Summer 2002

The Barn Owl in South-West Lancashire

Article by Tony Duckles, Sefton Coastal and Countryside Service

The Barn Owl (Tyto a. alba) is one of Britain's elegant hunters. It's soft feathers make it's fight almost silent. Barn Owls prefer to hunt in an open habitat including rough grassland, field margins, hedgerows, woodland edge, drainage ditches and farmyards. They usually hunt by flying slowly back and forth, a few metres above the ground, looking and listening for their prey. If suitable perches such as fence posts are available, the owls may save energy by hunting from these. Their diet consists mainly of small mammals, particularly field voles, common shrews and wood mice. They often swallow their food whole and the indigestible parts, the bones and fur, are regurgitated in the form of a pellet. Analyzing Barn Owl pellets can tell you exactly what small mammals the owls have eaten.

The Barn Owls suffered a large decline in the mid-part of the 1900's due to the changes in agricultural practices, loss of habitat and loss of suitable breeding sites. Since 1968 members of the South West Lancashire Ringing Group have been erecting nest boxes in this part of the county for these birds. Ringing of nestlings and occasional adults has taken place on an annual basis. At present over 1000 young Barn Owls have been ringed. However, only about one in four young Barn Owls survive their first year to become breeding adults. The oldest living ringed wild Barn Owl in Britain lived for 13 years 4 months and 11 days.

In the early years of the nest box scheme only 20 pairs were using our boxes, but since then there has been a gradual increase in this area and nowadays 40 to 50 pairs breed in this region. The success of nest boxes has been amazing and from the ringing we have been able to monitor movements from the area. Birds will be seen to have moved from this area as far as Hest Bank (North Lancashire), Bedfordshire, Essex, Gloucestershire and Staffordshire.

In recent years conservation bodies, e.g. RSPB, Lancashire Wildlife Trust, The Hawk and Owl Trust, English Nature and the Environment Agency (Conservation section) have become involved in this species conservation. It remains a pity that the latter's mowing regimes in our area continue to be carried out in the summer months, at a time when many rodents are present on moss land brooks, eg Downholland Brook.

Although in this area Barn Owls are increasing, this is not the case everywhere in the country. Post-war intensive farming, the removal of hedgerows, the increased usage of pesticides and herbicides all had their impact on the population. Furthermore, the use of rodenticides; especially second generation rodenticides, to control the levels of agricultural pests have been proved to affect the Barn Owl population by entering the food chain. On the plus side has been the introduction of the Set-aside scheme, a practice of taking agricultural land out of production. This along with the replanting of hedgerows is encouraging safe havens for rodents and good hunting areas for predators.

The benefit of nest boxes is not just for breeding but for the provision of safe refuges for birds in winter. On checking nest boxes in winter has produced evidence that the Barn Owl will store prey. A cache of seven Short-tailed Field Voles was found in one box. Regular pellet analysis carried out by the group, Sefton Coast and Countryside staff, through Natterjack Club events, and on a nationwide basis reflect any changes in the diet of the species. It is interesting to record both seasonal and regional variation in the prey taken from pellet analysis.

Finally, thanks to closer liaison with local authorities, planning applications for barn conversions or demolition are subject to more stringent scrutiny, i.e. Barn Owl and Bat surveys are required. In this part of the country the future is looking good for the Barn Owl.