A bird of copses and well wooded parks and gardens, the tawny owl is the most common owl over much of Britain, although it is not found in Ireland. It is protected, but not an endangered species, and there are approximately 50,000 breeding pairs in the UK. Tawny owls are regularly seen and heard in Fairfield.
Most people will be familiar with the appearance of the tawny owl even if they have never seen one. It is about the size of a wood pigeon and is mottled brown in colour with a round facial disc and dark brown eyes, It has an amazingly flexible neck and can turn its head through 360º so that it can keep its face towards an observer moving around it. It has rounded wings with a span of about 100 cms. There are no tufts on its head. The female is very slightly larger than the male. Like most owls it hunts by night and roosts by day, but during nesting time might hunt in broad daylight. Each bird has a favourite daytime roost in the fork of a tree or on an old squirrel drey, but is often mobbed by smaller birds, which it usually manages to ignore. Underneath the roost is the place to look for the fur-covered pellets containing animal bones and parts of its food it cannot digest and regurgitates.
Tawny Owls mate for life, following breeding in their second year. Their lifespan in the wild is about five years and each pair needs a territory of about 30 acres. It is unlikely that Fairfield will support more than two pairs. Tawny owls readily take to man made breeding boxes and there are two boxes mounted in tall trees in Fairfield, one in the southern shelter belt and one at the Fairfield Park end of West Drive, but they also make use of holes in trees, old magpie nests and squirrel dreys. They do not introduce nesting material of their own.
Re-bonding of the pair begins in October and November when the haunting twit – tawoo calls between the pairs echoes on dark evenings. Mating takes place in early Spring and between two and four round eggs, off white with a few brown spots, are laid in April. The incubation, by the female only, is 25 to 30 days. The young are fed mainly by the male and fly after 30 to 37 days. The chicks sometimes leave the nest before the flight feathers are fully formed, but continue to be fed by the parents outside the nest. This is a very vulnerable time for the young and around 50 per cent of them don’t survive their first year.
The tawny owl diet is mice, voles, young rats, shrews, some small birds, frogs, molluscs, worms and insects. Despite being a night time hunter its eyesight is not exceptional but it has incredible hearing and can turn its ears independently towards the sound of possible prey. Adults have very few natural predators by the time they reach their second year.