feathers

Master Mimic: The Superb Lyrebird

As I wander  though the temperate rainforest of Victoria, I am, as always, surrounded by the sound of bird calls emanating through the forest. There are many birds with beautiful and distinct calls, but in my opinion, there is one that takes it all one step further.

I am on the hunt for one of Australia’s most famous impersonators.

Kinglake National Park, just a short hour’s drive north of Melbourne, is home to the Superb Lyrebird (Menura novaehollandiae). The star of the 10-cent coin, this bird is one of Australia’s most intriguing species. This ground-dwelling, brown Passerine may appear drab at  first glance, but a closer look will reveal a somewhat unique existence. 

Kinglake National Park

Kinglake National Park

The Mountain Ash forest of Kinglake National Park is an ideal place to start looking for lyrebirds. First, I keep a look  out for the eye-catching tail plumage. A lyrebird’s feathers rise up to form a display of brown, grey and gold – this the first tool the male uses to attract a mate.

But the tail is not the only thing I’m searching for, and neither is it the only way the male impresses the ladies. The lyrebird doesn't reveal its true talents until it opens its mouth. This is where the male shows what he’s really made off – he’s got a killer singing repertoire.

Not only does the male’s song consist of elements of his own, but also mimicked sounds and noises he hears in his forest home. The impersonations allow me to track down the male lyrebird in the dense undergrowth.

Sure enough, as I walk along the track to Masons Falls, I hear the call of a lyrebird.  After a bit of sneaking and searching, I find him just off the path. He is positioned on his “display platform” (a mound of bare soil amongst the undergrowth), belting his little heart out, trying to lure in the females.



Most commonly, this includes the calls of other birds, such as the kookaburra. Yet the lyrebird has even been known to mimic a camera shutter, car alarms and chainsaws (although these human-related noises may be limited to the captive population, as this has not actually been observed in the wild).

There is still uncertainty surrounding the question of why lyrebirds and other species use mimicry, but perhaps the required complexity helps females to spot high quality mates. Recent research has also suggested that lyrebirds match their dance movements to specific songs, introducing another layer to their complex routine.    

The beautiful, unmistakable tail plumage of a Superb Lyrebird. 

The beautiful, unmistakable tail plumage of a Superb Lyrebird. 

 

If you’re looking for the same experience, I suggest heading up there at the peak of the breeding season in winter, when the males are calling the most intently (although they have been known to sing all year!).

Hopefully you’ll get lucky and witness one of the most complex and beautiful bird songs Victoria has to offer.

The Science of Feathery Flight

A group of caspian terns take off. 

A group of caspian terns take off. 

Humans have always been fascinated with flight, and many of us are familiar with the cautionary tale of Icarus who, having donned wings made of wax and feathers, flew too close to the sun.

While there exist many species of animal able to glide through the air, only birds, bats, and insects have evolved the ability to stay airborne through the flapping of their wings. Of these three, it is the birds that top them all in their ability to fly at speed, with great endurance, over the longest distances, and while carrying the most weight; and so it is the birds that I will be discussing in this article. 

Before we discuss flight, we must first understand the structures used by our feathered friends to take to the air – their wings! The bones in a bird’s wing are equviliant to the bones in your arms and fingers, only they have evolved over time to specialise in flight. Feathered wings are light, flexible, dynamic, and easy to fold away when they’re not being used. Wing bones are light and hollow, joined at the shoulder, and powered by large chest muscles. Whist in the air, the elaborate set of bones and tendons allow for fine-tune adjustments to be made to the angle of the wing, allowing for the most efficient flight possible. The wings normally control height and speed, while steering is directed with the tail.   

Like a plane, birds must generate lift and thrust in order to fly. Lift rebels against the pull of Earth’s gravity, while thrust counteracts the forces of air-resistance and drag. Lift is generated by the flow of air over a bird’s feathered wings, while thrust is generated by the characteristic flapping that we are all familiar with.

Of course, there exists a great diversity of bird shapes and sizes even within our own State of Victoria, and so the mechanism of flight can differ among different species. Particularly there can be great differences in the methods of take-off and landing relative to a bird’s size. Small song-birds such as the white-plumed honeyeater can take flight in an instant, while larger-bodied birds like the Black Swan require more take-off time. Likewise, landing can be difficult for larger birds which is why swans often prefer to do so on the water, whereas song-birds can use their wings and tail to break in the air.

White-plumed Honeyeater showing off it’s agility. 

White-plumed Honeyeater showing off it’s agility. 

Black Swans are beautiful but lack grace in the air. Note the large body and wings.

Black Swans are beautiful but lack grace in the air. Note the large body and wings.


When it comes to speed the Peregrine Falcon wins the sprint competition with the ability to dive downwards in the air after prey at a dazzling 200kph. Meanwhile, at level flight, ducks and geese are among the fastest. Generally, birds rarely fly slower than 30kph in order to stay airborne.

Of course, while the flapping of wings is a familiar behaviour in birds, once in the air many birds choose the more efficient mode of staying airborne known as gliding or soaring. None do this quite like birds of prey like the Wedge-tailed Eagle or seabirds like the Australasian Gannet.


Wedge-tailed Eagle

Wedge-tailed Eagle

Australasian Gannet.

Australasian Gannet.

When the ground heats up from exposure to sunlight, the air above it also warms. This creates columns of warm air called thermals, which rise through the cooler (and therefore denser) air around them. Soaring birds use these thermals much like we use elevators – to effortlessly climb heights that would normally require a lot of time and energy! By spiralling around inside these columns of warm air, these birds can efficiently search for food, or travel great distances while on migration.

However, there are also other means of soaring. Cliffs and mountain ranges deflect wind in an upwards direction, creating updraughts which, unlike the temporary thermals, can blow for months at a time. If you’ve ever been to a windy cliff-face by the beach than this slope-soaring will be all too familiar – recall the gulls or sea-eagles that soared passed you in the breeze!

Flight is an amazing thing, and none perform it quite like the birds. So next time you step outside, spare a thought for any bird you might see flitting past, as they’re doing something pretty damn special.