© Andy ZakeliThe endangered bilby helps make the desert bloom.
Australia- Despite its diminutive size, the humble bilby can dig a desert back to life, according to research that reveals the marsupial's vital role in arid environments.

Alex James, a PhD student from the University of NSW, said the bilby's night-time foraging expeditions left the desert surface full of potholes, which made for ideal conditions for nutrient-rich "hot spots" to develop.

The potholes, the result of the bilby digging for food, are no deeper than 20 centimeters and about the size of a saucer. But Ms James found they played an important role in revegetation, with the depressions trapping seeds, plant matter and water.

"Soils in arid areas are very nutrient-poor, so any (plant) litter that gets trapped and decomposes increases the nutrients in the soil which benefits plant growth," she said, noting that bilby diggings contained up to twice the levels of nitrogen and carbon nutrients as undisturbed soil.

This process can transform patches of desert into a virtual nursery for seedlings, helping prevent soil erosion.

During her research at the fenced-off 60 square kilometres of the Arid Recovery Reserve near Roxby Downs in northern South Australia, Ms James found the burrowing bettong played a similar role to the bilby.

Ms James said the bilby and bettong were better for plant diversity than the destructive introduced rabbit, with a greater variety of plants found in their foraging areas.

Threatened by cats and foxes, the bilby has disappeared from much of central Australia and is considered endangered.