Tu-whit, Tu-who – A merry note

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European Tawny owl perched in a tree hole. — Photo by Dylan Dando

IT was two weeks ago, whilst reading Robert WC Shelford’s book ‘A Naturalist in Borneo’, published in 1916, that I reached the chapter entitled ‘Bird Notes’. The section on owls jogged my memory of a frequent visitor to my garden. I ventured outside in complete darkness in a windchill temperature of minus 4 degrees Celsius to catch sight of a Tawny owl perched on a telephone wire at its usual nighttime spot.

Caught in the beam of my torchlight, it uttered a ‘hoo-hoo’ and quickly flew off. The title of this column is taken from the final scene of Shakespeare’s little-known play ‘Love’s Labour’s Lost’, in which he appropriately describes the season of winter.

I returned to Shelford’s book and reread his detailed description of what he referred to as the ‘Bornean Owl, a subspecies of the Oriental Bay owl (Phodilus badius). Two species of European owls and two of Malaysian owls are described in this article.

Tawny owls

This species (Strix aluco) is also known as the brown owl and is native to deciduous and mixed woodland across Europe to western Siberia. It is also found in urban areas where there are gardens, cemeteries, and parks, even in central London. Its average weight, length, and wingspan are respectively 400 grammes to 800 grammes, 40 centimetres, and 93 centimetres. Its rounded head with a light brown facial disk surrounds its piercing dark brown eyes and with an upper body colouring of either brown or grey and pale underparts with dark streaks, it blends in with its chosen habitat.

With fewer wing beats than most other owls and distinctive rounded wing tips, its flight is silent. This bird’s big eyes, placed in front of its head have a binocular field vision of between 50 to 70 per cent and much better vision in darkness than humans. Its ear openings are asymmetrically placed to allow better directional hearing and are but slits under its facial disk feathers.

The female makes a shrill call of ‘Kew-wick’ and the male responds with a ‘hoo-hoo-hoo’ hence the derivation of ‘tu-whit, tu- who’. Its short, sturdy legs equipped with very sharp talons allows it to swoop down on its prey of mice and small birds with deadly accuracy.

Breeding

They usually breed as a monogamous pair from February onwards, building nests in holes in trees or buildings, forcefully defending their territory throughout the year. The female lays a clutch of two to three glossy white eggs each weighing 39 grammes.

These are incubated for 30 days before the downy chicks hatch only to fledge after 37 days. The mother feeds the chicks for another four months after they fledge and then the young owls take off to find new territories. These birds have an average life span of about five years.

Threats

This species of owl is particularly susceptible to avian malaria, which has increased in the last seven decades. Common threats are buzzards, golden eagles, goshawks, pine martens, and foxes although today increased urbanisation, habitat loss, and the destruction of mice habitats through pesticides are major threats.

Barn owls

Apart from desert and polar regions, this species (Tyto alba) is the most widely distributed owl on our planet to include the Eastern Barn owl found in Peninsular Malaysia’s plantations. Sadly, in my neck of the woods in rural Somerset, England, I have not seen a Western Barn owl in the last 20 years. Probably the reason for this is related to changes in farming techniques and crops aggravated by Brexit with British farmers now denied massive EU farming subsidies for certain crops.

These birds have traditionally over time nested in farm outbuildings and barns many of which have now been converted to holiday lets thus providing the farmer with an extra seasonal income.

Characteristics

Its distinctive feature is its heart-shaped, white face with black staring eyes surrounded by light brown upper head and nape with a white breast and legs. This bird’s wings are a slightly darker shade of brown and mottled with white and brown bands best seen in flight. The wingspan, on average, reaches 88 centimetres. Females weigh 530 grammes and males are lighter at 480 grammes. Its square tail and its haunting shriek (for it does not hoot) are other easily recognisable features.

Hunting and diet

These owls rely mainly on their very acute hearing when hunting in total darkness but when hunting by day face mobbing by seagulls, magpies, and rooks. The Malaysian species particularly hunts in oil palm plantations whereas the European species prefers open grassland where voles, mice and other rodents and spiders are readily available.

Breeding

The majority of these birds nest between March and June when prey is easy to obtain, and two broods may be produced each year. Again, these are monogamous birds with nests built in tree holes, crevices in cliff faces, farm outbuildings, and even in church towers. Their nests are lined with dry regurgitated pellets.

The female lays a clutch of five small white eggs which hatch after 30 days with greyish-white downy chicks. The male owl feeds the owlets and within six weeks they reach adult size and fully fledged after nine weeks of hatching.

Threats

With an average life span of four years, winter cold and snow-covered landscapes restrict their diet with deaths caused by starvation. Many suffer vehicle traffic deaths when caught in a car’s headlights. Parasites also take their toll as barn owls harbour fleas and feather lice, tape worms, and other gut ailments when feeding on infected prey. Pesticides add to their toll.

Oriental Bay Owl

This owl is often mistaken for a barn owl and is found throughout Asia living in tropical rainforests, plantations, and mangrove swamps, places where there is an abundant food supply. This relatively small owl, with a length of 25 centimetres, weighing 285 grammes and a wingspan of 203 millimetres, is easily recognised by its heart-shaped face and ear-like extensions on the top of its head.

Deep chestnut colours adorn the top and back half of their bodies and tan-creamy coloured chests distinguish these owls. These birds hoot as well as issue screams and high-pitched whistle sounds.

Breeding

They nest in holes in tree trunks from March to late May and the female lays three to five white eggs. These are incubated for about 39 days with fast developing hatchlings fed by the father on a diet of regurgitated frogs, lizards, rodents, beetles, grasshoppers, and spiders. For a detailed description of this owl’s behaviour, please refer to Shelford’s book.

This bird I was lucky enough to see on a very early morning misty walk near Borneo Rainforest Lodge in Sabah. Peering down at me, it seemed quite undisturbed by my presence!

Barred eagle owl

Found throughout Borneo, southern Peninsular Malaysia, Indonesia, Myanmar, Thailand, and Singapore, this owl is often known as the Malay eagle owl (Ketupa sumatrana) with an average length of 44 centimetres. Distinctive by its barred underparts, breast, and wing edges and horizontally extending ear tufts, its penetrating large dark eyes and upright stance, whilst perching, allows this bird to survey the world beneath; its large curved taloned feet ready to swoop down on its perceived prey. I have only once seen this species by day in a coastal nature reserve at Batu Pahat in southwest Malaysia.

The Barred eagle owl has distinctive horizontally extending ear tufts. – Photo by Jean Beaufort/Public Domain Pictures

Breeding

It is highly likely that these birds are monogamous and are devoted to a particular nesting site in a large tree hole. Just one white egg is laid with the hatchling appearing from February to March in Borneo.

Diet

Whilst really little is known about the dietary habits of this owl, it appears that it has a very diverse diet ranging from mice and rats to reptiles, snakes, birds, insects, and even fish. So very little is known about this bird of prey that here lies a challenge to Bornean ornithologists and potential Zoological PhD students!

Tonight, as I write this, outside temperatures are minus 6 degrees Celsius and my wood burning stove is firing away. I have no doubt that not even a single owl has ventured out of its nest locally here for its prey are also sheltering from the bitterly cold wind, whilst Malaysian owls are hunting and breeding!