The tawny owl makes a compelling case as Britain's best loved bird of prey

The wonderful tawny probably supplies our default image of all British owls. It is our most abundant and widespread species, with only the mountainous Scottish Highlands and the largely treeless Hebrides beyond the bird’s limits. Yet we must also acknowledge tawny owls are in decline; their re-designation as an amber-listed species due to a 10% contraction in range. Britain has become a rather impoverished place for this family of owls; one factor might be the overlooked matter of light pollution. Another concern for several species is secondary poisoning from rodenticides.

With a current British total of 50,000 pairs, the tawny is still the one owl that many of us are likely to have seen — perhaps as a silhouette perched momentarily on a rooftop or a broad-winged, brown shape floating silently through the trees. Tawny owls come readily into towns and villages and will breed in many suburban woodland patches, leaving them to hunt across domestic gardens after dark.

As well as being our largest owl, it is also probably the most versatile in matters of diet. Rodents are a staple, but so, too, are songbirds snatched as they sleep. A large starling roost in Lancashire last century contained a million birds and supplied a life of relative leisure for the local tawny population. Yet they can tackle a range of other prey, including young hares, rabbits, squirrels, weasels, as well as more eclectic fare — fish, frogs, newts, even woodpeckers.

Titbits as large as adult rats are swallowed whole. A main source of information on the birds’ diet are the pellets of undigested fur, feathers and bones that owls regurgitate daily at roost sites. Each species of owl produces a pellet that is instantly recognisable — black, smooth and almost shiny in the case of the barn owl, but broad and grey coloured for tawny owls.

Pellets are a good indicator that an owl pair is resident in an area, but clearest of all is the tawny owl’s extraordinary vocalisation. The male produces the inimitable sound from late autumn onwards and it can be heard in midwinter. It has given rise to a mnemonic that, at one time, every child would have committed to memory: tuwhit-tuwhoo. However, this transliteration is a conflation of two sounds made separately by male and female birds and its precise structure warrants a little teasing out.

All tawny owls have a sharp disyllabic warning or contact call—keewick (or, if you prefer, tuwhit)—that they deliver at regular intervals, as they move in tandem through their territories. The male also then produces a separate song. This is itself in two parts: the first is a clear, low, drawn-out hooting hoo-ooo; then followed by a silence of several seconds, after which he delivers a more sustained, rising and tremulous oo-ooo-o-o-o. The complication arises partly because the pause left by the male is often punctuated by a call from his mate.

It is fitting that one of the most celebrated avian sounds was first diagnosed on the page by the Bard. In Love’s Labour’s Lost, Shakespeare wrote: ‘Then nightly sings the staring owl: Tu-whoo;/Tu-whit, Tu-who—A merry note.’ In these two lines, we have perfectly evoked the two-part male song, intersected by his mate’s sharper call. The only part with which I dare disagree is the idea that it is in any way ‘merry’. It is certainly beautiful and unforgettable, but it is also solemn and, if the background conditions are just so — perhaps a touch of ice and moonlight and stars pricking the blackness overhead — utterly mysterious.

The novelist H. E. Bates once suggested that a nightingale’s song consisted of exquisite phrases wrapped around silences and it was the shape and eloquence of the latter that made this nocturnal performance so affecting. In precisely the same way, it is the pause in the male tawny’s notes — and his apparent recognition that an absence of sound is as moving as song itself — that turns a duet by these owls on a dark winter’s night into one of the greatest musical performances in all of British Nature.