To get to his rooftop, Paul Wohlfarth passes by a gigantic stag’s head hanging in the hallway, climbs a wobbly ladder and slips through a narrow opening. The 64-year-old has been repeating these gymnastics for the past six decades. On top of his building is a fenced coop, housing more than 250 pigeons in different compartments. Wohlfarth, a roofer by profession, can recognize any of his birds in a flash. “That one with the blue band is a tippler,” he says. “It’s got a short beak, a wide eye. If you didn’t know, you’d think it’s a street pigeon. But there are a million breeds.”