Hummingbirds in Slow Mo

Hummingbirds, the smallest and the most extraordinary birds on earth. They have no sense of smell, yet they visit 2,000 to 5,000 flowers a day, consuming twice their body weight in nectar. Their colour is not produced by pigment, but by the refraction of light. Their tongues are twice the length of their bills. They cannot walk, only perch. Sometimes to catch insects. For their size, hummingbirds have the largest heart and brain of all animals. Yet their 50 million year evolution is far from complete, as is our understanding of their biology. Since 2014, scientists have made a series of astounding discoveries, thanks notably to ultra high speed cameras. To fly, hummingbirds create not one, but two vortexes in the air, one per wing. They don't detect the sugar contained in the flower's nectar, but its carbohydrates. To swallow it, their tongues act more like pumps than sponges. Their sense of sight and ability to avoid collision are closer to those of insects than birds. Travelling from the Andes to Alaska, through the tropical forests of Central America, embark on a scientific journey to marvel at the secrets of these evergreen beauties.