David Attenborough's Natural Curiosities: Magical Appearances

Sir David Attenborough examines the mysteries behind some of nature's most fascinating creatures and plants. The mystery of where some animals disappear to each year puzzled early naturalists. Do swallows hibernate in mud or under water? Where do our butterflies suddenly appear from each spring? The discovery of the swallow's epic migration and the butterfly's magical transformation were scientific stories cloaked in mystery and controversy.