Bilbies are vital ecosystem engineers that dig pits while foraging that become fertile patches where native Australian fauna seeds are provided extra fertilization to germinate in a difficult environment.
While they are a source of food for a number of predators, both native and introduced, the most important role played by the bilby is that of an ecosystem engineer. Ecosystem engineers are organisms that modify, maintain, create, or destroy structure within the physical environment.
As bilbies forage for bulbs, seeds, and insects, they dig pits up to 25 centimeters deep that are then abandoned. These pits become areas where seeds, water, and other organic matter settle and begin to decompose. Bilby pits become fertile patches in the Australian desert where some seeds are provided the extra fertilization to germinate in an otherwise extremely difficult environment.
Studies compared environments without bilbies and a similar, native fossorial group, bettongs (Bettongia), to those where these two native species are present. It was concluded that environments without these native, fossorial animals suffered from devastating losses of native Australian fauna despite the presence of rabbits, which also dig burrows.