Take off in a ‘snowstorm’ of geese and glide under San Francisco’s Golden Gate Bridge with pelicans. This is the world on the wing – a world with secrets known only to the birds. The countdown to Earthflight’s epic adventure begins in the Gulf of Mexico as five million snow geese prepare to fly the entire length of North America. Each spring, these families of geese head north on a gruelling 3,000-mile journey to the Arctic to breed. Cruise with them on a tight schedule along familiar ‘flyways’, taking a route across the parched Monument Valley and up the Mississippi before catching skyscraper-induced thermals over New York City. One unwelcome fellow traveller is the bald eagle. At every opportunity it plummets into the flock to grab a meal. But it’s salmon not geese that lure the eagles away to Alaska. As the annual salmon run kicks off, duck and dive among squabbling grizzly bears as the eagles snatch a share of the feast. At the other extreme, brown pelicans seem to enjoy a far more relaxed Californian lifestyle. In the balmy seas of Baja, join a young pelican on its hunt for fish. It takes its cue from the breaching humpback whales and massing dolphins way below – that’s where the schools of anchovies are sure to be. Hitching a lift with pelicans on their leisurely route up the golden coast reveals the never-filmed-before behaviour of devil rays somersaulting out of the water and the daytime spawning of thousands of grunion fish. Eventually the pelicans make their final descent into San Francisco Bay, gliding past Alcatraz and slipping under the Golden Gate Bridge.