I discovered a nice place to take photos from flamingos in the Camargue Nature Reserve in southern France back in 2012. You can park your car at the shoreline of some salt water lakes and take your chair, sit down and watch - if you want. I couldn't sit down. I had to walk to different places. Especially in the morning or evening, the flamingos moved from their feeding to their sleeping grounds. There was constant air traffic!
I 'only' owned a 7D with the 70-300 L lens at that time, so all these pics were taken with that equipment.
Just watch the bird in the center of the last picture - can you see it? There's not 1 but 2 flamingos flying side by side, from the head to the toes in exactly the same position.