Penny Olsen muses on the characteristics of some of her favourite birds
Penny Olsen muses on the characteristics of some of her favourite birds
A wise old owl sat on an oak
The more he saw the less he spoke
The less he spoke the more he heard
Why aren’t we like that wise old bird?
On a chilly July evening, the wind howled as I walked to the O’Connor shops in Canberra’s inner north. As usual, I hoped to hear a ‘whoo-hooo’, but, as usual, I didn’t. I wasn’t hoping for an encounter with a friend, rather an owl, a spectacular one that has moved into Haig Park. I knew the chances of hearing its mournful cry were low. Owls tend not to call in windy conditions and it was well into the breeding season, when everything quietens down. Owls make their loud, far-carrying calls to advertise territory and to attract a mate. They have other softer calls when in close contact.
The Haig Park owl is a Powerful Owl, apparently living solo, far from its nearest known neighbours in the Brindabella Ranges. It was first spotted in Canberra two years ago, in late 2014, and has achieved some fame, gaining a name, Powl, and attracting hundreds of bird-loving visitors. It sits majestically, high in a tree, sometimes clutching the remains of a cockatoo, Feathertail Glider or young Ringtail Possum, staring silently down at its admirers.
In some cultures, a meeting with an owl is to be avoided. Seeing or even hearing this messenger from the dark world means a death or great evil is imminent. Shakespeare’s owl is the ‘fatal bellman’, shrieking for King Duncan; in Medieval England, the bellman rang the parish bell when someone was near death. Throughout history and wherever they occur, owls have had cultural significance, whether as portents of good or evil.
Why are owls so evocative? That they are strangers to sunlight, denizens of the dark, conjures an obvious association with evil, the dark side. Their otherworldly shrieks and hoots rend the night. Their ability to rapidly swivel their heads around to look straight over their backs brings to mind The Exorcist. Their silent, flitting flight can make them seem menacing, and call to mind a spirit. Indeed, some Australian Aboriginal groups regard owls as the sacred spirits of women—good owls. Elsewhere, it was believed that witches got up to mischief disguised as owls—bad owls.
Not least, owls’ big, rounded heads, with large, forward-facing, unblinking eyes, inspire us to anthropomorphise them as intelligent, vigilant, all-seeing, all-knowing. In Greek mythology, an owl was linked to Athena, Goddess of Wisdom, who was often pictured with one perched on her shoulder. As Athena’s symbol, the owl (a Little Owl) was used on Greek coins, and became linked with wealth and, through funding of armies, protection. Ticking off on wisdom, wealth and protection, the Little Owl was truly a bird of good-omen.
Today, owl images are often good luck symbols and collectables, and owls make a strong showing among cuddly toys and books for children. The link to Athena has survived in the association of owls with education and in sayings such as ‘wise old owl’ and ‘the wisdom of owls’. In Winnie the Pooh, the character ‘Owl’ has a reputation of being brainy: as Pooh says, ‘if anyone knows anything about anything … it’s Owl who knows something about something’. The ancient link between owls, witchcraft and sorcery is picked up in the Harry Potter books, in which several owls feature as emissaries between the magical and the Muggle world.
But are owls really smart and all-seeing? Like the wise Owl in Winnie the Pooh, who gets confused and misspells even his own name as Wol, owls aren’t particularly intelligent. Unlike some birds, they can’t create tools or recognise themselves in the mirror—abilities sometimes (controversially) considered to be signs of higher cognitive ability.
Those features of owls that lead us to attribute human characteristics, create superstitions and assign supernatural powers are really just adaptations to their lifestyle. Do owls have super eyesight? It depends. To see in dim light it is important for eyes to gather all the light they can. Owls have very large eyes for their body size and their pupils can expand greatly, which lets in more light. Owls also have a large number of rods, light-sensitive structures, in their retinas. This allows them to see far better than humans in dim light (they can’t, of course, see when there is no light). Rods are also sensitive to shape and movement. However, owls have few cones, which detect colour and provide fine spatial acuity. So, overall, owls have sacrificed colour and acuity for night vision. In fact, they can’t see objects close to them well at all, instead relying on special sensory feathers around their face and feet.
