“Be careful what you wish for” also pertains to mouse plague, floods, & infestations of snakes & spiders
MELBOURNE, SYDNEY––What stops a mouse plague?
Driving 40,000 Australians from their homes in Victoria and New South Wales states, while filling many of those homes with spiders and snakes seeking high ground, the worst flooding in decades in late March 2021 might have caused many Aussies to recall the adage, attributed to Aesop, “Be careful what you wish for.”
Aesop, a Grecian slave and storyteller believed to have lived from 620 to 564 BCE, was renowned in part for his fable “Belling the cat,” spotlighting the cat/mouse predator/prey relationship.
But Aesop appears not to have been studied much in Australia in recent years.
Praying for “an almighty flood”
“Drought, fire, the Covid-19 pestilence, and an all-consuming plague of mice. Rural New South Wales has faced just about every Biblical challenge nature has to offer in the last few years,” observed Guardian correspondent Matilda Boseley on March 19, 2021, “but now it is praying for another––an almighty flood to drown the mice in their burrows and cleanse the blighted land of the rodents. Or some very heavy rain, at least.”
Record heavy rainfall began within days.
“Wet weather in northern New South Wales has given some landowners a reprieve from the mouse plague,” observed New Daily writers Leonie Thorne and Lucy Thackray five days later.
Commonwealth Scientific and Industrial Research Organisation [CSIRO] scientist Steve Henry warned Thorne and Thackray, however, that “It’s a bit tricky to know exactly what this rain will mean for mouse populations.
Mice likely to breed back to carrying capacity
“If it will be of a magnitude that will flood burrows out and force mice to seek shelter,” Henry said, “it could potentially kill a lot of mouse pups who were down the burrow. But in terms of killing large numbers of adult mice, that’s unknown.
“Potentially,” Henry theorized, “it might just get them to move somewhere that’s a bit drier and then [they will] move back into those areas that were so wet earlier.”
Agronomist Simon Logan of Walgett, New South Wales, called for “total inundation,” he told Thorne and Thackray.
“Otherwise,” Logan said, “there’s a chance there’ll be a few that survive,” to breed back up to the considerable carrying capacity of the habitat within a matter of weeks, if not days.
No mention of cats, foxes, & cane toads
Walgett agricultural services worker Enid Coupé, claiming to have removed 913 mice from her shed, called for intensive poisoning to follow up the mouse-killing effects of the flooding.
“Now’s the time to hit them hard and kill the mice that are left, so that we’re looking at being able to plant a crop that’s not going to get eaten overnight by thousands of mice,” Coupé opined to Thorne and Thackray.
Significantly, none of the experts mentioned cats, foxes, or cane toads, all of them accomplished mouse predators. Cane toads are also voracious predators of spiders and snakes. Ecological dogma in Australia, however, is that cats, foxes, and cane toads are all enemies of indigenous species––though they were introduced to help control mice, rats, rabbits, and sugar cane beetles, whom indigenous species had already proved unable either to control or compete with in human-modified habitat.
Big grain harvest brought mouse plague
CSIRO scientist Henry told The Guardian reporters that the mouse plague probably resulted from an unusually large grain harvest.
“They start breeding earlier,” Henry explained, “and because there’s lots of food and shelter in the system, they continue to breed from early spring right through into the autumn.
“Some farmers are giving up on summer crops,” Henry said, “because the mice have damaged them so severely that it’s essentially a total crop loss. Where farmers have managed to get the crops through to harvest, they’ve had their harvests rejected because it’s full of mouse poo.”.
“Mice get switched on”
The mid-March flooding killed enough mice that rural residents throughout Victoria and New South Wales complained about the stench of the corpses.
Henry, however, expressed skepticism that the rains had accomplished much beyond stimulating further mouse irruptions.
“We’ve had a run of dry years,” Henry said, “and [now] the drought has essentially broken, so the mice get switched on to that change in environmental conditions, and they start to breed.
“The farmers have had a good crop and that puts a lot of food into the system,” most of it still accessible to mice despite the few days of inundation. “So you’ve got favorable climatic conditions, favorable food in the system, lots of good shelter, and lots of moisture,” Henry repeated.
“We have great fun”
James Jackson, president of NSW Farmers, called for “urgent action from the state government, including emergency permission to use the pesticide zinc phosphide,” reported Nick Baker for Science News.
