Barn Owls

Barn Owls
July 27, 2011 Adrian Walters

For a number of years the Sudbury Common Lands Charity has had two owl boxes set up in quiet locations. These boxes have been used every year as nest sites by either Tawny owls (Strix aluco), the birds that make the familiar ‘hoo-hoo-hoo’ call, or by Stock Doves (Columba oenas). Both are welcome but the boxes were, in fact, erected to attract the Barn Owl (Tyto alba) which in Suffolk is relatively uncommon. In recent years, however, numbers have increased thanks to the efforts of the Suffolk Wildlife Trust in encouraging interested landowners to erect nest boxes.

Fifty years ago barn owls were not an infrequent sight in Suffolk but with changes in agricultural practices and the loss of ancient trees with suitable nesting holes, the barn owl population became confined mainly to the north-east of the county.

Although grasslands in Suffolk are very scarce, arable fields now commonly have rough margins of long grassland and it is here that populations of voles can live and breed. The Charity’s lands are all cattle grazing lands adjacent to the river Stour and some of these pastures are managed as long grassland during the nesting season. Voles are the main food of the barn owl and large numbers are required to support a pair and their brood.

It was extremely exciting to see a barn owl fly from one of the Sudbury Common Lands Charity owl boxes when inspecting for nesting birds in mid-May. There were three very young chicks inside. Clearly the vole population on the grazing lands was sufficient for all the chicks to survive (see summer gallery). Checking, measuring and leg-ringing of the chicks was arranged by the Dedham Vale & Stour Valley Countryside Project. Barn owl recording work goes on throughout the county so that each year the exact number of reared chicks is known. The box scheme has proved a great success and hopefully barn owls will return to use at least one of the charity’s boxes in future years.