The population of Eastern Bettongs released ‘beyond the fence’ in the Lower Cotter Catchment are no more, but researchers say the trial has provided valuable information.
According to Dr Will Batson, manager of Mulligan’s Flat Woodland Sanctuary, as of March last year, the 67 bettongs released through the program had perished primarily due to fox predation.
“There was always a realistic expectation that this was a risky trial,” Dr Batson said. “What we didn’t know was the amount of resources that would need to be provided to maintain a viable population.”
The population of bettongs were intensely monitored throughout the trial with all radio collared. Dr Batson said they were regularly trapped to assess their health and breeding status.
In terms of positives for the trial, he said “we had adult bettongs survive over 18 months, long enough for females to produce four young”. Bettongs generally have a lifespan of five years in the wild.
However, while Dr Batson said all the females were producing young, “what we didn’t find was those young moving through to adulthood”.
Despite the result of the trial, he said they learnt some valuable information. They identified the times of year where there was an increased risk of predation, while “the larger the bettong, the better their survival chances”.
Dr Batson said there are still viable populations of bettongs at Mulligan’s Flat and Tidbinbilla (within predator-proof fencing), with the Lower Cotter trial only possible because of the success of those populations.
While some have been critical of the trial, Dr Batson said it is important to push the science to re-establish species rather than just accept the current situation.
He said the long term goal is still to establish the species outside fenced reserves but this could be up to 20 years away.