Barn Owl's are an owl species of open countryside, favouring areas of farmland and rough grassland to hunt their prey species of predominantly voles, mice and shrews.
When considering habitat creation, restoration or management, the ultimate aim to help support Barn Owl populations, is to increase suitable habitat for their prey.
Pasture is grazed grassland which is usually intensively grazed, with short grass and no cover for small mammals to hide, feed or breed. Some long and temporary grassland cover can also be unsuitable, with a lack of variety of plant species, and will be cut too regularly to provide the right conditions for small mammals.
Arable fields can hold good numbers of prey, but some, such as Oil Seed Rape may be quite bare during some of the year with no food for small mammals, and therefore not a suitable hunting ground for Barn Owls. Similarly, Winter Barley doesn't provide a stubble field in the winter so will not support sufficient small mammal numbers throughout the year. Winter stubble fields provide a vital food resource for many farmland birds during the hungry gap through December to March, and also provide grain for small mammals, allowing hunting opportunities for Barn Owls.
Rough grassland however, is the optimum habitat, providing small mammals with ample foraging and nesting opportunities, making them incredibly important hunting grounds for Barn Owls all year round, as well as providing a variety of wild flowers as an important nectar source for many invertebrates.
Common Mice, Field Voles and Shrews are all found in rough grassland and prey from these areas form a large proportion of a Barn Owl's diet. To create areas of rough grassland, grass needs to be encouraged to create a thick, dense litter layer, to provide cover and breeding habitat for small mammals. The litter layer needs to be at least 7 cm deep; this can be achieved by letting summer grass growth die back, without being grazed or cut.
Over time (2 - 3 years) the litter layer will build up, but ongoing management in future years may include some grazing to avoid scrub encroachment or species like Bracken from becoming dominant. After a number of years, grazing with cattle can be introduced from late summer to late winter, or a topper can be used to ensure the litter layer remains, but longer vegetation is taken off.
If large areas of rough grassland cannot be introduced, then field corners or margins are great areas to establish rough grassland habitat.
Rough grassland provides a dense litter layer for small mammals to burrow (C) Barn Owl Trust