Wily WomBot used to snoop on wombat burrows

Wombats, the powerful and stubby-bodied Australian marsupials, reside and sleep in burrows, switching between different burrows every four to ten days. Parasitic mites that cause sarcoptic mange – a serious disease affecting wombats – are thought to be transmitted when wombats occupy each other’s burrows. However, it has not been understood whether the conditions within burrows promote this transmission.

The WomBot is a highly specialised tool developed to investigate environmental conditions within wombat burrows. It is a remotely operated device which trundles on tracks at up to 0.15m/s and can climb slopes of up to 22°. It contains a set of fixed sensors for measuring the humidity and temperature; has cameras facing forwards and backwards to help researchers visualise the environment, and a gripper sticking out of the front that can be used to contain additional environmental sensors. It is 30cm long and weighs just 2kg.

“Wombat burrows are challenging to study as they are narrow, muddy, can be dozens of metres long and contain steep sections and sharp turns,” said Dr Robert Ross, co-author of the SN Applied Sciences study. “WomBot allows us to enter and explore these burrows without destroying them or using expensive ground-penetrating radar. This can help us better understand the environmental conditions within burrows that may facilitate sarcoptic mange transmission.”

Ross and his colleagues used WomBot to investigate 30 wombat burrows in Tasmania during September 2020. They found an average temperature of 15°C inside the burrows, with minimal change over a 24-hour period (compared with three to 15°C outside the burrow), and average relative humidity of 85 per cent (compared with 70 to 95 per cent outside the burrow).

Previous research suggests that promoting the maximum survival of scabies mites are temperatures around 10°C and relative humidity between 75 and 97 per cent: similar to the conditions measured inside the wombat burrows. The authors estimate that female mites could survive for between nine and ten days at the entrance to a wombat burrow and between 16 and 18 days inside a burrow, offering them the opportunity to infect unsuspecting wombats. However, they acknowledge that the conditions observed within the limits of their study may not be representative of conditions inside all these burrows throughout the year.

“Our findings indicate that the environmental conditions within wombat burrows may facilitate sarcoptic mange transmission by promoting mite survival,” Ross continued. “WomBot could potentially be used to help reduce the spread of sarcoptic mange by delivering insecticide or ensuring burrows are empty before being temporarily heated in order to eradicate mites.”

Future research, Ross suggests, could involve using data collected by WomBot to generate 3D models of burrows and to collect samples from burrows to study mite prevalence.

In further wombat-related technology news, scientists from the University of Adelaide in 2016 demonstrated it is possible to map wombat burrows – often built beneath many layers of hard limestone – using ground-penetrating radar.

Wombats are known as scientific curiosities due to their unique cube-shaped faeces. In 2018, US scientists investigated the development of faeces inside wombat intestines. They found that the faeces solidify in the final section of the intestine; as the walls of this part of the intestine do not stretch evenly, it deforms and moulds faeces into regular blocks.