Harvest mice are Britain's smallest rodent and face welfare pressures from intensive cereal production, combine harvesting trauma and loss of winter tussock grass habitat.
Harvest mice in standing cereal crops are directly killed or traumatised by combine harvesting over vast areas simultaneously. Winter survival depends on dense tussock grass or bramble where mice build overwintering nests — loss of this habitat causes cold-weather mortality. The species is not adequately surveyed to quantify welfare impact, meaning the aggregate burden of combine harvesting on harvest mouse populations is unknown but likely very large in arable landscapes.