I recently found out that a term used to describe a flock of parrots is a pandemonium. Living in south Florida I occasionally get to see the North American wild parrots, called Quaker parrots. They like to invade the large sea grape trees, where they become all but invisible. If it wasn’t for their raucous cacophony, which is indeed pandemonium, you would not know they were there. I have tried to photograph them with my little compact camera, but my photos are not nearly as good as the one below. As they fly, the pandemonium of parrots is more like a ball of birds than an organized v-formation. They are loosely grouped together.
At what point, I have asked myself, does a loosely confederated ball of birds become a group? What are its parameters? Thinking about this in an informal way, we can say that there must be some mathematical cohesion, because all the birds light from the tree around the same time when spooked, they launch into a similar trajectory, they occupy a confined region of space in flight, and they end up in the same place, the sea grape tree. Not to mention they belong to the same species, and very likely constitute a single extended family.
On the other hand, look at the organized, geometric structure of a flock of pelicans in flight (which I have also tried to photograph, but my photos are not as good as this one). We can discern that the pandemonium of parrots and the pod of pelicans are both groups, having characteristics that all groups must have. Clearly, though, the two groups are structured differently. One is an amorphous blob, the other a linear stratification.
This is hardly a lecture in bird psychology, but rather the structure of flocks of birds should used as a metaphor to illustrate the continuum of group variety and homogeneity. Can we generalize the visible organization of these images to people groups?