The Snow Geese by William Fiennes

Books about birds have a resonance for me. A childhood spent in damp and insalubrious environments – freezing reservoirs, toppling clifftops, smelly sewage farms – with binoculars at the ready has bestowed one of those gifts that, as Iris Murdoch might have said, is the greater for being pointless. I can recognise and name, without consciously registering them, most British birds. To read William Fiennes's The Snow Geese, an account of one man's pilgrimage across the Americas, tracking the migration of the geese, who breed far in the Arctic north, was therefore a special pleasure.

I am also drawn to books that take their impulse from other books. For many people, the original Snow Goose by Paul Gallico remains a kind of icon. For all its feyness and sentimentality (perhaps because of those factors?), that slender book strikes some weird archetypal chord. Fiennes is generous in acknowledging his debt to its role in his imaginational life. Indeed, a generosity of spirit is one of this book's most attractive features, both in what is described and what one infers about the author.

Although ostensibly about the snow geese and full of fascinating insights into these graceful and evocative birds (the original scientific name for the snow goose was Anser hypoborea, "goose from beyond the north wind"), the book is a vehicle for many other observations. Many are about the characters Fiennes meets on his journey. For me, though, none of those people, entertaining though they often were, had as much appeal as the author. I found myself wanting to hear more about him. What, for instance, was the mysterious illness that laid him so low and led him to take up an interest in birds comparatively late in life?

Illness, in fact, is an important strand of this multi-stranded book. One of its threads is a discussion of homesickness. As a psychologist, I am interested that there is almost no literature on this topic. Though there must be others, this is the only book on the subject that I can recall reading. "In 1668 a Swiss physician, Mulhausen, proposed that it be known by the term 'nostalgia', a word he had constructed from the Greek nostos, meaning 'return', and algos, meaning 'suffering'". From the sound of "nostalgia", one can "define the sad mood originating from the desire to return to one's native land."

Fiennes's discourse on homesickness is prompted by his sojourn in hospital, for the sickness from which was born his desire to track the geese. This is linked to Homer's Odyssey and the wandering hero's sojourn with the seductive nymph Calypso. In this, one of the great passages in literature, Odysseus' nostalgia recollects not just Ithaca but also his faithful wife, Penelope, whose human charms, so seemingly inferior to those of the nymph, are ultimately what compels the hero's return.

It is this playful interweaving of detail that gives the book its charm. But it was the birds that held me most in thrall. I found I was skipping through the human encounters to get back to the fascinating information about migration. For example, "In the 1950s the German ornithologist Franz Sauer suggested that birds might refer to the stars to determine their migratory direction." Another ornithologist studying buntings placed them in circular cages so that only the sky was visible to their eyes. He learnt that "a bunting in a migratory condition stands in one place or turns slowly in a circle, its bill tilted upward and its wings partly spread and quivering."

Then he cunningly inked their feet and placed blotting-paper in their cages. They didn't write the Odyssey, but their footprints revealed that in the autumn they hopped south, while in spring the buntings tended to hop north. In the absence of alternative information, they must take migratory data from the night sky.

Hurrah for the buntings and the snow geese and their brilliant, untutored navigation skills; hurrah for the ornithologists who study them simply because they are there and make up part of one of life's unsolved mysteries; hurrah for people such as William Fiennes, who follow them simply because they are fascinated, and not for thought of any tangible profit. I hope he makes a tidy sum with this book, though – he deserves to.

Salley Vickers's novel 'Instances of the Number 3' is published by Fourth Estate