Barn Owls

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Where impacts on barn owls are considered likely (for example renovation to a barn known to house barn owls, or felling of trees large enough to be capable of housing a barn owl) it will be necessary to conduct a barn owl survey. As barn owls have been found nesting all year round, these surveys can be conduct at any time of year. There are several signs to look out for which could be indicative of barn owl presence. More information on the things I look for at the bottom of this page!

The barn owl (Tyto alba) is one of the most distinctive birds of prey in the world, and also one of the most widely distributed, being found across Europe, Africa, Arabia, India and Asia.

Barn owls tend towards open countryside such as farmland and meadows where it can fly silently and unobstructed, listening out for voles and mice which make up the majority of its diet. They are nocturnal, relying on their incredibly acute sense of hearing to detect their prey. Both their ears are hidden underneath feathers, they are different sizes and are not symmetrically placed on the side of the head. The feathers covering the face act like funnels, directing sound towards the ears, allowing the owl to hear in exquisite detail. It is said that a barn owl can hear a mouse’s heart beating up to 30ft away, so it is easy to imagine how loud a mouse running is across a field.

In an RSPB poll, barn owls were voted the most popular farmland bird in Britain, and the most popular British bird, second only to the robin. Sadly though, their numbers have been declining. This is likely to be a result of several factors including low food availability due to intensive farming, road mortality, loss of traditional roost/nest sites and effects of secondary poisoning by rodenticides.

As with all birds, the Wildlife and Countryside Act 1981 protects the eggs and nests of the barn owl. They are listed under Schedule 1 of the amended version of the Act, which makes it illegal to:

• Kill, injure or take (catch/capture or have in one’s possession) a barn owl
• Take, damage or destroy the nest of a barn owl, whilst the nest is in use or being built
• Take or destroy a barn owl egg
• Have in one’s possession or control a wild barn owl (dead or alive) or egg
• Intentionally or recklessly disturb any dependent young of wild barn owls

Pellets are regurgitated by the owl to get rid of the indigestible bits of their dinner such as bones and fur. The pellets are distinguishable from those of other species when they are fresh, as they are the only known pellet that is black when fresh, slowly turning grey over time. Other species such as kestrel, little owl and buzzard all produce grey pellets.

This is a slightly harder sign to distinguish, as barn owl droppings are white, watery ‘splashes’ (if they land on the floor) or ‘streaks’ sometimes with small black parts. Usually, they will be found under suitable roosting or perching places, such as branches and beams. As they can be hard to distinguish from other large birds, they cannot be used solely to determine barn owl presence and will often be found with other signs.

Needless to say, finding barn owl feathers is indicative that a barn owl was once there. With a trained eye it is possible to determine whether they are male or female, and whether they are adult or nestling feathers.

Where a barn owl only roosts, the pellets will have time to age and dry without being disturbed, and will still look like pellets. In contrast, in a nest, the pellets will be continually walked on whilst they are still soft, resulting in a compacted layer that will solidify into a mass without many individually distinguishable pellets. Along with the pellets, there is likely to be nesting materials – grasses and soft vegetation, perhaps even some un-eaten small mammals and insects that are left there as a cache for when hunting becomes harder in winter months, and occasionally the odd unviable egg.