Written by Jayna Connelly, Science Communicator
Barn owls are one of the UK’s most iconic farmland birds and an easy way to help support these beautiful creatures populations is by putting up a barn owl nest box. But this is only the first step. Regular cleaning is essential to keep the boxes safe, hygienic and optimise the chances of them been used successfully year-on-year.
While barn owls require a layer of debris at the bottom on their nest box to lay their eggs in, it is essential we maintain a clear distance between the access hole and the floor of the nestbox to limit the risk of owl chicks falling out. Cleaning the box will help limit heavy infestations of fleas, mites and lice as well as giving you a chance to check of mould, rot and ensure any drainage holes are clear.
The legalities around disturbing the nest of different species is a bit of a minefield so it is generally best to leave the box alone if you find any eggs in there. Some species like Jackdaws may use the box and these will fill it with sticks very quickly so it is important to clear it during the right time of year to limit disturbance. Generally between November and February is the best time as while some species are recorded to nest in all months of the year, this is the least likely.
When cleaning out the nest box, time of day is also important. Late afternoon/early evening is generally commended just in case you do flush anything from the box or area so that the bird is not stuck out in daylight. Similarly, picking a cool, dry day will help limit the risk any disturbed animals are in.
Barn owls tend to create quite a compacted layer of debris so a screwdriver or chisel may be necessary to loosen the contents of the box enough to remove it. Leave a thin layer at the bottom as barn owls do not collect additional materials to create their nest and rely on a layer of pellets to lay the eggs onto.