Threatened mice species released in national park

North York Moors National Park Authority Harvest miceNorth York Moors National Park Authority
The harvest mice are on the Red List of British Mammals and classified as “Near Threatened”

More than 300 harvest mice have been released at a national park as part of a project to re-establish a local breeding population.

The scheme has been led by Steve Mills and Hilary Koll, who live in Hawsker, near Whitby, and has been supported with a £4,200 grant from the government.

They bought a pasture field in the North York Moors National Park about five years ago and noticed a grass growing in the field was favoured by harvest mice.

Once a widespread species in the UK, harvest mice are now classified as Near Threatened and are on the Red List of British Mammals.

The creatures, which weigh around the same as a two-pence piece, are targeted by predators such as cats, owls, and crows.

Ms Koll and Mr Mills had planted trees, built ponds in the field they bought and watched as a habitat full of birds, butterflies and bees slowly developed.

"In different patches of the field, we noticed a certain type of grass, cocksfoot, started to dominate," Ms Koll said.

"In researching this grass, it turned out to be the species most favoured by harvest mice, and so there our journey began.”

North York Moors National Park Authority Hawsker resident Hilary Koll holding a box of the mice in a fieldNorth York Moors National Park Authority
Hawsker resident Hilary Koll has been learning about how to reintroduce the mice into the national park

They also need to live in environments that have dense vegetation, such as long grass and reeds, to help build their distinctive woven nests.

Mr Mills and Mrs Koll also worked with Whitby Naturalists’ Club and the Yorkshire Rewilding Network, and Derek Gow Consultancy, who are experts in UK small mammals, to help ensure they created the right environment for the mice.

The scheme received funding from the Department for Environment, Food and Rural Affairs' Farming in Protected Landscapes scheme.

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