NATURE NOTES - The owl but no pussycat

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WE were leaving Borsdane Wood just as the sun had set and were treated to a fantastic sight of a tawny owl.

He was sat just above our heads and as we approached hopped up a couple of branches where he could watch us ‘safely’. His head was bobbing and weaving as tawny owls do when they see something worth watching – which we obviously were!

It’s that time of year again when they start setting up territories ready for breeding.

As well as being our most common and widespread owl its other claim to fame is that it’s the owl of both fairy tales and horror stories whose tu-whit, tu-whoo of the night has become part of our rich literary heritage.

Under normal conditions courtship begins in late February. The male, during this period, can often be encountered hunting in daylight – this helps him find food and present it to his mate.

As he patrols the boundaries of his territory he screeches loudly to let his rivals and neighbours know ‘this is his patch’ and it also helps to attract Mrs Tawny! Long, wavering hoots are often heard, and sharp ke-wick calls, also. Cat-like screams – caterwauls - are also a common feature of tawny owl boundary disputes, but perhaps the least known yet most appealing, call is a soft, bubbling purr audible only at relatively close range, a soporific, affectionate sound that drifts gently through the trees, catching well the mood of calm, night-time woodlands.

When Tawny Owls they have found a good nest site seem to use it for years – evidence suggests that successive pairs tend to use the same sites for twenty or even thirty years.

There are well authenticated cases where sites have been used in excess of a hundred years. The widespread use of artificial nest-boxes has over the recent past, proved to be successful especially in urban areas. Tawnys don’t construct a nest and even a scrape is thought to be no more than the fortuitous creation of the male’s courtship behaviour.

But, because the breeding season is so long, by the time the eggs are laid, there is often a soft bed of pellets and feathers. Between four and six eggs are laid in April or early May. The eggs are left to the female to incubate, once the first egg is laid.

The male’s job from here until the eggs hatch is to keep a regular supply of food coming to feed the female. The eggs hatch (asynchronously as with laying) after 32 to 34 days, and the young enjoy a remarkably lengthy fledging period of usually 60 days but can be anything up to 86 daysThere are frequently two broods per year.

Tawny owls mainly feed on small mammals; in woodland bank vole, wood mouse, and shrews are most common, while in farmland field voles are more often caught.

Birds are also taken, especially in summer, when nestlings and fledglings are available, in urban areas it seems that house sparrows figure highly in their diet. Invertebrates can also be a significant part of the diet, especially earthworms and beetles.

They usually hunt from a perch, silently dropping down on their prey.