Dormouse Reintroduction Day 2019

by ZSL on

On the 18th June, 11 hazel dormice (Muscardinus avellanarius) were released into a woodland in Lincolnshire as part of the Natural England Species Recovery Programme, following a four-hour drive from London to the Lincolnshire county. The reintroduction was a big day for everyone involved, as dormice have not been released into this particular woodland for over 15 years. 

Close-up photo of a curled up dormouse being held

These hazel dormice had been quarantined at ZSL for 10 weeks, managed by the DRAHS (Disease Risk Analysis and Health Surveillance) team.  ZSL has been a part of the hazel dormouse Species Recovery Programme since 1999 and has played a key role in monitoring the health of captive-bred dormice released into the wild to help combat the decline of this species. Sadly, hazel dormice have become extinct from 17 English counties since the end of the 19th century, with populations thought to have fallen by a third since 2000 – a rate of decline equivalent to 55% over 25 years. Loss of woodland and hedgerow habitat, as well as changes to more traditional countryside management practices, are all potential factors which have contributed to this decline.

Photo of 2 members of the DRAHS team either side of the wire release cage with the dormice nest boxes visible inside
Tammy Shadbolt and Inez Januszczak from the DRAHS team standing by a soft release cage. The wooden nest boxes containing the dormice can be seen inside.

This is the Species Recovery Programme’s 28th dormouse reintroduction. The programme is a collaborative one, involving numerous other conservation organisations such as People’s Trust for Endangered Species (PTES), Natural England and Paignton Zoo. Over the last 25 years, more than 950 dormice have been released at 23 different sites.

The Lincolnshire Dormouse Group, who have monitored the wood since the last reintroduction, have welcomed a top up to the dormouse population which has appeared to have remained steady since the last release. 

The dormice are released into ‘soft -release’ cages; large mesh cages which are placed in various areas of the woodland. They will be supplementary fed for 10 days, allowing some time to adapt to their new wild surrounding after being in captivity. After 10 days the cages are opened, and the dormice are free to explore.

Photo of a woodland area with a dormouse nestbox attached to a small tree.
A dormouse nestbox, already set up in the woodland.

There are numerous nest boxes scattered around the beautiful woodland, which are regularly checked by the Lincolnshire Dormouse Group volunteers. During their time at ZSL, all the dormice were microchipped so that they can be identified in the future. Any dormice found are recorded by the National Dormouse Monitoring Programme (NDMP), so the population can be monitored long term.  Hopefully it won’t be long before some juveniles are found showing that this endangered mammal is breeding. 

Learn more about DRAHS

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