Victoria’s forests have an unlikely fire warden: the superb lyrebird.
“Lyrebirds are reducing the chance of fires occurring in the areas where they forage … and unburnt patches within large wildfires are really important sites for animals to survive.”
New research has revealed the iconic songbird reduces the risk of bushfire by spreading dry leaf litter and digging safe havens that help other species survive fires.
The lyrebird’s foraging reduces forest fuel loads, which in turn can reduce the risk of life-threatening fires, researchers from La Trobe University have found.
With feet like garden rakes, and an appetite for worms and bugs that live in the soil, lyrebirds sift the forest floor, burying the leaf and other forest ltter, speeding up leaf decomposition, and reducing the amount of fuel for bushfires.
Their foraging was also found to inhibit the growth of ferns, grasses and other plants which would otherwise contribute more potential bushfire fuels.
The research, an honours project for student Daniel Nugent, quantifies the lyrebird’s role in forest litter reduction.
Conducted in burnt and unburnt sites in the footprint of Black Saturday’s two most devastating blazes, it showed that lyrebirds reduced forest litter by a massive 1.66 tonnes per hectare over a nine-month period.
Researchers produced these measurements by comparing the amount of litter in unfenced plots of the forest, with neighbouring plots that had been fenced off.
“Lyrebird foraging areas may therefore suppress the horizontal and vertical spread of fire, limiting the extent and severity of fire events. Our modelling suggests that the reduction in litter fuel loads brought about by lyrebird foraging has the potential to result in markedly subdued fire behaviour relative to that predicted in the absence of lyrebirds,” the report said.
“The loss of lyrebirds from forests adjacent and within urban areas could result in higher fuel loads and an increased likelihood of wildfires threatening human life,” said the report, published in the CSIRO’s journal Wildlife Research.
Steve Leonard, research fellow in the Department of Ecology, Environment and Evolution at La Trobe University, said lyrebirds performed their protective role as they searched for food.
“They forage like chickens, they’ve got big feet with really long toes so they’ve basically got rakes for feet. They rake through the litter looking for worms and little bugs, stuff to eat. They’re digging through that humus and litter layer looking for little invertebrates and whatever they can find,” he said.
“Through that process they reduce the litter fuel load by, on average, 25 per cent, or about 1.6 tonnes per hectare. And we put those figures into a fire behaviour model and found that that level of fuel reduction is enough [that] in low fire-danger weather conditions it excludes fire, fire’s not possible under low to moderate conditions. But even in more extreme conditions the fire behaviour will be more moderate, [with] lower rates of spread, lower flame height, so a less intense fire,” he said.
“Our conclusion is that lyrebirds are reducing the chance of fires occurring in the areas where they forage and the ecological significance of that is that unburnt patches within large wildfires are really important sites for animals to survive post-fire,” Dr Leonard said.
Alex Maisey, convener of the Sherbrooke Lyrebird Survey Group, welcomed the research.
“It really shows that it’s an important species to maintain through predator control of the fox, even deer control, for maintaining the habitat in those key areas where the lyrebirds breed,” he said.