Studying old paintings can give us a surprising glimpse of historic natural history. In 1611, the Flemish painter Jan Brueghel the Elder finished his epic allegorical painting Air. In it, he depicted the Muse of Astronomy, Urania, reclining on a cloud as a menagerie of feathered birds surrounds her. But while studying the animals in the picture, one researcher spotted something far more intriguing: in the top right corner, there appeared to be a bat carrying a bird in its mouth. For most people, this might not mean much. But for the ecologist Pedro Romero-Vidal it set his mind racing,...