Non-invasive mapping of critically endangered northern hairy-nosed wombat (Lasiorhinus krefftii) burrows using ground-penetrating radar: a case study at Richard Underwood Nature Refuge

The northern hairy-nosed wombat (NHW) (Lasiorhinus krefftii) is a critically endangered marsupial, reduced to a single population at Epping Forest National Park (EFNP) by the early 1920s. Two additional populations were established through translocations, including Richard Underwood Nature Refuge (RUNR) in 2009 and Powrunna State Forest in 2024. Because NHW are fossorial, soil suitability for burrow construction is critical for selecting future sites. However, little is known about how burrow architecture varies in different environments. This study assessed whether recent advancements in ground penetrating radar (GPR) technology, more sophisticated than those used in previous studies, could provide detailed, non-invasive mapping of NHW burrows and compare burrow depths among populations. Despite a limited sample size (n = 5), advanced GPR showed that burrows at RUNR were shallower in both maximum and mean depth than were those at EFNP. This variation is likely due to the loamier soils at RUNR, which offer greater structural integrity, thereby reducing the need for deeper excavation, as is required in the sandier soils of the EFNP. These findings inform both the selection of future translocation sites and the design of pre-dug starter burrows essential to NHW reintroductions.