Migration is a way of life for most birds found in Ireland. Our nation sits with its back to the Old World and its face to the New World, so the variety of bird species reaching our shores is derived from two hemispheres. From across the planet, `our' birds come - to breed, stop off, or spend the winter. How these visitors reached our shores puzzled us for centuries.

So how do birds navigate so successfully over enormous distances and make a return trip to the same nesting site each year? Modern tracking results are revealing journeys once thought impossible - such as sustained flight for days at a time. Feats of endurance are one thing but their homing ability is even more impressive. Most of the youngsters fly solo to faraway winter quarters they have never seen.

The evidence - and some of the history behind its discovery - is pieced together in a simple way that brings a new coherence to the complex ways that birds navigate, the preparations they make before departure, and their decisions en route - such as when drifted off course by inclement weather.

In a nutshell, birds' array of sense far exceeds our own. Rather than relying purely on the sun and the stars for guidance, birds make use of something we cannot sense - the Earth's magnetic field. Overall they integrate a range of global phenomena, including patterns of polarised light visible (to their specially tuned vision) in the sky.

This spectacular book is a must for anyone who has ever wondered how and why these seemingly fragile creatures make such gruelling journeys.