Why tawny owls are a hoot at the moment

This year's young have stayed with their parents for several months after fledging but are now driven off to find their own territories.

There is much competition with older males, the owls making their long tremulous hootings to establish ownership, sometimes engaging in some fierce fights. The female will sometimes hoot as well but her normal call is a sharp kewick. Both are most vocal on still overcast nights and call less when it is wet and windy or on moonlit nights when they are hunting more than calling.

A good territory with plenty of birds and rodents to feed on is hard to find and many young owls that have failed in this mission die of starvation later in the autumn. Once a territory has been won and the male has paired up, the two will stay together in the same area for life. A nest is built usually in the hole in a mature tree although a pair might take over a large magpie nest and will readily use an owl box (details from the British Trust for Ornithology).

They are most frequently found in deciduous trees and as well as the countryside will also inhabit urban parks, churchyards and some large gardens.

Tawny owls are not easy to see at night but by day a roosting one can often be discovered in a suitable evergreen tree in spring when there is less leaf cover elsewhere, roosting close to the trunk or in ivy.

In the countryside, tawny owls feed largely on shrews and voles although they will also take frogs, beetles and earthworms. In urban areas, their main prey species are sparrows and starlings but they will also take rats and grey squirrels.

Hunting is at night, the owl using its highly sensitive hearing and vision to drop on its prey. Some have even been observed using their wings to agitate bushes to flush out sleeping birds.

Tawny owl numbers declined, like many other birds of prey, during the 1960s because of the use of agricultural pesticides but have recovered with an estimated 19,000 breeding pairs in Britain but they are absent from Ireland, the Isle of Man, the Northern Isles and Outer Hebrides.

The longest continuous study programme of tawny owls in the world in the Kielder Forest inNorthumberland celebrates its 30th anniversary this year and has come up with some remarkable results as to how long-lived some tawny owls can be.

One female, called Boudica who wasringed in 1987, produced her first chicks the following year and, aged 21, still managed to hatch three more healthy chicks. But she failed to return to her nest box in the forest in 2009 and is thought to have succumbed to old age, just missing by a few months the distinction of being the oldest wild tawny owl ever recorded in Britain.

This year, volunteers working for the Kielder Tawny Owl project have found another female, first ringed as a chick in 1990 and still going strong. Last winter was a hard one for many tawny owls who found it difficult to hunt in the prolonged ice and snow. But a booming vole population this year should result in a good breeding season for them.

Sightings reported over the past week have included a European roller, spotted at Easington, East Yorkshire on Sunday and a Lapland bunting seen at Oxenhope, West Yorkshire the same day.

A little stint has been seen at Nosterfielld LNR, North Yorkshire while a black redstart was sighted at Langsett, South Yorkshire.

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CW 18/9/10