Even as a New South Wales Animal Justice Party motion to outlaw animal “crush videos” cleared the NSW upper house, parents proudly posted to social media videos and other documentation of the methods they and their children had devised to kill mice as entertainment.
“I’ve got a four- and a five-year-old,” Pip Goldsmith of Coonamble told Matilda Boseley of the The Guardian. “We have great fun engineering our traps with buckets and wine bottles. They’ve got very quick at catching and disposing of mice. It makes you proud and squeamish at the same time.”
Lisa Gore of Queensland boasted to Boseley about how many mice her 12-year-old son had trapped and killed.
Cat persecution preceded mouse plagues
Almost entirely overlooked, though, were the effects of intensive cat extermination campaigns undertaken in many of the exact same areas now suffering mouse plagues.
The Game & Feral Animal Control Act 2002 made feral cats legal targets for hunters throughout New South Wales.
When that and similar policy changes in other Australian states failed to arrest the ongoing decline of New South Wales native species, which hardly anyone denies is chiefly the result of human-induced habitat change, the Australian national government in July 2015 introduced a scheme to kill two million cats by 2020.
As that effort faltered, the New South Wales departments of Primary Industries, National Parks, Wildlife, and Local Land Services in August 2019 jointly committed $30 million over five years into developing more effective cat-killing methods.
Governments were warned
Then, following the devastating bushfires of 2019-2020, the governments of New South Wales, Victoria, and Queensland escalated poisoning campaigns against cats, rats, and foxes, in particular. This was said to be necessary to reduce predator pressure on native species who had suffered habitat losses.
The high mucky-mucks behind the cat purges were amply warned––if they had bothered to read relevant research.
Sophie Riley, a senior lecturer in the Faculty of Law at the University of Technology Sydney, on February 18, 2019 published an online review of The Changing Legal Status of Cats in Australia: From Friend of the Settlers, to Enemy of the Rabbit, and Now a Threat to Biodiversity and Biosecurity Risk, which pointed out that lethal methods of feral cat control overlook “non-lethal processes, such as trap-neuter-release,” and disregard the reasons why feral cats continue to thrive in Australia despite persecution.
Those reasons include irruptions of mice, rats, and rabbits.
“Weak scientific basis”
Just one day later, on February 19, 2019, biologists Tim S. Doherty, Don A. Driscoll, Dale G. Nimmo, Euan G. Ritchie, and Ricky‐John Spencer published “Conservation or politics? Australia’s target to kill 2 million cats,” in the journal Conservation Letters, the periodical of the Society for Conservation Biology.
“We argue that the well‐publicized [government] target to cull two million feral cats has a weak scientific basis,” the five scientists began, “because: (1) reliable estimates of Australia’s cat population size did not exist when the target was set; (2) it is extremely difficult to measure progress (numbers of cats killed) in an accurate, reliable way; and, most importantly, (3) the cull target is not explicitly linked to direct conservation outcomes (e.g., measured increases in threatened species populations).
“These limitations mean that the cull target fails to meet what would be considered best practice for pest management,” the five continued. “The focus on killing cats runs the risk of distracting attention away from other threats to biodiversity, most prominent of which is widespread, ongoing habitat loss.”
“When the cat is away, the mice will play”
The Latin phrase dum felis dormit, mus gaudet et exsi litantro meanwhile appears to be as little heeded Down Under as Aesop.
It means, “When the cat is away, the mice will play.”
This warning may not have been known to Pope Gregory IX (1145–1241), who initiated the century-plus of cat persecution in Europe that culminated in the Black Death.
Between 1346 and 1353, bubonic plague, spread by fleas infesting black rats, may have killed as many as 200 million people in Europe and Asia.
Learning spread slowly in the Middle Ages, so Queen Elizabeth I of Britain (1533–1603) may also have been ignorant of dum felis dormit, mus gaudet et exsi litantro. She included cat-burning as part of her coronation ceremonies, and passed the Witchcraft Act of 1563, making cat persecution British national policy.
After the Great Plague of London killed 75,000 people in 1665-1666, however, dum felis dormit, mus gaudet et exsi litantro in translation became one of the best-known phrases in the English language. It might even be known to some Australians.