-up before wild release

    Rare British hazel dormice have been given their final check-up by our vets ahead of their planned release into the wild next month - as part of our on-going conservation work to protect this tiny, vulnerable mammal, once common across England and Wales.

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    1 November 2022

    Red kite health surveillance

    Understanding unexplained red kite deaths in England, like poisoning , shooting and parasites.


From wildlife health monitoring to genetic research, as the original science-led conservation charity we are leading a fight for wildlife across the globe. Together we can make a difference, join us on our journey to build a better future.