Wander deeper

the barn owl’s primary prey species,” he says. “Barn owls have relatively poor eyesight. They rely on hearing to locate field voles and the feathers of their facial disk have evolved to reflect sound towards their asymmetrical ears, which are offset and different sizes to help pinpoint prey as they fly.”

Barn owls are one of the world’s most widely distributed owl species, but in the UK they are at the edge of their range. Softer wing feathers that have evolved for silent flight are easily waterlogged, so they can’t fly when it’s raining, they struggle to hear when it’s windy or hunt when there’s snow covering the ground. Young, inexperienced owls are particularly vulnerable and it is thought that up to 85% of fledglings will perish by the following spring. Road collisions, drowning in cattle troughs and poisoning from rodenticides all contribute to fatalities, but barn owls numbers have recovered from a low in the 1970s and are now thought to number around 10,000 pairs in the UK.

While barn owls can be seen flying slowly over open fields, the shorter, broader wings of a tawny owl are built for manoeuvrability between trees. These perch hunters will wait to drop silently on their prey, mainly small mammals, but also amphibians, insects and even fish.

If we want to see one tonight, we need the same patience, so as night seeps between the trees, we wander deeper into the woods. ▶

the woods.

An owl’s flat face features a circle of feathers that can be adjusted to focus and direct sound into their asymmetrically placed ear cavities.

Most owls are able to fly silently and this is more important for those that hunt at night. The structure of their wing feathers has evolved to deliver the minimum of noise within the hearing range of their prey.

An owl’s retina is packed with rods that function best in low light, rather than cones that are used for colour vision. They have around one million rods per square mm, around five times as many as we do. A layer of tissue behind the retina, called the tapetuim lucidum reflects light within the eye to enhance night vision.

Additional neck bones allow the owl to rotate its neck through 270 degrees, and larger arteries in the vertebrae and neck ensure that blood supply to the brain is not cut off.

“When I bring people out to see owls, I get them to sit with their back against a trunk and listen quietly,” says Ian. “Focus on an area of empty sky through the canopy and you may well see them silhouetted as they fly through the trees.”

Tawny owls reached their peak in Britain in the late Mesolithic era, after glaciers had retreated and woodland returned. Numbers at this time are estimated at around 160,000 pairs. Specialist nocturnal hunters, they have large eyes that account for 3% of their body weight and a retina that is packed with light sensitive rods.

But our ancestors evolved to hunt out here too and our eyesight compares surprisingly well. The structure of a tawny owl’s eye is designed to produce a large, bright image, but their success as hunters relies on a mix of vision, hearing and local knowledge. Our ability to see at night is an ancestral heirloom we’ve largely forgotten: a genetic Picasso hidden in the attic of your DNA. In an era of headtorches, backlit screens and Netflix, we seldom sit quietly outdoors at night and explore what our senses can really do.

As dusk deepens, shapes and textures appear out of the gloom. There’s a whiff of fox in the air, breeze moving through branches and a robin’s alarm call in the distance. Above, the tree canopy arcs like the frame of an ancient yurt, and between the latticed branches, we finally see a shadow flying overhead.

“That’s a tawny owl,” says Ian, leaping up. “Won’t be much else flying around now.”

We follow its flight, feeling our way between the trees. I try to keep my footing on uneven terrain, while tree roots claw at my boots. As Ian hoots we zig-zag, following its response. Suddenly there is a full-blown conversation and I find myself unable to distinguish between Ian and the owl above me.

COUNTRY WALKING

He is convinced this is a male. “Female owls are 25% larger than the males and they’ve been known to attack and kill young owls encroaching on their territory,” he whispers. We hear the hoot and we wait for the contact call – a sharp ke-wick – that might indicate a breeding pair. If he does have a mate, they could lay a typical clutch of two or three eggs in late winter or early spring, that will hatch after a month’s incubation.

Ian calls out again with his near perfect tawny impression and an insistent warning fires back: Roo-weet, roo-weet, roo-weet.

And then we spot it: the broad, stubby outline of an owl flying just metres above us, and I whirl on my heels trying to see where it lands. For our

These are nocturnal hunters that are widespread across Britain but not found in Ireland. The oldest recorded was over 23 years old, but they typically live to around four years old, and will breed in their first year. Young are pushed out of their parents’ territory in autumn but often find their own within just a few kilometres. 

You need the patience of a hunting owl to spot one, so you might want to sit down.

Often seen quartering over open fields, this long-winged owl hunts in flight over lowlands, and populations are most dense in areas of Yorkshire and East Anglia. White underneath and a golden buff on the top, it is instantly recognisable. It is not particularly vocal but the male’s screech can be heard during the breeding season.