New research has revealed that vulnerable bilbies are important for whole ecosystems of smaller animals in the West Kimberley region.
During his Murdoch University PhD field work, Dr Stuart Dawson mounted camera traps next to the burrows of bilbies to monitor their comings and goings. The images from these cameras revealed a huge range of unexpected visitors to bilby burrows, in addition to the bilbies themselves.
“Bilbies are master engineers, capable of excavating multiple deep burrows within hours,” Dr Dawson said.
“This research highlights, and builds on, previous research that shows how important burrowing species can be for other animals.”
Biodiverse communities
Through cameras monitoring more than 100 burrows over three years in the West Kimberley, Dr Dawson and his colleagues have built a picture of the biodiverse communities using bilby burrows to survive in this harsh landscape.
More than 45 species of mammals, birds and reptiles were recorded either in the burrow or at its entrance.
“While we couldn’t record why each species used the burrows, the diversity of species we captured is profound,” Dr Dawson said.
“Our results suggested that these small to medium-sized animals captured on camera were taking advantage of the shade, cool loose soil, leaf litter and insects attracted to the burrow”.
It was apparent that bilbies are inadvertently providing benefits for a broader community. This was particularly evident after fire had swept through the area.
Bilbies were once found across 70 per cent of mainland Australia but today are now restricted to less than 20 per cent of their former range.
Dr Dawson warned this research showed that further decline in these iconic animals could have a profound impact on whole animal communities.
“This research highlights the broad-ranging benefits of digging mammals in Australia,” he said.
“The positive impact of digging mammals on nutrient cycling and water penetration is well known, but we are gaining a greater appreciation of the plethora of species that use burrows as well.
“While many of the species that we recorded using burrows were not of any significant conservation concern, a reduction in the abundance of burrows adds to existing pressures from agriculture, habitat fragmentation, drought and invasive species. In short, much of northern Australia is threatened by thousands of small cuts. Losing an important ecosystem engineer like the bilby would have cascading impacts on the landscape.”
This research paper – An outback oasis: the ecological importance of bilby burrows was published in the Journal of Zoology.