Community
25 April, 2024
Could rare footage help to solve rodent issue?
RARE footage of an encounter between two invasive species has prompted one south west conservationist to ponder an alternative to the destructive efforts to combat rat and mice populations.
Laang’s Lisette Mill, owner and operator of Biodiversity Innovation Australia, recently captured rare footage of an encounter between a Black Rat and House Mouse this month which she believes could provide a solution for the out-of-control population of both species.
Ms Mill, who has been operating cameras for 15 years in the hopes of contributing to Australian biodiversity knowledge, said she had recorded an instance of muricide.
“Muricide is the instinct of rats to hunt, kill, and eat mice,” she said.
“It is rarely filmed in the wild in Australia.”
After seeing the footage, Ms Mill said she believed the predatory behaviour could hold the solution to controlling the rapidly expanding populations of both invasive species, through a “trojan horse” requiring little more than the natural selection wildlife confront each day.
“What this film shows is a possibility of how the instinctive behaviour of Black Rats might be harnessed using another pest (House mice) to deliver a fatal blow to both,” she said.
“Rats hunt mice instinctively, actively, and voraciously – and these pests are seldom found in isolation of each other.
“What if mice could be fed something that doesn’t kill them but will render infertile any pest rat that kills and eats the mouse?
“Pest mice as the Trojan horse to deliver generational death to pest rats, such as a pest rodent specific control that doesn't act on off-target natives.”
Ms Mill said both species had been responsible for untold damages since being introduced some 200 years ago.
“The damage to all layers of ecology including plants they have wrought is immense,” she said.
“They spread disease, destroy agricultural productivity, kill biodiversity, and win against most of our methods to control them - every day.”
Attempts to control invasive mice and rat populations since they were introduced have created a “wicked problem”, according to Ms Mill, as methods regularly resulted in unintended harm to native species.
Poison is among the most common methods of attempts to control population growth among rats and mice, however this can cause unintended harm to native predators which benefit Australia’s ecosystem: such as Barn Owls, Powerful Owls, Kites and Hawks, and their chicks.
The same rational also applies to the use of traps designed to kill, which cannot differentiate an invasive pest from similarly-sized native wildlife.
“Many of the poisons used to kill rats and mice move through the food chain and end up concentrated in the tissues of beneficial native species that hunt rats and mice,” Ms Mill said.
“This is an issue both for conservation but also the social license of the retailers that sell those poisons; every supermarket, ag supply and hardware chain in Australia could refuse to stock the generation of rodenticides that harm off-target species.
“Many of the mechanical tools we use to control pest rats and mice in Australia are very old tech which also kills similar native creatures such as Swamp Rats, Bush Rats, Heath Mice, Hopping Mice, Antechinus, and even threatened Southern Brown Bandicoots.
“No mechanical rat or mouse trap that kills the creature that triggers it has AI recognition to allow it to decide not to kill a non-target species.”
Ms Mill said she was interested in holding further discussion with agencies such as the Invasive Species Council, Centre for Invasive Species Solutions, Department of Agriculture, Fisheries and Forestry to discuss research possibilities.
“I want to be involved, and the ball is in their court now,” she said.