Barn Owl (Tyto alba)
There are few sights on the Weald Moors guaranteed to stir the senses more than the spectral presence of a Barn Owl quartering the rough margins of a strine, ditch or field edge at dusk. Until recently, this bird really was something of a moorland ghost but a concerted effort has turned it into one of the area’s conservation success stories.
ID: with a white, heart-shaped facial disk, golden, buff-coloured plumage and long wings (which are much bigger than its body) the Barn Owl is surely among the most recognisable of our native birds. Within earshot alone, its unearthly shrieking call is a unique aural signpost and quite unlike that of the Tawny and Little Owl also present on the moorlands.
In the Field: this raptor is the very definition of a farmland specialist but, when it comes to its dietary needs, one with a very specific set of requirements. Barn Owls, you see, are a bird of vole-rich country: a.k.a permanent, ungrazed grassland with plenty of tussocks and a deep litter layer of fallen stems and leaves at the base. These areas, which appear browner than typical pasture land, provide Field Voles with the right conditions to establish thriving colonies — something that does not happen where regular grazing and mowing occurs.
In Shropshire, voles form around 70% of a typical Barn Owl diet and research has shown that where their density is highest, owls tend to breed earlier and lay more eggs, with a greater number of young surviving to adulthood. Sadly, rough grassland is not as common as it once was and its loss is thought by experts to be a primary reason behind their decline. However, Barn Owls also hunt along the grassy margins of arable fields, streams and ditches, which, when left undisturbed to grow tall and wide, can also harbour large numbers of small mammals. Consequently, this is now an increasingly important habitat feature for many local owl populations.
Shropshire Barn Owl numbers appear to have been in long-term decline since at least the mid-1800s but have suffered a steep descent in the Post-War period, with the number of breeding pairs declining by at least half. While loss of prey-rich habitat is a major problem, traffic fatalities on main roads are another key concern — In Shropshire, the A5 alone has accounted for over a third of all Barn Owl deaths in the new century. Autumn and winter are especially dangerous times for juvenile birds and adults alike, finding both on the move; the former (which have practically no homing instinct) dispersing to find new territories and the latter expanding their winter hunting ranges.
On the Weald Moors: another major problem facing Barn Owls is a vast reduction in suitable farm buildings for roosting and nesting, which they will often use over the course of their entire lives. While they also nest in the hollows of mature trees, in Shropshire at least, a nest box appears to be a more enticing option. In the last decade, the Shropshire Barn Owl Group has created a network of over thirty boxes, producing an increasing number of fledglings across eleven sites on the Weald Moors.
Barn Owl territories are large and thinly distributed and the best time to see them on the moorlands is during the breeding season, when they are at their most active. Chicks rearing generally occurs between June and July, so if you witness a bird carrying prey in its talons at this time it will almost certainly be going to feed a young mouth (which will require at least four small mammals a night!). While there are still pockets of good grassland for Barn Owls scattered across the Weald Moors, rich grassy areas are probably more common around riverbanks, ditches and fence lines (which are also used for pole hunting in winter). However, woodland edges and young plantations can also provide good conditions where the ground cover is right.