Pigeons provide nourishment. Endangered Peregrine Falcons, for example, would not be staging a comeback without the pigeon as their prey base. Pigeons are benign residents. They do not compete with indigenous animals for food or shelter. And, contrary to popular belief, cases of pigeon diseases spread to humans are extremely rare and, in most areas, like Arizona, are nonexistent.
Pigeons have religious significance.
Common city pigeons are actually European Rock Doves. They are the biblical dove of love and peace. They helped honor the birth of Christ. They are the same birds as the pigeon that Noah released, which returned with the olive branch to signify the end of the Great Flood. Nearly all religions revere pigeons as holy birds.