Hummingbirds are a glittering, sparkling collective of over three hundred wildly variable species. For centuries, they have been revered by indigenous Americans, coveted by European collectors, and admired worldwide for their unsurpassed metallic plumage and immense character. Yet they exist on a knife-edge, fighting for survival in boreal woodlands, dripping cloud forests, and subpolar islands. They are, perhaps, the ultimate embodiment of evolution's power to carve a niche for a delicate creature in even the harshest of places.