 Significant mammals endemic to forests in the bioregion include various species of glider , such as Sugar Gliders ( Petaurus breviceps ) , Feathertail Gliders ( Acrobates pygmaeus ) and Squirrel Gliders ( Petaurus <unk> ) as well as Koalas ( Phascolarctos cinereus ) A wide variety of birdlife makes its home in wetlands in the Riverina , including many migratory species . Competition from introduced species and the effect of clearing , grazing and pasture improvement has led to a decline in the diversity of native flora and fauna in the area . 
