appetite bird birds bread columba livia domestica common domestic pigeon fancy pigeons fauna feathers feeders feeding feral flock garbage greedy gregarious ground feeders iridescence iridescent pests pigeon pigeon pie pigeons plumage plumage varieties prolific rock pigeon scraps variations variety angles appearances architectural architecture blue box-like buildings business-district city city-scapes city-views color colour contemporary contrast contrasting distance distant distinctive elements exterior external glass gray grey heights high high-rise light linear lines modern office-buildings offices perspectives rectangles rectangular reflections reflective style views walls windows black & white greyscale monotone