Gallicolumba - Systematics and Extinctions

Systematics and Extinctions

Trugon and Gallicolumba might be ranked as a (very small) subfamily, but the available data suggests that they are better considered part of a quite basal radiation of Columbidae which consists of many small and often bizarre lineages (e.g. Goura and Otidiphaps which are ecologically convergent to Galliformes, and maybe even the famous didines (Raphinae). Currently not quite 20 species of Gallicolumba are extant. Of the larger genera of Columbidae, Gallicolumba is the one most affected by extinction. 3-4 species have disappeared since the 18th century, and most of the remaining are decreasing in numbers, threatened with extinction or have lost subspecies due to habitat destruction, invasive species, or overhunting. In addition, there are several species never studied alive but known from subfossil bones. These became extinct during the human settlement of the Southern Pacific region (c. 3000 BC - 1400).

The bones of Gallicolumba are distinct enough to usually recognize this genus with ease. Still, the evolutionary affiliation of extinct species is often uncertain. A considerable number of recognizably distinct now-extinct Polynesian taxa used to inhabit the area where the white-headed lineage (G. jobiensis, G. erythroptera) and the Melanesian expansion that brought about G. sanctaecrucis and G. stairi (and possibly G. rubescens) would have met.