Two falcons, two worlds. The gyrfalcon is the largest falcon on the planet and lives in the Arctic, among the snow and rocks of Greenland, Scandinavia and Siberia. Some are almost entirely white, perfect camouflage in the tundra. In the Middle Ages it was the falcon of kings, a gift reserved for monarchs. The common kestrel, on the other hand, is one of our most familiar neighbors. You have surely seen one hanging motionless in the air, beating its wings beside a road: this is its famous hovering flight, which it uses to scan the ground for prey. And it has a superpower: it sees ultraviolet light. Thanks to this, it detects the urine trails of voles, which glow for it like a treasure map. Speed, precision and extraordinary eyesight.