21 July 2022

Canberra faces rabbit plague if we don't develop new virus, experts say

| James Coleman
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Rabbit

Rabbits are beginning to outpace the effects of the latest virus. Photo: Dylan Calluy.

They may be cute and cuddly bundles of joy, but the truth is – left unchecked – rabbits are a scourge.

A double whammy of wet weather and a waning virus means there are even more of them hopping around the city and Lake Burley Griffin than usual. The looming spring – the official start of breeding season – will only make things worse.

The ACT Environment, Planning and Sustainable Development Directorate says rabbits alone have contributed to the extinction of many native plant and animal species.

Rabbits compete with livestock for pasture and kill young trees and shrubs by stripping them of bark. If left uncontrolled, rabbits will invade suburban gardens and cause even more damage to the environment and private property.

Research fellow and associate professor at the Australian National University (ANU), Richard Thackway, has dealt with rabbits his entire life, from shooting them on the farm to studying their growth in the ACT’s south. He says the impact of rabbits can be “absolutely horrendous”.

READ ALSO Pet rabbit deaths spark warning of calicivirus spread in Canberra

“Particularly in the sandy soils, rabbits burrow and eat every piece of vegetation on the landscape so the wind erosion just lifts away the soil. They destroy farmland.”

Richard says governments, industry experts and individuals have “tried their darndest” to get rid of the rascally rabbits for years with mixed success.

“We’ve tried throwing poisonous gases down the burrows, ripping their burrows open with bulldozers, and viruses,” he says.

“The latter works for a little while but the virus keeps mutating.”

Walking by Lake Burley Griffin and blossom trees.

Humans aren’t alone at Lake Burley Griffin. Photo: Michelle Kroll.

A new strain of calicivirus was released into two populations of pest rabbits in the ACT in March 2017 as part of a national rollout. This followed a largely unsuccessful bout in 2007 and built on an integrated rabbit control program introduced in 2009.

At first, the haemorrhagic virus crashed the local numbers. But Richard says like all viruses, it’s weakening.

Then there’s the weather. Like mice and rats, rabbits explode when there is plenty of food to be found. And thanks to at least two wetter-than-usual years in Canberra, there is a veritable feast of greenery.

The situation reached fever pitch in December 2021 when the ACT Government brought in professional shooters to rein in numbers near Parliament House.

Rabbits were first introduced to Australia in 1859 so the landed gentry could enjoy a spot of hunting. Initially, they struggled to get off the ground due the large number of native predators.

Richard Thackway

Richard Thackway has looked into Australia’s rabbit problem for decades. Photo: ANU.

“But acclimatisation societies were brought in because people seemed hell-bent on the fact we must have rabbits for hunting,” Richard says.

“And so we killed many of these native predators.”

In the right conditions, rabbits can have as many as seven litters a year with up to 12 babies at a time. These babies can begin reproducing as little as four months later.

With predators out of the way, rabbit numbers hit 600 million within 70 years. Stoats and ferrets were brought in to restore order and in turn, their numbers spiralled out of control. So foxes were introduced to help the native dingoes keep on top of all three species.

“We stuffed it up completely,” Richard says.

READ ALSO Shooters called in to control booming rabbit population

Andreas Glanznig from the Centre for Invasive Species Solutions, based at the University of Canberra, has championed a long-term rabbit bio-control pipeline strategy since 2012. He says the initial release of the myxomatosis virus in 1950 is still thought to be killing almost half of all rabbits but effectiveness typically begins to wane after 10 to 15 years.

“What we’re beginning to see is rabbits outpacing the effects of the latest virus, so a new strain has to be released every eight to 10 years if we are to stay ahead in the arms race.”

Andreas says the virus also has to be released at the right time so the young rabbits don’t develop immunity. Typically, this is late autumn.

ACT rangers took five years to eradicate foxes and rabbits from a new enclosure at the Mulligans Flat nature reserve, so Andreas says eradication is nearly impossible and the future relies on population management. Invasive Species Solutions is currently looking into bio-genetic technology to control numbers.

“We can’t become complacent around the impact of rabbits on the environment. As soon as we do, they’ll breed themselves into plague proportions.”

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In December, Riotact was reporting pet rabbits were being killed by calicivirus and now our homes are going to be invaded and our gardens devastated by marauding mutant rabbits!

I’m sure the ACT Government is on top of this. There’s bound to be plans for a kangaroo-style sterilisation program, a rabbit containment program in suburbs that back onto nature reserves and the retention of the “Don’t mow the long grass” policy, so that the little bunnies will have plenty to eat, without needing to dig up our backyard carrots.

With 40 kph speed limits and people electing to move towards “Active Transport”, there will be more opportunity for folk to catch themselves some viddles. And from 2035, it’ll be even easier to catch some grub, because they won’t hear us coming, in our silent EVs.

https://the-riotact.com/pet-rabbit-deaths-spark-warning-of-calicivirus-spread-in-canberra/522185

Thanks RiotACT for the informative article and the opportunity for everyone to comment. Being able to just quickly throw up a comment, not having to ever actually control rabbit impacts, means anyone can comment. IMO, the practical value of many of the proposed ‘solutions’ is only to demonstrate how little their authors understand of ecological processes. Fortunately not every decision is made democratically, so we usually have experts in charge who can ignore the majority advice from on-line sources. Democracy is complicated, hard, expensive and slow! We need it only because the alternatives to democracy can be worse!

When the rabbit virus is released can we also release one for cats!!!

I find this article interesting as, just a few weeks ago, I was reading a scientific article about how Myxomatosis has been mutating into a more deadly strain that has been killing higher numbers of feral rabbits. Might be an idea to work on getting that strain into the local populations.

With large rabbits at $30 in the butcher’s, surely there’s an opportunity for someone to make some money!

James Philemon12:21 pm 18 Jul 22

The time and money spend on bio-genetic solutions would be better spent paying for a group of trappers to come in and start capturing/killing them without having to wait for the right time to release a virus.

Or, if you really wanted to make a dent in the rabbit population, you’d sell hunting licenses and have at least two culls a year. Shooters would be happy, wild rabbit populations would decline (you could clean up foxes as well), and owners of pet rabbits wouldn’t have to worry about their rabbits dying from RHDV1 K5.

Call out Bob Katter, grab some wayward youth and give them all air rifles… should be all sorted within a week.

Maybe increasing the rates will scare the rabbits off.
The rabbits natural predators are the cities developers that take the rabbits natural land and turn it into concrete.

Stephen Saunders10:48 am 18 Jul 22

The newest rabbit control “plan” on the Environment website is 2016. In other words – tell somebody who cares.

The environment would be a lot better off, if we spent half as much on rabbit control, as we do on so-called carbon “offsets”.

Capital Retro10:12 am 18 Jul 22

ACT Park Rangers have small calibre high velocity .177 rifles which they use to kill injured wildlife. They are sometimes not adequate to kill a wallaby or kangaroo with the first shot but they would be ideal to humanely kill rabbits. I used to kill rabbits with my catapult when I was I was a lad.

Perhaps they could coordinate a shoot with the Department of Trams as the roads around city hill will be closed to traffic on and off for the next 5 years.

Even better, the meat could then be given to the inner-north hipster restaurants who could offer “pulled wild rabbit” at ridiculous prices.

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