This image shows a bird flying over time. The photographer Xavi Bou took multiple photos of the same scene and combined them to show the trails birds form while flying. This isn’t the typical flow visualization we think of, but it is such a unique project that I had to share. The full photo series can be found here, I recommended at least taking a look, the whole series is beautiful. Some of his photos with multiple birds could give insight to flocking patterns, through I’m not an expert in that field so I can’t say for certain.