Against the stereotype, the eyes of some owls are not so huge: Barn Owls, for example. What they lose in night vision they gain in acute hearing, to such an extent that they can hunt in absolute darkness, and accurately zero in on prey hidden under snow or leaf litter. These owls have asymmetrical skulls, with one ear opening higher and larger than the other; sound arrives at (minutely) different times at each ear. The Barn Owl’s feathery facial disc captures, amplifies and funnels sounds to the ear openings. If the owl hears prey and turns its head so that the sound arrives at the same time in both ears, its prey is immediately in front of it. In addition, the auditory area of the owl’s brain is far more complex than that of day-active birds; it can create a mental spatial map from sounds, which helps it not only to hunt but also to navigate through the night.
And what of the owl’s ability to rotate its head through such a wide arc? Because it has large eyeballs (they are actually tubular shaped), which must be packed into the skull around the brain, they can’t move in their sockets. This is where the swivel neck comes in handy. To allow the swivel, owls have extra neck vertebrae, twice as many as the typical bird, and adaptations that keep their blood supply from being cut off when they snap their neck around to look behind.
Are owls sneakily silent? Owls need to have silent flight to catch their prey, which also have acute hearing. When most birds flap their wings, it creates noise. But owls’ broad, extra concave wings are made for lift, so owls do not need to flap as much as the average bird to stay in the air. In addition, owls have special soft-fringed flight feathers that minimise sound when they flap, and some species have extra soft plumage that doesn’t rustle when the owl moves. This gives them the ability to swoop unheard on unsuspecting prey, rather than pursue them at speed. Once again there is something of a trade-off: to an owl, stealth is more important than speed.
Australia is home to nine owl species: five hawk owls (genus Ninox) and four barn owls (Tyto). As the name suggests, hawk owls are somewhat hawk-like, with rounded heads and brown-grey plumage, and they have less extreme adaptations for night life; barn owls are more fully nocturnal and can be recognised by their distinctive heart-shaped faces. The Powerful Owl (Ninox), which is 60 cm tall, from the top of its head to the tip of its tail, and the Masked Owl (Tyto) are the biggest owls of their type in the world. Our smallest species, and the most widespread and familiar, is the Southern Boobook Owl, its name imitating its best-known call.
During the day, owls rest quietly, perched high up in a tree, or in a tree hollow, rarely under the eaves of buildings or in outbuildings. Occasionally, they are found by experienced bird lovers who detect their presence from their white excreta, pellets, or tufts of fur or a scattering of feathers below the roost. Mostly, we see owls by day only after other birds have sprung them. Many birds do not tolerate owls in their territory—particularly in the breeding season when they fear for their young—and, if they discover them, they create a racket, screeching and mobbing the owl in their attempts to drive it away.
Frogmouths and nightjars are often mistaken for owls but, while they do have some similarities in appearance and habits, they belong to a different family of birds. A major difference is that owls catch their prey with their taloned feet, whereas members of the frogmouth family catch prey with their beaks.
Presumably, the Haig Park owl is a subadult and will one day leave to find a mate, but wouldn’t it be fabulous if it became the founder of a Powerful Owl population in the Capital’s suburbs? It can be a surprise to learn that such a large nocturnal predator lives among us all but unnoticed. In fact, it was not until recent decades that we realised that Powerful Owls are not uncommon in suburban and even central Sydney, Melbourne and Brisbane. Previously, it was thought that they only resided in subcoastal forests.
For the moment, Canberra has one permanent Powl, an imposing fiberglass sculpture that protects the suburb of Belconnen. The sculptor, Bruce Armstrong, chose the subject because of its traditional link with wisdom and in acknowledgement that a group of owls is known as a parliament.
Dr Penny Olsen is a natural history writer and research scientist based at the Australian National University. She is a former Harold White Fellow and has written for both children and adults using the collections of the National Library of Australia.