Haunted by a Silent Spirit.

Barn owls are an evocative member of our local wildlife. 

The advancing sun, bright with a warm embrace, cuts the morning sky, sculpturing a landscape embroidered with farmsteads, copse, meadows and rolling downs. The grass barely moves, buoyant underfoot, with lays of deep thatch barely touched by February's frost. A cloud passes silently overhead, beyond vision, scentless, without a breath of air. The need to feed remains strong, many have not survived the cold winter. A well used path presents itself before you, which many have used before, running through the meadow like a road. Again the cloud passes, this time turning overhead against the wind, beyond vision, beyond scent, silent, you freeze . . . . . . . . . . . darkness consumes you.

 Field voles are a key prey item but not just for barn owls, but for a whole host of predatory species. An overlooked but key element to many food webs. 

If field voles had autobiographies this would perhaps be a rather fitting bit of poetic justice for many of them. The perspective of the field vole completely unaware of the barn owl silently quartering the meadow reflects just how superb these birds are at hunting small mammals. With the regular cold weather all but killing off many active invertebrates or making them shelter and keeping amphibians and reptiles tucked away, I have been lucky enough to have spent some time watching the local barn owls. The pan list has slowed down as a result of work and the cold snap so what better way of spending your time than watching these haunting birds. A species which is iconic with Yorkshires agricultural lowlands.

Very fresh barn owl pellets, before collection on the floor of an old farm building, photographed whilst looking for bats. 

Fortunately barn owls can be used almost inadvertently as a small mammal surveyor, their largely sedentary nature and use of regular roosts means that barn owl pellets are easily found and can reveal a lot about the small mammals which live in a given locality or habitat. Although we cannot include dead animals in the YETI list, it does provide an idea of what is in an area and if it's worth having a go at small mammal trapping, which we may certainly undertake to tick off a few species. 

Barn owl pellets are distinctive and instantly recognisable in comparison with other British birds of prey. Typically a blunt ended cylindrical, either round or slightly sausage shaped pellet, which is black when fresh fading to a dark grey, often covered in a thick black crust. They are usually compact and are found at roost sites. Barn owls usually roost in buildings, holes between hay bales, in nest boxes, bird hides and trees which offer sufficient shelter. It is however best to avoid going near to roost sites unless you know the bird is not present, to avoid unnecessary disturbance.

Short-eared owl pellet. A distinctively different pellet to that of the barn owl, but often found within rough grassland, near ground roosts in tussocks or low vegetation. 

Whilst out and about looking for barn owl pellets and looking for species to add to the YETI challenge I have also uncovered short-eared owl pellet and common buzzard pellet. Whilst taking the recent batch of barn owl pellets apart I have found woodmouse, field-vole and common shrew. These are all quite typical barn owl prey and make up the preponderance of pellet contents, with occasional pygmy shrews. It's interesting that barn owls readily consume shrews which are generally considered distasteful by most avian and mammalian predators due to the presence of flank scent glands, this is due to barn owls having rather poor taste or sense of smell. These scent glands consist of an area of skin that is thickened by the presence of a large number of sebaceous an sweat glands. Studies show that roughly one third of the diet consists of field vole, almost a quarter of common shrew and the rest a mixture of woodmouse, pygmy shrew, bank vole with occasional brown rat, water shrew, harvest mouse and birds. In respect to the latter I have found starling remains in nest boxes and chaffinch skulls in pellets, there are reports of finding snipe skulls (with beak) in pellets. Barn owls rarely take birds larger than blackbirds, unlike tawny owls. The reduced number of bank voles in the diet in comparison to how common they are is reflective of the species preference for more wooded habitats avoided by barn owls.  

Common buzzard pellet, often found below favoured roost locations in trees. 

Woodmouse skull on the left showing the rounded cluster like teeth typical of mice and field vole on the right showing the zig-zag teeth typical of voles. Both taken from the same pellet. 

Common shrew skull and lower jaw, a species which barn owls appear particularly fond and is usually the secondary key prey item. 

Snowdrops are now showing well across the region.