Fly Away Peter is an important work in Australian literature, and is on the Senior English curriculum in some states.
The novel touches on a range of themes which are common in explorations of Australian identity. Its setting in the First World War draws our attention to the ANZAC legend, and gives us a powerful sense of the experience of the men who forged that legend. The relationship with land is explored; Jim feels he belongs to the land as much as Ashley, who owns it; Ashley accepts this with laconic good humour. The boundaries of class and experience are palpable - Jim has grown up with a hardworking but violent and resentful widower father, and Ashley has had a privileged schooling in Europe - but they have a quiet rapport which transcends their differences.
The central motif of birds gives the author the opportunity to explore a range of themes. The miracle of bird migration becomes symbolic, echoing Jim's journey across the globe to the war. The notion of the 'bird's eye view' is explored. Like a migratory bird, Jim holds a 'map' of the swampland in his mind, whilst also seeing the detail of grass, undergrowth and water. A flight in Ashley's biplane gives him a view of the landscape which confirms his mental map. Later, in the trenches, he seems to go out of himself and see the battle as a map - while he is present in the mud and heat of battle, part of his perception observes, detached, from above.
Time - and the meaning of how we exist in time - is also a key theme in the novel. Imogen's comment that "A life isn't for anything; it simply is" is reinforced throughout. Her photographs of birds capture them in time, and give them a permanence they do not have in nature. The skeleton of a woolly mammoth, which rotted where it was killed with flints by early humans, lies where it fell and is unearthed as the trenches are dug. In this context the seemingly all-consuming 'machine' of war becomes merely a blip. As Imogen watches a surfer who repeatedly falls from his board, which rises behind him like a tombstone, at the end of the novel she cannot help, in spite of grief, to see that life goes on in all its power, exhilaration and tragedy.
Some readers identify a link between Jim and Imogen and Adam and Eve, with the estuary as the garden of Eden. This subtle parallel is used by Malouf to explore the key theme of innocence and experience. The idyllic "eden" of the estuary contrasts boldly with the hellish trenches. The novel consists of dualities: war and peace, life and death, innocence and experience, wealth and poverty, natural and man-made. However, these binaries are tinged with ambiguity. While the 'sanctuary' is idyllic, it is in this time and place of 'innocence' that Jim saw his brother killed on the farm, and had to live with the venomous and destructive despair of his father. Conversely, in the trenches, friendship is rich and the bird life is miraculous.
Malouf was regarded as a poet before he wrote novels, and much of his writing in this novel is poetic. Malouf himself describes it as a novel which explores ideas (such as the meaning or purpose of life) rather than story.