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.