The diet of the Barn Owl in Shropshire
The Barn Owl is an avid hunter of small mammals. Prompted by the lack of specific data on the diet of Barn Owls in Shropshire and the need to inform habitat management recommendations the Shropshire Barn Owl Group has been collecting and analysing samples of pellets from nest sites and roosting sites across Shropshire since 2002.
Items are identified mainly from the jaws of the prey found in the pellets. We have so far identified 1458 separate prey items from 522 pellets collected from 69 different sites.
The analysis clearly shows that the main prey item of the Barn Owl in Shropshire is the Field Vole, comprising 71% of the prey items. Secondary prey include Wood Mouse (12%), Common Shrew (9%) and Bank Vole (5%). Pygmy Shrew, House Mouse, Brown Rat and birds each account for less than one per cent of the items consumed.
It is estimated that the Barn Owl's food requirements amount to around 75g per day or 23% of a bird's body weight. This equates to three average sized Field Voles per day, 4000 a year to feed a pair and their young.
Field Voles require permanent, rough tussocky grassland which is largely undisturbed. Grassland of this type on farmland is now often confined to field margins - arable headlands, hedgerows, fence lines, banks, ditches and riverbanks. The conservation of these habitats is paramount if the breeding status of the Barn Owl in Shropshire is to improve.
To encourage Field Voles:
- Increase the amount of permanent rough grassland
- Ensure a litter-layer no less than 7cm deep is retained
- Maximise the diversity of grass species. Some favoured grasses in the diet of Field Voles are Yorkshire Fog, Meadow Grass and Sweet Vernal Grass
- Avoid mowing - this will destroy the litter layer and erase Field Voles