The harvest mouse is Britain's smallest rodent and has declined dramatically due to changes in cereal farming, with welfare implications for individual mice during intensive harvesting.
Individual harvest mice face welfare threats from mechanical harvesting that kills nest-bound young and injures or kills slower adults unable to escape combine harvesters. The transition to winter-sown cereals, which are harvested when young from summer breeding are present, has been particularly damaging. Pesticide use reduces insect prey availability affecting nutritional welfare. Field margin management that retains tall grass and tussocky vegetation provides refugia that protect individuals during harvest operations. Conservation headlands and beetle banks benefit harvest mice alongside many other farmland species.