Why do pigeons spin in circles?
Similarly one may ask, why do birds spin in circles?
They are circling on updrafts - naturally occurring areas of hot air raising. It takes lots of energy for large birds to flap their wings so they search out and find an updraft that will take them very high. At great height they then sore to find another updraft.
Also to know, why do pigeons spin around?
If you see a pigeon that is pecking at seed but missing it, tossing seed backwards over its head when it manages to pick one up, twisting its head at an unnatural angle or upside down , looking dizzy , looking drunk or spinning in circles, then the most likely cause is pigeon paramyxovirus.
If you are interested in what role pigeons play, well, they are prey animals mostly- food for hawks, foxes, martins, etc. They are also omnivores, and help control insect populations. The seeds that they eat can be excreted in other areas, so they are also seed dispersers.