Color of orbital skin varies considerably between columbiform species (Goodwin 1983, Gibbs & Barnes 2000).
Irises of columbiform species differ even more than those of domestic pigeons, e.
ceres, crests), colors of soft parts, sexual dichromatism, flight abilities, flight displays and elaborate vocalizations in columbiform species that parallel analogous traits in the original Darwin's pigeons and other domestic breeds of the Rock Rove (Table 1).
Whereas Darwin (1868) considered the blue-bar of the extant Rock Dove the older character state and the checker of some conspecific individuals the derived state, Whitman (1919) argued that in fact checker probably occurred in the ancestral columbiform and that the expression of this pattern is somehow masked in most species during evolution.
Possibly the genes controlling many of the color patterns, visual displays and vocal attributes shared by domestic pigeons and various extant columbiform species were present in the proto-columbiform, and due to mutation and natural selection appear as complete complexes, not de novo, but as a result of suppression and expression of single regulatory genes.
Character states shared by domestic pigeon breeds and extant columbiform species.
Columbiforms may be referred to as pigeons or doves, and the two terms are often interchangeable.
Columbiforms may be found on all continents except for Antarctica (Goodwin 1983, Gibbs & Barnes 2000).