Outdoors: Tawny owls set to make presence felt in the months ahead

OVER the next few months as the nights get perceptibly longer, our tawny owls will become increasingly vocal as young birds try to make their mark and form territories. The owls hoot and screech from just after sunset right through to dawn, making it one of the busiest times of year in the owl calendar.

Setting up territory is an energy-sapping business, and one of the most important things a young owl has to do, if it is to thrive and successfully breed. Tawny owls generally mate for life, and once a pair has established a territory they will defend it doggedly from other owls. A good territory that offers safe nest sites and fruitful hunting areas for voles and mice is like gold-dust, and incumbent owls do not take too kindly to young pretenders trying to move in. The young owls, therefore, have to tread carefully as they continually call, so as to determine areas that are vacant.

Being out in the woods just after dusk, hearing these tawny owls engage in their vocal duels, is a haunting experience. Shakespeare immortalised the call in Love’s Labour’s Lost: “Then nightly sings the staring owl, Tu-whit; Tu-who, a merry note.” But despite the wonderful poetic flow of these lines, Shakespeare was not quite correct, for the tawny owl does not really “tu-whit-a-woo” as is popularly supposed, it instead delivers a more quavering “hu … hu-hoooo”, which is the main call of the male. The female’s principal vocalisation is the more screeching “kee-wick” call, which the Scottish naturalist David Stephen likened to a Native American war whoop.

Gilbert White, the 18th-century nature diarist, was also greatly intrigued by the subtle variations in the call of the tawny owl. He wrote: “My musical friend, at whose house I am now visiting, has tried all the owls that are his near neighbours with a pitch pipe set at concert pitch, and finds that they all hoot in B flat”. However, he recounted later of instances of other owls hooting in different keys. White wondered: “Do these different notes proceed from different species, or only from various individuals?”

The tawny owl is the master of concealment and during the day it is almost invisible as it sits high in a tree, often close to the trunk. You would have to know the owl is there and look hard before having any chance of detecting it. But sometimes other birds do the work for you, and the staccato alarm calls of song birds during daytime is often a sure sign that a tawny owl is about. Robins, chaffinches, tits, wrens and blackbirds all call together to mob the common foe. The poor owl looks bemused with its half-open eyes – all it wants to do is rest, but the mobbing will eventually get too much and it will soon fly off to try and find a more peaceful roost.

Although tawny owls are most frequently found in woodland, they do also occasionally occur in open upland areas, and once when camping in the Cairngorms I was surprised to see a tawny owl hunting at dusk miles from the nearest clump of trees. I’m not sure whether this was a resident bird or merely a nomad, although the latter seems unlikely as tawnies are notoriously sedentary in their habits and don’t tend to stray too far from where they are born.

The tawny owl is a wait-and-see predator, sitting on a branch or tree stump and carefully scanning the ground below, the large eyes gathering in every last vestige of meagre light. The acute hearing is also a vital aid in hunting in order to pick up the tell-tale rustle of a scuttling mouse. As well as rodents, shrews are important prey and bats are also sometimes caught.

The tawny owl always looks a rather benign bird when seen hunched up on a branch, which belies its true status as an incredibly efficient hunter. They are also well-known for the fierce defence of their young and bird ringers will wear helmets with visors to protect themselves when ringing young tawnies. It was a lesson learnt by the trailblazing bird photographer Eric Hosking in 1937, who lost an eye when trying to photograph a tawny at its nest.

Twenty-four hours after leaving hospital, he climbed back into the same hide to carry on with his photographic quest. He has been an inspiration for wildlife photographers ever since and his tawny owl images are still enjoyed by people to this day.