Eva & Emily Re-Introducing Harvest Mice in Devon

Aim

We're two teenagers from Devon who've spent 3 years breeding endangered harvest mice & are now ready to re-introduce them back into the wild

Update 1st September: Five days after being released, we can see on the trailcams that our mice are coming and going freely from the soft release enclosure = very exciting. We will keep topping up their food and water as long as they keep coming back

MAJOR UPDATE 27th August: Chris Packham came to our mouse release yesterday and it was the best day of our lives 🤩🤩

One of the mice escaping up Chris's arm instead of going into the soft release enclosure

There's an article about it in the Guardian here:

https://www.theguardian.com/environment/2025/aug/28/im-proud-of-them-going-out-into-the-world-young-naturalists-on-their-quest-to-save-harvest-mice 

And on Newsround: https://www.bbc.com/newsround/articles/cn475gy5xxno

And on Woman's Hour: https://www.facebook.com/share/r/19hgwLr6DB/?mibextid=wwXIfr

Us preparing to speak live on BBC Radio 4's Woman's Hour the day after the release. 

Thank you to everyone who supported the crowdfunder and made our dream of reintroducing harvest mice come true.

UPDATE 22nd August: Thanks to Chris Packham posting about our project (which
blew our minds) we have now raised 91% of our total with 11 days to go. Yesterday, a local carpenter made our soft release enclosure - it's almost ready, he just needs to add the tiny holes so the mice can come and go but snakes and rats can't. Now we have the funds to buy them, we are going to buy two trail cameras to attach to the enclose, so we can see what happens. Thanks so much to everyone who has donated, we are so, so happy! From Eva and Emily

Hello. We are Eva and Emily, both aged 13, from Tiverton in Devon. We have been breeding  harvest mice in our garages and bedrooms for the past three years and we are now ready to re-introduce this important missing species back into the wild this September.

To release 220 mice this September and another 50 next spring, we need to raise £4050. That's £15 per mouse.

Some of our mice enjoying their wheel: we give all our mice wheels so they can keep active while they're in captivity 

Here's an article about our project in Devon Live: https://www.devonlive.com/news/devon-news/devon-girls-quietly-leading-revolution-10284212

Harvest mice are a vital part of Britain's ecosystem, as they are a prey species on which other creatures like owls, hedgehogs, weasels and foxes depend. But over the last few decades, their numbers have collapsed due mainly to loss of their habitat. They are called "harvest" mice because they make their nests on tall grasses like wheat and so used to be seen when farmers brought in the harvest in Autumn. But now modern farming techniques mean farmers can have more than one crop per year which mean there isn't time for the mice to make their nests and reproduce any more.

Inspired and supported by world-famous ecologist Derek Gow, who lives near us in Devon, we have been breeding harvest mice for three years. We bred 68 mice in our first 18 months and they went off to be released along with other mice bred by Derek's team at a nature reserve in Cheshire. Now we have bred about 100 more (we don't know exact numbers because they hide in their straw in their tanks) and these will be released this September, along with about 150 from Derek's team.

Us with Derek Gow

The release site is a new nine acre "wildlife recovery zone" just outside Tiverton in mid Devon, which is community-owned by Wild Tiverton CIC = the organisation  collecting the funds for this crowdfunder.

As well as breeding the mice, we have also been working for the last year with the Tiverton Tree Team and Tiverton Scouts  preparing the site: we've planted cocksfoot grass (the mice's favourite for building their nests), built dead hedges, planted a living hedge and dug a pond to provide water for the mice when they are living freely. There's an article about our work preparing the site here: https://www.devonlive.com/news/devon-news/gallery/tiverton-volunteers-plant-664-trees-9958646

Digging the pond

Planting a living hedge around a dead hedge, to provide maximum habitat, hiding places and food for the mice


We have paid for all the costs so far with a £500 grant we were awarded from Devon Environment Foundation, plus £100 Eva's Mum won on a sweepstake competition. This has paid for tanks, food, wheels, the pond, cocksfoot seeds etc over the last two years.

Us doing a presentation about our mice to the "eco council" from a local primary school who came to visit

Now we need to raise another £3450 to pay for: approx 150 mice from Derek's team to add to the 100 we've bred, building a large soft-release pen for the mice to be released into (it will have tiny holes so they can come and go, but predators like rats and foxes won't be able to get in), setting-up three trail cameras, food for the mice over the next year (may not be necessary if they all run off), buying another 50 mice from Derek for a "top-up" next spring.

This is the total money we need to hopefully complete the re-introduction of this missing species back into the mid Devon landscape, where they belong.

Eva was on Blue Peter, briefly, as her idea WILD PETS was runner-up in their EarthShot competition. WILD PETS is about encouraging other children to breed endangered species for reintroduction and is Eva's next big project

Eva is going to write up the results for an HPQ (like a GCSE but about your own project) and we will also let anyone who supports us know what happens. We will know whether we have been successful when we check to see whether there are any nests in Autumn 2026. We can't imagine how thrilled we will be if we find one!

Thanks for reading and we hope you are able to support these mice.

Funding method

Keep what you raise – this project will receive all pledges made