The TAWNY OWL is the most common and widespread owl in Europe and perhaps the commonest raptor in Britain. It is the owl of fairy tales, whose tu-whit, tu-whoo of the night has become part of out literary heritage.
• Length: 37 - 39cm
• Weight: male 330 - 470gms
• Wingspan: male 95 - 100cm
Females are 20 - 40% heavier and their wings
5 - 10% longer.
• UK Breeding population: 19,000 prs *
(Approximate figures 2007)
It has had a variety of names over the centuries such as beech owl, Billy hooter, brown owl, brown hoolet, brown ullert, common brown owl, ferny hoolet, Gilly hooter, golden owl, grey (gray) owl, hill hooter, hollering owl, hoot owl, howlett, ivy owl, Jenny howlett, Jinny yewlet, screech owl, tawny hooting owl, ullet, wood owl and wood ullat.
The Tawny Owl is a chestnut-brown bird, boldly barred and streaked with buffs, blacks and whites to form a cryptic pattern. The breast is pale buff, heavily streaked with arrows of black-brown. A broad, rounded head has a prominent facial disc with deeply set dark eyes. Buff ‘eyebrows’ extend between the eyes to the bill. The tail is short and the wings broad and rounded. There is much individual variation in ground colour, from brown to grey (gray), but all plumage’s are highly effective in hiding the bird from the attentions of irritating small passerines at its daytime roost. It flies on soft, silent wings after dusk and is more frequently heard than seen.
The Tawny Owl has at least ten basic calls and the young five. There is some variation between male and female, and individuals can be recognised by their own tremolo and constant pitch. The familiar ‘hoo’ first uttered as a protracted monosyllable, followed by a long pause, then a faint monosyllable, a short pause, and finally a long, soft quaver, falling in pitch. The familiar ‘kewick’ is heard mostly in spring and summer. The female utters ‘erriee’ mostly at any time of the year.
Soft tremulous ‘guuoh gu gur-ruuh’.
Predominantly small mammals such as long-tailed field mouse, field vole and common shrew. Birds, fish and other small mammals may be taken, and urban Tawny Owls have become specialist House Sparrow predators.
The pair-bonding is mostly monogamous, though the males are occasionally bigamous, and long-term. Under normal conditions courtship begins in late February. The male, during this period, hunts more by daylight in order to present food to his mate.
As he patrols his territory he screeches so as to repel any rivals and also to attract the female. There is a good deal of attachment to traditional nest sites, and successive pairs tend to use the same ones 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. No nest is made, 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 4 and 6 un-glossed eggs are laid in April or early May. The eggs are incubated, almost entirely by the female, once the first egg is laid. The male feeds the female during the incubation period. 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 days. There are frequently 2 broods per year.
Tawny Owls, as with barn owls, are mainly monogamous but some males may be bigamous. The pair-bond lifelong and is maintained all year. Territories are established in the autumn when much calling and hooting can be heard. The male may clap his wings in display.
The nest is an unlined hole in a tree or the old nest of a Crow, Magpie or Grey (Gray) Heron. The 2 to 4 rounded white eggs are laid in March or early April and incubated, starting with the first egg, by the female for 28 to 30 days. The male feeds the brood for 21 days or so and the youngsters fledge after 32 to 37 days. The Tawny Owl is single brooded.
Some information extracted from the World Owl Trust www.owls.org