The So'a Basin (Flores) contains the earliest evidence for hominins in Wallacea.
We identified six bird species from Early/Middle Pleistocene deposits at So'a.
Two taxa, a swan Cygnus sp. and an eagle owl Bubo sp., no longer occur on Flores.
The avian assemblage indicates an open lake environment and forests at a distance.
An open environment in the So'a Basin may have facilitated hominin dispersal.