'Bringing Harvest Mice Back to Ealing' is a Rewild London Fund project that London Wildlife Trust is thrilled to be involved in. It has been made possible with funding from the Mayor of London and Amazon’s Right Now Climate Fund. 

Perivale Wood is the UK’s second oldest nature reserve, and the last place harvest mice were sighted in Ealing before becoming locally extinct. It has been managed by the Selborne Society since 1902 and is a Site of Metropolitan Importance for Nature Conservation (SINC) and statutory Local Nature Reserve. The Wood includes ancient oak woodland and neutral grassland, supporting a great diversity of animal and plant life.

Harvest mice became locally extinct in Ealing over four decades ago, with the last recorded sighting at Perivale Wood in 1979. Habitat loss and fragmentation are likely to be the main cause of their loss from the borough. Habitat loss is estimated to have resulted in the British harvest mouse population declining by 70% since the 1970s.

More than 1650 harvest mice have now been released across sites in Ealing with Perivale Wood becoming the fifth release site. This project links up those release sites with new and improved suitable habitats at Perivale Wood via dispersal routes along the canal and railside, enabling the harvest mouse population to expand its range and thus making the population more likely to expand and survive any habitat stress caused by events such as a drought.

This brings the Mayor’s total investment in rewilding London to over £2.4 million since 2022, which includes £750,000 from Amazon’s Right Now Climate Fund. In total, the Rewild London Fund will have helped to create or restore over 350 hectares of wildlife habitat - the equivalent of nearly 490 football pitches - across the capital, bringing nature back into the city for all to enjoy.    

David Mooney, CEO at London Wildlife Trust said: “London Wildlife Trust is proud and excited to support this excellent project to reintroduce the iconic harvest mice into Perivale Wood, Ealing. The wildlife corridors created through habitat improvements will crucially link new and existing populations, helping to bolster the species' resilience in the Borough.”

Richard Goddard, Chair of the Selborne Society commented:

‘It’s fantastic to be welcoming harvest mice back to Perivale Wood after a 45-year absence. We’ve been working hard to enhance existing habitats at Perivale Wood and improve connections to the nearby release sites at Paradise Fields and Horsenden Meadows.

I’m excited to see the improvements we’ve made to small mammal habitats at Perivale Wood, including the creation of a new pond; this will soon provide reed beds, a habitat favoured by harvest mice and many other species. We are hugely grateful to all the Selborne Society volunteers who put in more than 2,000 hours of voluntary work in 2023 to improve our habitats, to Ealing Wildlife Group for bringing us into this rewilding initiative and the volunteers at Horsenden Farm for their incredible hard work breeding the mice in captivity in preparation for their release. This has been the perfect way to celebrate #NationalMammalWeek and #ForgottenMammals.

Dr Sean McCormack, vet and Chair of Ealing Wildlife Group commented:

It's been really fantastic to see wilder habitat types emerge in the past few years through our collaborative work with Ealing Council, meaning species that have previously been pushed to the edge now have the opportunity to return. Our 'Rewilding Ealing' initiative has seen not only Britain's smallest native rodent, the Harvest Mouse reintroduced, but also our largest, the Eurasian Beaver. Both projects have now been helped by the Mayor's Rewild London fund. And these projects are not just about rewilding habitat and reintroducing lost species, but also about rewilding people. By inviting our local communities to take part we've seen incredible engagement and a sense of pride and guardianship emerge for our green spaces. We're delighted to expand our Harvest Mouse project to the wonderful new habitats created at Perivale Wood.
 

Zak Watts, Amazon’s International Sustainability Director, said: “Bringing nature back to the communities where we live and work is a core purpose of Amazon’s Right Now Climate Fund. Thank you to all the experts and volunteers who have been working hard over the winter to rewild Perivale Wood and prepare for the harvest mice introduction. Local projects like these are key to improving our capital’s biodiversity challenge and helping Londoners enjoy and connect with nature.”