Ecologists were recently enthralled in a game of 'spot the quoll', as they flew over Western Australia's Wheatbelt on Badimia Country in search of eight missing Chuditch (Western Quoll).
A plane was deployed to assist the search party in their pursuit of the quolls that had fallen off ecologists' radar late last year, when they were released at Australian Wildlife Conservancy's (AWC) Mt Gibson Wildlife Sanctuary. The individuals were part of a significant mammal restoration project to return 10 locally extinct species to the 131,800-hectares conservation site. Chuditch was the final species in the ambitious project.
Cassandra Harvey/AWC Prior to release, several quolls were fitted with a VHF radio tracking collar to monitor their progress and transition. Using a specially equipped drone by Wildlife Drones, ecologists were able to track down eleven collared individuals in the ~70,000-hectare release area. However, eight quolls evaded the team, unable to be found via usual methods of radiotracking drone or on foot searching.
"We searched as high and low as we could using the drone, driving and walking across the property, but the quolls were nowhere to be found," said Dr Louis O'Neill, AWC Wildlife Ecologist. "We figured they had travelled well beyond the sanctuary's boundaries and our only option was to charter a plane and take the search well above ground."
Over two days, ecologists flew across 1,266 km (covering roughly 450,000 hectares) of the Wheatbelt. The search effort included all of Mt Gibson as well as neighbouring properties; Charles Darwin Reserve owned by Bush Heritage Australia, Biluny Wells Nature Reserve jointly managed by Badimia Bandi Barna Aboriginal Corporation and WA's Department and Biodiversity, Conservation and Attractions (DBCA), and Ninghan Station Indigenous Protected Area. Aerial radiotracking equipment was kindly loaned by DBCA.
Louis O'Neill/AWC In the end, the search was well worth the effort, with four of the eight missing quolls tracked down in areas only accessible to the team by plane.
"Eager little explorers, the quolls travelled further than we imagined they would," added Dr O'Neill. "One individual managed to move 50 km south west of the sanctuary, while the others clocked 27, 28 and 30 km."
Unfortunately, two of the quolls had died, perhaps shortly after their release. There are many risks when native animals are translocated, particularly when they are released into areas where feral cats and foxes are present, as they are outside the fenced exclosure at Mt Gibson.
Cassandra Harvey/AWC Swabs of the bodies and collars were sent to a lab in Perth for analysis. No DNA from cats or foxes was found on the swabs, so it is possible that these animals died of natural causes. Nevertheless, the team at Mt Gibson maintains a very active feral animal control program, including regular baiting for cats and foxes, to try and give reintroduced animals the best possible shot at establishing in their new environment.
The other two were alive and well, found to the far south of the property. 'Arasari', a male quoll from the Taronga Zoo captive breeding program in Dubbo, was found living in babbler nest near Mt Gibson's southern boundary. The team managed to trap him within a couple of days and bring him back to the release area on Mt Gibson, where he has remained ever since.
AWC 'Kakapo', a female from Taronga, was found on neighouring Biluny Wells Nature Reserve. She proved much more difficult to trap but the team persevered and she was finally caught nearly six weeks after the flight and brought back to Mt Gibson, to contribute to the establishment of the population. She too has remained on the property since repatriation.
Mt Gibson ecologists are currently monitoring the four remaining radio-collared individuals, all of which are being regularly detected on the property and seem settled into their new home.
Collared quolls will continue to be monitored until their collars either fall off or are removed towards the end of the expected battery life. Eight other quolls, recognised by their unique spot patterns, have also been detected on cameras we have deployed across the release area, including six born on Mt Gibson after the start of the reintroduction. These regular detections of so many different individuals indicate that the translocation is going well so far.
