Up to half a billion monarch butterflies lie sleeping having overwintered in Mexico. As winter ends and spring arrives, the sun warms their wings and the forest comes to life as a cascade of butterflies take flight! Robot Spy Hummingbird is right there in the heart of the spectacle.

Clip taken from episode 2 'The North' of the second series of 'Spy in the Wild', narrated by David Tennant.

Catch up on the series on the BBC iPlayer here: https://www.bbc.co.uk/iplayer/episode...

Spy in the Wild is back in one of the most innovative natural history series ever presented. This time it deploys over 50 ultrarealistic animatronic Spy Creatures to go undercover across every region of the world. The 4 x 60 BBC One series captures some of the most extraordinary animal behaviour ever seen, filmed from inside the animal world.

Using special stateoftheart 4k resolution “Spy Creatures” the viewer is plunged into the very heart of the extraordinary lives of over 40 remarkable animals. They reveal previously unseen behaviour as animals gather, feed, fight and breed in among some of the greatest wildlife gatherings ever witnessed. This team of hyperreal Spy Creatures not only look like the animals they film, they behave like them too. Accepted by the families, these robotic lookalikes can not only film from an intimate perspective they also interact with the animals and so gain revelatory insights into their worlds.

Each episode explores a different climatic region of the world and is packed with its own menagerie of animatronic Spy Creatures and extraordinary animal subjects. They discover how the animals have adapted their behaviour to not only cope, but often flourish, wherever they live. At times, their subjects occur in incredible numbers creating astonishing gatherings, found nowhere else on earth. From the hot and humid Tropics, to the freezing Poles, the seasonal North and the world’s most spectacular Islands, this new series of Spy in the Wild will transport the audience deeper into the animal world than ever thought possible.

Narrated by David Tennant
Directed by John Downer
Music by Will Gregory