Community & Business
15 November, 2023
Koalas on the move
A young male koala tagged at Yarranlea six months ago has now travelled more than 16 kilometres across open country and fragmented timber.
This surprising stamina and determination was revealed when USQ research fellow Damber Bista spoke at Landcare’s November meeting.
With assistance from Pittsworth Landcare and local landholders, a USQ team of scientists has put tracking collars on 16 male and 17 female koalas since April, mostly at Yarranlea, Kincora and Linthorpe.
The project was instigated by ARTC as part of its EIS process for the proposed Inland Rail corridor across the Central Downs.
The two-year-old male is the stand-out adventurer of the tracked koalas so far, although a four-year-old female has travelled 14 kilometres north from Yarranlea in one month.
Another two-year-old female has moved five kilometres from where she was collared.
Spring is the season when koalas are dispersing from their winter homes.
Males are looking for love, females for good habitat and one-year-olds are being given the heave-ho to leave home.
Mr Bista said the age and gender ratios of the 33 koalas studied indicate a stable population, with ages ranging from two to
15 years, teeth wear being the main guide.
Half of the animals with collars have been under six years of age.
Pittsworth koalas appear to have relatively less chlamydia than many coastal and hinterland populations, and the farmland ones less so than in the uplands.
One-third of the collars have already come off in the first few months.
This drop-off rate is expected as the collars are never put on tightly and they all have a ‘fuse’ link which breaks under pressure.
The collar sends up a locational signal every four hours.
It carries a solar panel to power the GPS device and has a back-up VHF capacity, enabling the collar to be found using an antenna if the signal fails.
Females are tagged on the right ear, males on the left.
Mr Bista said the adventurous two-year-old koala had spent a sedentary four months at Yarranlea (April, May, June and July) moving an average of 60 metres a day.
In August, he started training, averaging 120 metres a day, and by September he was moving an average of 500 metres a day.
Dispersal brings danger - cars, dogs, foxes - so in our fragmented landscape every single tree is important.
The USQ research has already shown some koalas are crossing 1.5 kilometres of bare ground during their travels.
- Alastair Silcock
