Barn owls at Heligan

Barn owls can be seen throughout the year at Heligan; at first hand during the winter months as they hunt near Horsemoor Hide Wildlife Centre and live, via cameras, in their roost site and the nest box. The old farm buildings provide a warm and dry roost site throughout the winter months, tussocky grass and field margins help to support small mammal populations and the provision of artificial nest boxes has created a safe haven in the nesting season. The best time to catch a glimpse of a barn owl is at dusk and dawn when they can be seen quartering fields and hedgerows. The south west of Britain has remained a stronghold for barn owls even during times of greatest decline. This part of mid-Cornwall is no exception with its hedgerows, grassy margins and scrub areas all providing excellent hunting grounds. We’ve been filming barn owls here at Heligan for 6 years and apart from 2006 (a bad year country wide) we’ve had broods every year. So far 2007 looks to be good with 7 chicks hatching from 7 eggs.  

Recognition and Habitat

The barn owl is a large bird (33-35 cm tall) with long broad wings that allow excellent manoeuvrability at slow speeds just above the ground. Almost totally white from beneath, head and back golden buff or a rich ochre in colour with an intricate pattern of flecks and markings. Male birds are generally paler in colour than females. Both sexes have a heart shaped face with dark eyes. Resident all year round in Britain. Call is a chilling screech; a long drawn out sound increasing in volume and then finishing abruptly. Other calls include chirrups, squeaks, snores, hisses and clicks. The infamous silent flight of the barn owl is achieved via comb-like extensions on the leading primary feathers. These moderate the passage of air over the wing surface therefore minimising turbulence and noise during flight.

Predators and Prey

Natural predation of barn owls is rare. Most death occurs in the winter months due to starvation of first year birds. Other causes of mortality include road death and drowning. Barn owls are crepuscular meaning that they are active before dawn and at twilight. This corresponds with the times of greatest activity of voles, shrews and mice. Their flight is purposeful; barn owls are creatures of habit, preferring to hunt a well-known territory where their success rate is guaranteed. They will repeatedly fly back and forth over an area, a technique known as ‘quartering’. They glide a few feet above the ground, sometimes stalling, twisting and cartwheeling until they locate a target. They will then hover before plunging headfirst for the prey. In addition to aerial hunting they also adopt a ‘perch and wait’ technique where the owl will use a post, tree stump or fence to wait for prey to pass underneath. This method is often seen during the winter time as it more energy efficient than aerial hunting.

Life cycle

The breeding season begins in February when existing pairs re-affirm their bonds and new birds find a mate.  Courtship involves aerial displays by the male and the selection of a nest site, which may be an artificial box, tree or open building.   Eventually he will start to bring food to the nest site and deposit a store that is thought to trigger copulation. The increase in prey stored at the nest site also triggers egg laying by which point the female is fed almost entirely by the male. On average 5 eggs are laid at 2 to 3 day intervals that hatch after 30 to 31 days of incubation performed only by the female.  Chicks will fledge after 9 weeks and stay with the parents for tuition for a further few weeks.

Legal and conservation status

The barn owl is on Schedule 1 of the Wildlife and Countryside Act, 1981 and The Wildlife (Northern Ireland) Order, 1985.  Offences against barn owls can result in a fine of up to £5,000 or a custodial sentence. It is also illegal to release barn owls into the wild in Britain without a licence.

Did you know?

Tyto alba is the only barn owl species in the UK although 36 other species exist worldwide.  Tyto is a Greek word meaning ‘a night owl’ and the species name alba is a Latin word meaning white. ‘Old hushwing’ is a traditional name for the barn owl.