Image: Nigel Blake
The barn owl is primarily a farmland bird, hunting for small mammals over rough grassland and along field edges.
The barn owl population decline is largely a result of reduced food supply, with less rough grassland available for hunting. The loss of old barns and increased road deaths are also significant in many areas. Barn owls can be encouraged by providing prey-rich rough grassland and artificial nest sites.
Nest and roost sites
They are traditionally associated with old barns and hollow trees but take readily to nestboxes placed in modern farm buildings, trees, or spaces provided in barn conversions.
Food and habitat
They primarily eat voles but also regularly include mice, shrews and rats in their diet. Their prey occurs at highest densities in rough grassland – tall, tussocky grass with a thick litter layer. Grass that's too short, lacks a litter layer, or is overgrown with scrub is far less suitable for barn owls.
Protect and maintain existing nest sites in buildings or tree holes
Existing nest sites can be supplemented with nestboxes of various types
It is a good idea to erect boxes in pairs – within 500 m of each other – at a density of about one ‘boxpair’ per km sq
With many barn owls killed each year by cars, it is strongly advised not to mount a box within 1 km of a major road.
A pair generally hunts within 2km of the nest site during the breeding season, and requires rough grassland in the form of blocks and/or wide strips along field margins, woodland edges or watercourses. The ideal amount of rough grassland to aim for is 31-47 ha in pastoral areas, 14-21 ha in arable areas or 17-26 ha in mixed farming areas
Rough grass strips should be at least 2 m wide (ideally 6 m) and it is preferable for blocks of rough grassland to be linked by hedges or grass strips. Livestock should be prevented from grazing the grass strips
Rough grassland can be established using a grass-seed mix that includes tall, tussock-forming species (eg cocksfoot and timothy) along with shorter, softer grasses (eg Yorkshire fog, fescue and bent species)
During the first year, new grass should be left to grow tall and collapse in the autumn thus forming the litter layer above which the second season’s growth will appear
Following establishment, areas should be topped, or lightly grazed every second or third year
Cutting should be undertaken in the autumn with the cutting blades set at 10 cm (4 in) or higher
Where possible, cut rotationally within the landscape (eg cut each ditch-side in alternate years)
Take care to protect barn owls from secondary poisoning during rodent control and be aware that bait-covering does not reduce the risk. Contact the Barn Owl Trust or visit their website for detailed information.
Last updated: 3 December 2008
What barn owls need and how they can be encouraged to your farmland.