Harvest mice have been released into the wild in Ealing by a wildlife conservation group as part of a plan to reintroduce the species to the area. 

Kicking off its ‘Rewilding Ealing’ initiative, Ealing Wildlife Group released 25 mice earlier this month in the first stage of its 18-month long programme to reintroduce the mammal.

The group teamed up with Calderglen Country Park who bred the mice and brought them down from Scotland.

Founder and chair of EWG Sean McCormack and other volunteers carried out an assessment last year to check if the species was extinct by looking for nests in suitable habitats.

But they found no evidence of the distinctive spherical balls of woven grass, and there has been no sighting of a harvest mouse in Ealing since 1979.

Veterinarian Dr McCormack said: “We’re seeing biodiversity loss all over the planet and some of it is to do with direct human effects.

“Our thinking on harvest mice is that they were once here and they’re not here now because of what we’ve done to our green spaces.

“The council and landowners are managing the land in a much more nature-friendly way now and we’ve got the suitable habitat back that harvest mice once enjoyed.

“Let’s put them back into the ecosystem and see the benefit of enriching it with something that was there before.

“When there’s a missing link in the ecosystem, there’s a lot of other effects that we don’t even notice.

“One of the benefits we will see is a greater diversity and number of birds of prey.”

Ealing Times: Two harvest mice ready for rewilding - Credit James MortonTwo harvest mice ready for rewilding - Credit James Morton

The reintroduction of the UK’s smallest rodent will be staggered in line with the Department for Environment, Food and Rural Affairs’s guidance.

The new population will be topped up with another 150 mice from a different bloodline in September and 150 more next spring. 

The team scoped out five suitable sites for the harvest mice including Smith’s Farm, Marnham Fields and Paradise Fields. 

They will monitor the success of the project by checking the population growth over time with nest surveys and live trappings surveys for small mammals. 

Harvest mice typically have two or three litters a year with around six young in a litter so, if all goes to plan, McCormack hopes Ealing will have a sustained population in ten months.  

The project has received a positive reaction from the Ealing community, with over £2,500 raised in two days for a fundraiser where people could sponsor a mouse for £10.

Dr McCormack said: “The overwhelming response has been that people are delighted and they think it’s fantastic to restore nature and bring back the lost species.

“We’re confident we’ve followed Natural England’s guidance and that this is a responsible and justifiable reintroduction programme.” 

Alongside its harvest mice programme, EWG has been focusing on its ‘Help an Ealing Owl’ project which has involved changing grassland management to encourage biodiverse habitat and putting up owl nest boxes across the borough.  

Featured image credit: James Morton