The mysterious Spotted Green Pigeon and its relation to the Dodo and its kindred

摘要

BackgroundThe closely related and extinct Dodo (Raphus cucullatus) and Rodrigues Solitaire (Pezophaps solitaria), both in the subfamily Raphinae, are members of a clade of morphologically very diverse pigeons. Genetic analyses have revealed that the Nicobar Pigeon (Caloenas nicobarica) is the closest living relative of these birds, thereby highlighting their ancestors’ remarkable migration and morphological evolution. The Spotted Green Pigeon (Caloenas maculata) was described in 1783 and showed some similarities to the Nicobar Pigeon. Soon however the taxon fell into obscurity, as it was regarded as simply an abnormal form of the Nicobar Pigeon. The relationship between both taxa has occasionally been questioned, leading some ornithologists to suggest that the two may in fact be different taxa. Today only one of the original two specimens survives and nothing is known about the origin of the taxon. Due to its potential close relationship, the Spotted Green Pigeon may hold clues to the historical migration, isolation and morphological evolution of the Dodo and its kindred.