A few years back when my mother was still alive, we would go to a nearby convenience store for coffee, my parents and me. And there was a nearby church with a couple of towers. We noticed something odd. The birds, who were apparently perched on the towers, would fly off the tower, then circle the tower, then land on it again.
Why on earth would birds do such a thing? Does anyone know?
[BTW, I don’t know if this is the right forum, but I wouldn’t mind Cecil considering this question. But in the meantime, I submit it to you, my fellow board members…]
I’ve seen pigeons and crows do this on windy days and they appear to just enjoy riding the air currents. I don’t know why they’d do it on calm days. Flocks of birds may also leave their perches if startled by a hawk, then return to their perches when the hawk is gone.
Sometimes they are jockeying for position in the flock sitting order, sometimes they are youngsters practicing their flying… sometimes it is just the group trying to get going.
Birds that are insect eaters do what is called “hawking”, and may resemble what you saw - a bird will perch until it sees a bug, leave its perch to go catch the bug, and return to where it was. Usally, you can tell when a bird is hawking because it flies a bit erratically while catching the bug.
If they were pigeons, though (likely on a steeple) I’d go for the first idea - social birds put a bit of effort into establishing the proper perching locations for each, and the flocks go through pretty constant reorganization.
Birds often take wing when they detect a predator. If they remain perched, they become easy pickings, but flying in a flock makes it almost impossible for a predator to attack them. Birds have hollow bones (which facilitate their ability for flight) and if a hawk hits one of them, they both can go down. The predator must be careful and birds in a flock make it harder, unless the bird is the last one. (Elimination of the weaklings.) In fact, many birds, including crows and even smaller birds, will attack a hawk to get it out of their area.
I’ve always assumed it was because one of them took off, and the rest just found themselves caught up in flocking behavior. And they were all like, “I meant to do that.”