When flamingos need some exercise and pain relief for arthritic knees, hydrotherapy—swimming in a pool for physical therapy—can do the trick. Columbus Zoo and Aquarium zookeepers take Martini and excited flamingo buddy Haleakala over to the manatee building for a swim. “Pink dinosaurs crossing through,” Joy calls as they cross the street. “We kind of like to joke that they’re pink veloceraptors.”How do baby flamingos become pink? Plus: California Devil Rays Leap from the Pacific and the largest school of rays ever caught on film.