PASSERIFORMES: Petroicidae
Eopsaltria georgiana
The White-breasted Robin is thought to have originated from the Eastern Yellow Robin but when isolated in Western Australia by dryer conditions it evolved and lost its yellow pigmentation.
The Western Yellow Robin is thought to have also originated from the Eastern Yellow Robin at a more recent time when a moister climate again allowed a vegetation bridge between east and west Australia. Which has again gone isolating both species in the West.