Tonight, the documentary series gives a bird's-eye view of South America, as condors soar along the Andes, scarlet macaws explore the heart of the Amazon and hummingbirds and vultures see the continent's greatest sights. It is a journey that includes Machu Picchu, the Nasca Lines and the cities of Rio de Janeiro and Santiago. In Patagonia, giant petrels shadow killer whales as they hunt seals by stranding their huge bodies on the beach. At Iguassu Falls, dusky swifts dive through the cascades to huddle in communal roosts while hummingbirds bathe below. In a secret Andean location, condors soar in flocks over 40-strong and scavenge on casualties from herds of fighting guanacos. Elsewhere, a mother condor gently pushes her youngster to the edge of a 200-metre cliff, as flight school begins.