Harvest mice are Britain's smallest rodent and build spherical nests woven into cereal stems and tall grass, but have declined significantly due to agricultural intensification and loss of rough grassland.
Harvest mouse welfare is compromised by intensive agricultural management that removes the structural complexity of tall grass and cereal habitats. Mechanical mowing causes direct mortality when nests are destroyed. Winter stubble retention and rough grass margins provide critical habitat that is increasingly provided through agri-environment scheme management.