Study shows bleak outlook for koalas in CQ without intervention
Central Queensland’s endangered koala population is facing a dire future if nothing is done to prevent the number of animals being killed by vehicles.
That’s according to CQUniversity and Griffith University koala researchers who have released findings from two separate studies focused on a stretch of the Peak Downs Highway, between Mackay and Nebo in Queensland.
Lead researcher CQUniversity’s Dr Rolf Schlagloth said Koala Research-CQ and its collaborators have analysed koala roadkill data spanning nearly a decade, and the outcomes aren’t good.
Over this 51km section of highway, 145 koalas were struck by vehicles in 2023 (data range to November 25), with 83 per cent of the koalas dying as a result. These koalas were otherwise in good health.
In comparison, 365 koalas in the entire South East Queensland region are sent into care due to vehicle collision each year.
“There are horrendous numbers of koalas getting hit and killed by vehicles every year on this relatively short stretch of road, with no reduction in sight,” Dr Schlagloth said.
“We’ve found that because of the amount and the mostly uniform distribution of good quality habitat, koalas are unfortunately killed nearly anywhere along this highway.
“Driver visibility is also a contributing factor. We know that the better or greater the visibility a driver has, the less likely it is for a koala vehicle collision to occur.”
Separating koalas and vehicles is difficult on the existing highway, but researchers believe future avoidance of high-quality koala habitat for highway infrastructure, in addition to constructing or retrofitting protective or diversionary infrastructure – which has already been started by the managing authority in several locations – could help reduce roadkill.
However, initial attempts to separate traffic and wildlife via retrofitted bridges are yet to bring good news to researchers – and the koala population.
“We have monitored three bridges that had been retrofitted with short sections of wildlife exclusion/diversion fencing to encourage koalas (and other wildlife) to pass underneath the road rather than taking the risk of crossing the road proper,” Dr Schlagloth said.
“While rare usage of other, similar structures by koalas has been reported, unfortunately, despite monitoring these underpasses, we have not found any evidence of koalas having used them to get to the other side of the road, while we do have evidence of koalas having crossed the highway successfully and unsuccessfully near those underpasses.”
Researchers said there was evidence that wildlife exclusion fencing may be assisting in keeping koalas away from particular stretches of road (three study sites), but it did not facilitate koala crossings under the highway.
“Maybe koalas will use underpasses over time, or maybe more and longer fencing would be of benefit – further research here is paramount.
“Improving driver attention and their awareness of the potential for koalas to be on the road could also go a long way to reducing the deaths.
“This is most definitely not a sustainable situation for this endangered species.”
Dr Flavia Santamaria, a co-author of these studies stressed: “The Central Queensland koala population is also under threat from diseases like Chlamydia and retrovirus, and opportunities for specialist treatment for injured or sick koalas are not readily available in the region, making it even more important to reduce the number of koala vehicle collisions.”
Griffith University researcher Dr Douglas Kerlin believed governments needed to step in to protect this koala population.
“Unfortunately, these koalas are not receiving enough protection from the Government. In Queensland, koalas are listed as ‘endangered’ under the Nature Conservation Act, but policies enacted by the State Government are currently focused on populations in South East Queensland, while koalas in places like Central Queensland are largely ignored.
“Similarly, much of the traffic along this highway is supplying mining activities in the Bowen Basin, but the Federal Government Environmental Protection and Biodiversity Conservation Act approvals process has only focused on the direct impacts of industry on koalas, and has largely ignored the wider indirect impacts, such as increased traffic volumes on transport infrastructure corridors.”
Dr Schlagloth also commended the tireless efforts of former citizen scientist, now CQUniversity Honours student, Charley Geddes who dedicated her time to monitoring the stretch of road all hours of the day or night to pick up dead koalas.
“Our understanding of this koala population is down to her dedication … given the level of population attrition caused by the road, this could be a koala population of national significance, one we would know very little about if it wasn’t for her work.”
The latest studies were funded by the Department of Transport and Main Roads, and researchers believe further funding needs to be allocated to conserving this koala population.
Transcript
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Look we released two uh studies simultaneously um they were all connected to Transport and Main Roads at the Peak Downs Highway that runs from Mackay to Nebo and beyond uh it's a very busy highway it services the mining in in the west and we have sometimes up to 120 koalas being killed on that highway alone these are the ones that we know of some get injured as well and the um prognosis for the injured one is not very good 93% of them die or have to be put down so we really want to raise that profile of the koala population there because it's vitally important um the koalas in central Queensland are moving more to the towards the coast because of climatic changes droughts and so forth and um this is a population of significance for the whole of Australia basically we we've done initial research and we looked at some uh underpasses and because the fencing is very short the koalas have not yet used it if you look at areas in Southeast Queensland where there's a lot of investment for koala protection the fences go for tens of kilometres we have a couple hundred metres either side koalas still avoid the fencing and get bowled over on the highway we do need to do something like that we need to look at the health of the animals population size uh the condition reproduction survival and the like um it's an important population I mean the sheer number is just mind boggling right uh but because we don't know much about the population how many they are where exactly they are how widespread they are how healthy they are uh we don't know what the impact is but you know 120 whether it's a huge impact or a medium impact on the population it's too much you you definitely need to separate koalas and the highway and I have to say the landholders up there are very uh positive supportive uh they're big landholders have big properties so um you know we would like to work with them and I'm sure the government would like to work with them in um you know erecting more fencing uh encourage them under the underpasses because we can't sustain 120 kills a year it's not sustainable at all never is and never will
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