James Atkinson
Why Barn Owls Belong on a Cumbrian Farm
There are few sights more magical than a barn owl drifting over a Cumbrian meadow at dusk. With its white underparts and silent flight, it is a bird that feels almost otherworldly. Yet it is also a practical ally for any farmer or smallholder. A single barn owl family can eat thousands of voles, mice and shrews in a year, helping to keep rodent numbers in check around buildings, feed stores and pasture. Encouraging them onto your land is not just good for wildlife; it is good for the farm. The key is to provide two things: plenty of rough grass for their prey, and safe, undisturbed places to nest. Get those right, and you give these beautiful birds a genuine chance.
Creating a Vole Larder: Rough Grass and Margins
Barn owls are specialists. They hunt almost entirely by sound, quartering low over the ground with their ears tuned to the rustle of small mammals. Their favourite prey is the field vole, and voles need cover. Short, tightly grazed pasture is a desert for them. What you want is a mosaic of tussocky grass, ideally 20–30 cm tall, with a thatch of dead stems at the base. Field margins, awkward corners, wet rushy patches and unimproved pastures are perfect.
On a smallholding, you can create this without losing much land. Aim for margins of 3 to 6 metres along hedgerows and fences. Cut them on a rotation of two or three years, and never all in one go. Leave the cuttings in place for a few days so seed drops, then remove them to avoid smothering. Avoid fertiliser, slurry or herbicide on these strips. If you have a rushy field, don't drain it all—leave a damp hollow. Voles thrive where grass is thick and soil is soft. A rough grass margin of just half a hectare can support enough voles to feed a breeding pair.
- Leave tussocks uncut through winter.
- Avoid topping between March and September.
- Create shallow scrapes or wet corners for damp-loving voles.
- Plant native hedgerows with a thick base—they act as corridors.
Nest Boxes: Siting and Design
Barn owls need a dark, quiet cavity. Traditional barns and old trees are increasingly rare, so a well-placed nest box can make all the difference. Build or buy a box made from 18 mm untreated plywood or exterior-grade timber. A good size is roughly 700 mm high, 500 mm wide and 500 mm deep, with an entrance tunnel to keep out predators. The entrance hole should be about 100 mm across, or a vertical slot 130 mm wide. Line the floor with a few centimetres of wood shavings or dry soil.
Site the box at least 3 metres above ground, on a pole or the gable end of a building. Face the entrance away from prevailing wind, usually between north-east and south-east. Crucially, keep it away from roads. Barn owls hunt low and often cross roads at dusk; road mortality is a major killer. Aim for at least 500 metres from a motorway or dual carriageway, and 200 metres from a fast B-road. Avoid busy farmyards with constant machinery. A quiet corner of a rough grass field, near a hedgerow, is ideal.
Rodenticides: A Hidden Danger
This is the single most important thing you can do for barn owls: avoid using rodenticides. Second-generation anticoagulant rodenticides (SGARs) accumulate in the liver of rats and mice. When an owl eats a poisoned rodent, it receives a sub-lethal or lethal dose. Affected owls become lethargic, bleed internally, and often die. Even sub-lethal doses reduce hunting success and breeding output.
If you have a rat problem, use traps, secure bait stations, and clear up food sources. Never broadcast poison or leave it in open trays. If you must use rodenticide, use it only in and around buildings, not in fields or hedgerows, and never where owls are known to hunt. Talk to your vet or a qualified pest controller about the safest approach. Remember that a healthy barn owl population is itself the best rodent control you can have.
Patience, Monitoring, and Coexistence
Don't expect owls to move in overnight. It can take a year or more for a box to be found, especially if the local population is low. Look for signs: white splashes of droppings below a perch, or dark, shiny pellets (regurgitated fur and bone) on the floor. Listen for the eerie, drawn-out screech of a young owl in late summer. If you are lucky enough to have a breeding pair, keep disturbance to a minimum. Do not open the box between March and September. Keep dogs and children away from the base of the nest tree or pole. Farm work nearby is usually fine, but avoid noisy machinery right beside the box at dawn and dusk.
With a little rough grass, a safe box, and a poison-free landscape, you can tip the odds in favour of these remarkable birds. It is a small change to your farm that pays back in beauty, natural pest control, and the quiet satisfaction of knowing you have helped a species that has declined so much across the UK. Cumbria's smallholders and farmers have a real opportunity to make a difference—one tussocky margin at a time.
