by Hilary Koll
2nd January 2025
In my series of blog posts about Harvest Mice (see links below), I outlined the journey taken to learn more about Harvest Mice – with a (somewhat hopeful) view to potentially releasing captive-bred mice in our field. Harvest Mice are classified as ‘near-threatened with extinction’ in Britain and I learnt of other reintroduction programmes to support them in similar habitats around the country. In this final post I would like to update you on how my distant dream finally became a reality.
As I mentioned in my first post, in the field we are ‘re-naturing’, a thick leaf-litter and a range of different tall grasses, including cocksfoot, offer a suitable and appealing habitat to Harvest Mice. Research showed that these delightful creatures were not present in our local vicinity and, following my visit to another reintroduction programme in the Yorkshire Dales I enquired about whether it would be possible to do the same in our field. I contacted the Derek Gow Consultancy, based in Devon, well-known for breeding animals for reintroduction programmes, to find out what it would cost to release an appropriate number of genetically diverse mice into our field. With the breeding location being a considerable distance from our North Yorkshire field, the cost – for breeding the mice, transporting and releasing them on two separate occasions, and with follow-up surveying – was more than we had expected.
Fortunately, we were advised that there were grants for such projects and so contacted the North York Moors National Park – as our field lies within its boundaries – last December. After submitting an application for the Farming in Protected Landscapes (FiPL) grant early in the new year, by February 2024 we had been given the go ahead!
| Farming in Protected Landscapes (FiPL) |
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| If you are a landowner or land manager in the North York Moors National Park and could benefit from funding, please do take a look at this information around the Defra-funded Farming in Protected Landscapes Programme. The programme only runs until March 2025 so in the first instance, contact Dave Arnott, lead FiPL Officer on 01439 772589 d.arnott@northyorkmoors.org.uk or Corey Rathbone, FiPL Assistant Officer on 01439 772537 for more information. |
All we then had to do was to wait for the mice to arrive in early summer, while the Derek Gow Consultancy began to breed the mice. A cold and wet spring seemed to slow the reproduction rate of the breeding pairs so it was not until mid-July that our first batch of 100 or so mice were ready to make the journey.
With the help of volunteers from the Whitby Naturalists Club, the Yorkshire Rewilding Network, the North York Moors National Park and other interested people – including Harvest-Mice researcher Derek Capes who had been such a help to me – the first of two reintroduction days arrived.
The mice were delivered in the boxes they were bred in, each one well provided with bedding, food and water with between 15 and 20 in each box. It was fascinating to see the nests they had made. To ensure an even distribution across the field suitable release spots had been marked with a tall cane and flag as marker. One by one the boxes were carefully carried and placed next to a cane, the lid was removed and the box gently positioned onto its side. Care was taken to put the opening to face away from the prevailing wind (and forecast rain!) and tuck the box into the grass and vegetation. Some mice were raring to go, others seemed more cautious. However, there was no need to rush them, this was a ‘soft release’ and the boxes were left in situ for several days so that the mice had somewhere safe to go with food and shelter until they were able to make a new nest and home for themselves.
Whilst we were careful not to handle the mice at any point some seemed quite ‘chilled’ and all the volunteers got a good view. Everyone involved enjoyed the chance to see such delightful and normally shy creatures close up and agreed it was a rare and special privilege. We were lucky enough to have filmmaker Emily Ramsden with us to document the events and you can watch her excellent short film by following the link below. After releasing the mice into the field refreshments were sold, raising money for our local Whitby Swifts group.
Following a second release, by mid-September over 300 harvest mice had been released into the field, much to the delight, no doubt, of our resident barn owls!
During the winter months, we will undertake surveys to search for nests and will be analysing barn owl pellets for evidence of the mice. It’s hoped that the population will grow and eventually spread into the wider area including along the neighbouring Cleveland Way coast-path.
Finally, I’ll leave you with some photos of the release, with some adorable mouse images and the link to Emily Ramsden’s video which can be found here … Enjoy!
Useful links:
An unexpected journey (Part 1)
An unexpected journey (Part 2)
An unexpected journey (Part 3)
Farming in Protected Landscapes (FiPL) Year 2 Update
[Image Credits: Steve Mills, Debbie Davitt]