Giant lizards called heath goannas could save Australian sheep farmers millions of dollars a year by keeping blowfly numbers down—and must be prioritized in conservation schemes to boost native wildlife, say researchers.

A study led by the University of Cambridge has found that heath goannas—a species of giant, scavenging lizard—act as natural cleanup crews by clearing maggot-ridden animal carcasses from the landscape.

This reduces the emergence of blowflies, which attack sheep by laying eggs on their backsides that hatch into flesh-eating maggots. The disease, known as “fly strike,” costs the Australian sheep farming industry an estimated $280 million a year.

This study was carried out at 18 sites across the Marna Banggara Rewilding Project area on Australia’s southern Yorke Peninsula, where over 90% of the native mammals are now extinct. The work is published in the journal Ecology and Evolution.

The study found that heath goannas perform a superior blowfly control service to introduced European mammals, including red foxes and cats, which are displacing them.

The researchers say that boosting populations of native large reptiles like heath goannas is vital in restoring Australia’s ecosystem and the services it supports.

“We found that Australia’s native scavengers like heath goannas are much more effective in removing blowflies from the landscape than invasive scavengers like European foxes and cats,” said Tom Jameson, a Ph.D. researcher in the University of Cambridge’s Department of Zoology and first author of the report.

High densities of blow flies put sheep at risk of fly strike, a disease where blowfly maggots burrow into the sheep’s flesh and start to eat it alive, causing painful wounds. This affects the market value of the sheep, reduces breeding success and often results in death.

“Blowflies are a massive problem for the Australian sheep farming industry. They cause a horrible disease that is expensive for farmers to manage and a real animal welfare problem for sheep,” said Jameson.

This is the first study to show the importance of large reptiles as scavengers.

To get these results, Jameson compared the scavenging activity of different animals in a region of southern Australia. He left hundreds of dead rats at feeding stations, with camera traps, across the landscape. He returned after five days to see whether the rats had been eaten, and to count the number of blowfly maggots left on any remaining carcasses. Camera trap footage revealed which scavenging animal had found the rat, and how quickly.

Native Australian scavengers ate more of the dead rats, and with them the flesh-eating maggots, than scavengers introduced from Europe.

“It was disgusting—we were counting maggots. After five days, we’d find over 1,000 maggots in one rat if a scavenger hadn’t found it. Those maggots produce blowflies that can spread up to 20 kilometers in a week, putting local sheep flocks at risk of fly strike,” said Jameson.

In natural situations, any dead animal in the landscape will fill with blowfly maggots very quickly.

“The results suggest that conservation work in southern Australia to remove invasive species should also focus on boosting the population of heath goannas and other native species because they’re really important for the wider ecosystem,” said Jameson. “As well as benefiting native wildlife, this will have knock-on benefits for local agricultural industry, and also attract more wildlife tourism.”

Marna Banggara, supported by Narungga traditional owners, is an ambitious rewilding project that aims to restore ecosystem health in the region by reintroducing missing native Australian species.

Eighteenth-century European settlers to Australia brought with them red foxes for hunting, and cats as pets. Australia’s native wildlife—including many scavengers—has since been decimated by them.

The heath goanna is an endangered species of giant lizard native to the heathlands of southern Australia that can grow up to a meter and a half in length. It feeds on the dead carcasses of other animals, as well as catching live animals.

Reptiles like the heath goanna are the largest remaining native land scavengers in much of Australia today.

A novel 256-element wirelessly powered transceiver array for non-line-of-sight 5G communication, featuring efficient wireless power transmission and high-power conversion efficiency, has been designed by scientists at Tokyo Tech.

The innovative design can enhance the 5G network coverage even to places with link blockage, improving flexibility and coverage area, and potentially making high-speed, low-latency communication more accessible.

Millimeter wave 5G communication, which uses extremely high-frequency radio signals (24 to 100 GHz), is a promising technology for next-generation wireless communication, exhibiting high speed, low latency, and large network capacity.

However, current 5G networks face two key challenges. The first one is the low signal-to-noise ratio (SNR). A high SNR is crucial for good communication. Another challenge is link blockage, which refers to the disruption in signal between transmitter and receiver due to obstacles such as buildings.

Beamforming is a key technique for long-distance communication using millimeter waves which improves SNR. This technique uses an array of sensors to focus radio signals into a narrow beam in a specific direction, akin to focusing a flashlight beam on a single point. However, it is limited to line-of-sight communication, where transmitters and receivers must be in a straight line, and the received signal can become degraded due to obstacles.

Furthermore, concrete and modern glass materials can cause high propagation losses. Hence, there is an urgent need for a non-line-of-sight (NLoS) relay system to extend the 5G network coverage, especially indoors.

To address these issues, a team of researchers led by Associate Professor Atsushi Shirane from the Laboratory for Future Interdisciplinary Research of Science and Technology at Tokyo Institute of Technology(Tokyo Tech) designed a novel wirelessly powered relay transceiver for 28 GHz millimeter-wave 5G communication. Their paper is published in the journal IEEE Microwave and Wireless Technology Letters.

Explaining the motivation behind their study, Shirane says, “Previously, for NLoS communication, two types of 5G relays have been explored: an active type and a wireless-powered type. While the active relay can maintain a good SNR even with few rectifier arrays, it has high power consumption.

“The wirelessly powered type does not require a dedicated power supply but needs many rectifier arrays to maintain SNR due to low conversion gain and uses CMOS diodes with lower than ten percent power conversion efficiency. Our design addresses their issues while using commercially available semiconductor integrated circuits (ICs).”

The proposed transceiver consists of 256 rectifier arrays with 24 GHz wireless power transfer (WPT). These arrays consist of discrete ICs, including gallium arsenide diodes, and baluns, which interface between balanced and unbalanced (bal–un) signal lines, DPDT switches, and digital ICs.

Notably, the transceiver is capable of simultaneous data and power transmission, converting 24 GHz WPT signal to direct current (DC) and facilitating 28 GHz bi-directional transmission and reception at the same time.

The 24 GHz signal is received at each rectifier individually, while the 28 GHz signal is transmitted and received using beamforming. Both signals can be received from the same or different directions and the 28 GHz signal can be transmitted either with retro-reflecting with the 24 GHz pilot signal or in any direction.

Testing revealed that the proposed transceiver can achieve a power conversion efficiency of 54% and a conversion gain of –19 decibels, higher than conventional transceivers while maintaining SNR over long distances. Additionally, it achieves about 56 milliwatts of power generation which can be increased even further by increasing the number of arrays. This can also improve the resolution of the transmission and reception beams.

“The proposed transceiver can contribute to the deployment of the millimeter-wave 5G network even to places where the link is blocked, improving installation flexibility and coverage area,” said Shirane.