Spotting winged warriors
FROM the time mankind fi rst gazed into the skies, birds of prey have been viewed with wonder and awe. It’s no surprise that eagles have always been symbols of power and falcons a metaphor for speed and agility.
People who might not necessarily be interested in birds still fi nd the sight of raptors irresistible. But the problem with studying our raptors – for both the avid bird- watcher and the casual observer – is that different species can often look the same.
The wedge- tailed eagle is pretty distinctive with its long wedge- shaped tail and giant size but what of smaller eagle species, and hawks, goshawks and falcons? High in the sky – where they are generally spotted soaring on thermals – it can be diffi cult to determine distinguishing features, such as colour and wing and tail shape.
Here, Birds of Prey of Australia comes into its own. It is billed in its secondary title as a fi eld guide and it is easily the most comprehensive book on raptor identifi cation produced in Australia.
But the book is more than a mere fi eld guide, a second section forms a handbook that goes into great detail about each of the diurnal birds of prey found in Australia.
Once upon a time, a comprehensive and specialist book such as this would have had a limited audience, but there is a growing interest among the general public not just in raptors but the environments they inhabit.
There is even a recently released Australian fi lm, Healing, which features an injured wedgetailed eagle and its prisoner- carer as its stars.
The rehabilitation of injured eagles is also a subject covered in Birds of Prey of Australia, a section of it outlining the threats raptors still face in humankind’s world.
While persecution, poisoning and even the new threat of windfarms are subjects covered in other books about raptors, this one concentrates fi rmly on what makes Australia’s birds of prey special and how our enjoyment of them can be maximised.
In this regard, Birds of Prey of Australia has come up with an ingenious solution to end fi eld identifi cation confusion.
Among many changes from the fi rst edition published 15 years ago, the latest work produces split images of the most diffi cult species to identify, so plumage and wing shape can be compared directly.
The illustration showing split views of the wedge- tailed eagle and the white- bellied sea- eagle clearly show the more prominent “fi ngers” of feathers at the wing- tips of the sea-eagle and the shorter tail.
Along with the beautiful colour illustrations and photographs showing birds both perched and in fl ight, there are also head- on diagrams that show the angle of the wings.
The swamp harrier, common in Tasmania in the summer months, has an upswept wing pattern, which the book shows head- on as a shallow V- shape.
The book also informs us that another sure way to identify a swamp harrier from other similarly sized birds of prey is the patch of light- coloured feathers on its rump.
In true fi eld guide style, brief detail is given about species, the emphasis being on identifi cation, but in the handbook section, there is much fascinating information about the swamp harrier as a species.
I didn’t know, for instance, that when the harriers – the only Tasmanian raptor to cross Bass Strait – return to the mainland after the breeding season they form communal roosts.
It is believed such roosts “might function as information centres at which some birds learn where others are hunting successfully”.
And in the same section, light is shed on the wonderful aerial displays of wedge- tailed eagles.
“At all times of the year, but particularly in the breeding season, pairs spiral up in a mutual soaring display that might culminate in rolling and foot- touching when the male dives at the female.
“The pair then descends to mate on a branch near the nest,” writes author Stephen Debus, who also describes aerial passes in which the male presents the female with food, and courtship in which “mated birds perch together, extend their necks and touch bills”.