Their release, made possible by a large private donation, will reinforce what is one of the few harvest mouse colonies north of the River Tyne.

In August, another 200 mice will be freed on the 185-hectare reserve, which is a haven for birds and other mammals, and, which it is hoped, will prove a successful breeding ground for the cute animals.

In 2004, Newcastle University PhD student Wendy Fall actively bred 240 harvest mice with the help of volunteers, schools and community groups.  They were released on the East Chevington site as the extensive reed beds provided a suitable habitat for the mice, which build distinctive circular grass nests on tall plants 3ft from the ground.

In the following months, surveys and searches didn’t show any signs of mice or nests, which led conservationists to think the reintroduction, may not have been successful.

Fast forward to 2019 and Wendy took a call from Northumberland Wildlife Trust’s Catch My Drift project team with news that volunteers had found sets of two nests on two separate locations on the reserve - built by descendants from the originally released mice.

Sophie Webster is project manager of the Catch My Drift venture at East Chevington, a three year initiative backed by £418,000 from National Lottery players, via The National Lottery Heritage Fund, to improve the reserve’s habitats, species numbers and upgrade access to the Druridge Bay site, she said: “To find the nests was really exciting for everybody as it’s such a big area to search and we didn’t think we’d ever find any.

“When we knew that the harvest mice were there with the discovery of the nests, we decided on a captive breeding programme and new releases to boost their numbers and increase their genetic diversity.

“The aim of the Catch My Drift project is to make the reserve a stronghold in Northumberland for the harvest mouse again.”

Although part of the wider Catch My Drift project, the release itself has been funded by a generous private donation.