Avian clutch size of increasing clutch size with increasing latitude. The proximate and ultimate causes for this pattern have been a subject of intense debate involving the ideas of group and individual selection. David Lack observed a direct relationship between latitude and avian clutch size. Birds near the equator laid approximately half as many eggs as those that resided in northern temperate habitats. He observed an increasing clutch-size from the equator towards the poles (something he referred to as the “latitude trend”) for many passerine (perching) birds, near-passerine (tree-dwelling) birds and in various other groups: Strigiformes, Falconiformes, Ciconiiformes, Laridae, Ralliformes, Galliformes, Podicipedifomes, and
Birds Mosaic (Jerusalem) The mosaic includes many figures of birds, which are inscribed in 39 round medallions formed from images of grape vines. The mosaic is bounded by a colorful "braided" frame. This is a symmetric mosaic, where elements on the right side are "reflected" to the left, so every bird on the right side has a twin on the left side, except those on the central axis. Therefore, most of the birds are facing the central axis. The birds lack "depth " and perspective: while Greek and Roman mosaic art involved perspective and three-dimensional depiction, Byzantine mosaic art which developed in Israel