The mechanisms of pigeon homing are still not understood. in particular how they determine their position at unfamiliar locations. The "gravity vector" theory holds that pigeons memorize the gravity vector at their home loft and deduct home direction and distance from the angular difference between memorized and actual gravity vector. However. https://www.kingarte.com/product-category/food-servicecommercial-kitchen-equipmentfood-preparation-equipmentprep-tableswork-tables-industrialrestaurant/