The ghostly silhouette of a barn owl, seen silently floating over a meadow, marsh or field margin is a view of Suffolk’s landscape that many people treasure. But with the loss of habitat and nesting opportunities the breeding population had fallen below 100 breeding pairs in the county by 2005.
Working alongside the Suffolk Ornithologists Group, Suffolk Wildlife Trust has been involved with a countywide initiative to install barn owl nest boxes. This has helped restore the number of barn owls to levels not seen since the 1930s. The following information and contacts are designed to help you understand and manage barn owl habitat to ensure the continued success of this evocative bird.
From around 1945 barn owl numbers across the UK plummeted, with populations falling by almost 70% over 50-60 years. By the turn of the century, there were thought to be only 100-125 pairs in the county, mainly in north east Suffolk. It’s believed the dramatic decline of what was considered to be a common and well-distributed owl was caused by a combination of habitat loss and a shortage of viable nest sites.
With the outbreak of war came the intensification of farming techniques. Changes to the management of field margins, watercourses, hedgerows, woodland edges and even roadside verges meant that rank grassland - the owls’ favoured hunting site for voles, mice and shrews – became fragmented. It is estimated that since 1939 a hefty 96% of Suffolk's unimproved grassland has been lost.
A reduction in farmyard foraging by rodents due to improvements in the methods of handling grain and the lethal effects of organochlorine pesticides also took their toll. As food sources dwindled and hunting grounds shrunk, traditional nesting sites vanished as the number of hollow trees available were reduced by Dutch elm disease and other causes and barns were sealed up, replaced with modern structures or converted into dwellings.
The construction of major new road networks also hit owls hard. Not only did new highways fragment habitat, but faster traffic left owls flying at hunting height unable to avoid collisions.
Barn owl is predominately sedentary and site faithful – the same pair will use the same location year after year. With soft unwater-proofed feathers, which quickly become saturated in the rain, barn owl need sheltered nest sites, and roost sites for the male, to breed successfully. As one of the UK’s driest counties, Suffolk is a natural stronghold.
Although the owls have been severely affected by the loss of mature trees and agricultural buildings, fortunately barn owls take readily to nest boxes and since 2006, Suffolk Wildlife Trust has helped transform the fortunes of barn owl in Suffolk, through an intensive nest box programme.
Supported by a network of trained volunteers, the Trust has monitored more than 1,500 barn owl boxes and barn owl have spread from their stronghold in north east Suffolk into central and western Suffolk. As a result barn owls are now seen in places where they have been missing for generations.
Roads are by far the largest cause of barn owl mortality with accidents on minor roads killing young barn owls after they have fledged and major roads killing adult birds that survived fledging and dispersal. Whilst this can be partially remedied by growing tall hedges as a boundary between busy roads and barn owl hunting habitat, it is difficult to completely block off roads to barn owls because of the practicalities of having gaps in the hedge such as gateways where barn owls will naturally swoop low through.