Returning a lost process by reintroducing a locally extinct digging marsupial.

Area of Science:

• Ecological Restoration
• Ecosystem Engineering
• Marsupial Ecology

Background:

• The eastern bettong (Bettongia gaimardi), a digging marsupial, was reintroduced to mainland Australia after a century-long absence.
• Temperate woodlands degraded by livestock grazing may benefit from the soil disturbance created by bettong digging.
• Understanding the bettong's digging capacity is crucial to assess its role as an ecosystem engineer and its potential for ecological restoration.

Purpose of the Study:

• To investigate the digging capacity of the eastern bettong.
• To compare the digging activity of bettongs with other extant fauna.
• To determine if bettongs qualify as ecosystem engineers capable of restoring ecological processes.

Main Methods:

• Quantified foraging pits created by eastern bettongs and other fauna in a reintroduced population.
• Estimated the volume of soil displaced by bettong digging (kg soil per ha per year).
• Analyzed the relationship between bettong digging activity and environmental factors (soil phosphorus, vegetation, grazing pressure).

Main Results:

• Eastern bettongs were frequent diggers, responsible for over 55% of observed foraging pits at densities of 0.3-0.4 animals/ha.
• An estimated 985 kg of soil per ha per year was dug by the bettong population.
• Bettong digging was influenced by soil phosphorus, Acacia spp. basal area, and reduced kangaroo grazing, and they uniquely dug in scalded areas.

Conclusions:

• Eastern bettongs exhibit significant digging capacity, exceeding that of other native and introduced species.
• Their unique ability to disturb diverse soil types, including scalds, highlights their potential as ecosystem engineers.
• Bettong reintroduction offers a promising strategy for enhancing soil processes and restoring degraded temperate woodlands.