pig | ConservationBytes.com

World’s largest successful island-wide eradication of invasive pigs

11 06 2026

Just over two years ago I reported the ‘likely’ eradication of feral pigs from Australia’s third-largest (4,405 km²) island — Kangaroo Island. I indicated ‘likely’ because the program still required the proof-of-eradication phase to be completed before an official declaration could be made.

Yesterday I had the immense honour to take part in the official declaration ceremony held on Kangaroo Island near Karatta in the island’s southwest.

Executive Director (Biosecurity) of the Department of Primary Industries and Regions South Australia (PIRSA), Georgie Cornish, presenting the official declaration plaque to the Chair of the Kangaroo Island Landcape Board, Andrew Heinrich. Some of the main people responsible for the successful program’s implementation are also in the photo, including Senior Biosecurity Officer, Dr Myall Tarran (centre).

I can’t begin to emphasise enough how monumental this outcome is for biodiversity conservation, not just for South Australia, or even Australia, but globally.

This is without a doubt the largest island eradication of pigs anywhere in the world. Considering that most eradication (or even density-reduction) programs fail, the success is even more outstanding.

Feral pigs are identified as a ‘Key Threatening Process‘ under the Australian Environment Protection and Biodiversity Conservation Act 1999. They are also the fifth-costliest single species in the country, with only cats, rabbits, fire ants, and ragweed engendering higher costs.

I am also taking some personal pride in the outcome because I had a small part to play. One dreary Sunday morning back in 2022, the head of PIRSA’s Invasive Species Unit Dr Brad Page rang me with an urgent request. “Corey”, he said without much preamble, “I need a model to tell me how much it would cost to get rid of pigs on Kangaroo Island, and I need it by this afternoon”.

Read the rest of this entry »

Comments : Leave a Comment »
Tags: biological invasion, biosecurity, eradication, invasion biology, invasion science, social licence, surveillance
Categories : agriculture, alien species, Australia, biodiversity, conservation, demography, ecology, environmental economics, environmental policy, governance, harvest, invasive species, investment, mammal, management, modelling, pig, planning, population dynamics, recovery, research, rural, science

5000 piggies, 500 piggies, 100 piggies, … and there there was none

4 12 2024

The Black Summer bushfires of 2019–2020 that razed more than half of the landscape on Kangaroo Island in South Australia left an indelible mark on the island’s unique native biodiversity, which is still struggling to recover.

*Flinders Chase National Park on Kangaroo Island after the 2019-2020 Black Summer fires (credit: CJA Bradshaw)*

However, one big bonus for the environment’s recovery is the likely eradication of feral pigs (Sus scrofa). Invasive feral pigs cause a wide range of environmental, economic and social damages. In Australia, feral pigs occupy about 40% of the mainland and offshore islands, with a total, yet highly uncertain, population size estimated in the millions.

Feral pigs are recognised as a key threatening process under the Environment Protection and Biodiversity Conservation Act 1999, with impacts on at least 148 nationally threatened species and eight threatened ecological communities. They are a declared invasive species and the subject to control programs in all Australian jurisdictions.

Motion sensing cameras deployed during the eradication program capture feral pigs using their snouts to search for soil-borne food. This behaviour, called rooting, creates large areas of disturbed soil, killing native vegetation and spreading invasive weeds and pathogens (credit: PIRSA).

In a new article published in Ecosphere, a collaboration between PIRSA Biosecurity and the Global Ecology Laboratory at Flinders University analysed optimal strategies for culling feral pigs.

Read the rest of this entry »

Comments : 1 Comment »
Tags: cost of invasive species, detection, eradication, invasive species, invasive species control, Kangaroo Island
Categories : agriculture, alien species, Australia, demography, ecology, economics, environmental economics, environmental policy, invasive species, mammal, management, modelling, monitoring, pig, population dynamics, research, South Australia, southern Australia, stochasticity

And this little piggy went extinct

24 11 2021

Back in June of this year I wrote (whinged) about the disappointment of writing a lot of ecological models that were rarely used to assist real-world wildlife management. However, I did hint that another model I wrote had assistance one government agency with pig management on Kangaroo Island.

Well, now that report has been published online and I’m permitted to talk about it. I’m also very happy to report that, in the words of the Government of South Australia’s Department of Primary Industries and Regions (PIRSA),

Modelling by the Flinders University Global Ecology Laboratory shows the likelihood and feasibility of feral pig eradication under different funding and eradication scenarios. With enough funding, feral pigs could be eradicated from Kangaroo Island in 2 years.

This basically means that because of the model, PIRSA was successful in obtaining enough funding to pretty much ensure that the eradication of feral pigs from Kangaroo Island will be feasible!

Why is this important to get rid of feral pigs? They are a major pest on the Island, causing severe economic and environmental impacts both to farms and native ecosystems. On the agricultural side of things, they prey on newborn lambs, eat crops, and compete with livestock for pasture. Feral pigs damage natural habitats by up-rooting vegetation and fouling waterholes. They can also spread weeds and damage infrastructure, as well as act as hosts of parasites and diseases (e.g., leptospirosis, tuberculosis, foot-and-mouth disease) that pose serious threats to industry, wildlife, and even humans.

Read the rest of this entry »

Comments : 4 Comments »
Tags: Australia, environment, eradication, feral pig, Kangaroo Island, modelling, PIRSA, Population, population model, South Australia, Sus scrofa, wildlife management
Categories : agriculture, alien species, Australia, conservation, demography, disease, ecology, environmental policy, harvest, invasive species, investment, management, mathematics, modelling, pig, predator, research, restoration

Eat a feral a week

22 03 2012

Just a quick post this week about something I’ve been contemplating for a while.

What if every Australian pledged to eat a feral animal a week?

Yes, I know that it’s a bit out of the pitch, and I’m sure not everyone would do it. Nor would it be physically possible for one person to eat an entire camel, buffalo or deer in a week – but hopefully you get the picture.

Why propose this? Australia is quite over-run with feral animals. Some quick stats:

We have well over 1,000,000 camels (Camelus dromedarius), possibly closer to 1.5 to 2.0 million
There are in excess of 150,000 swamp buffalo (Bubalus bubalis), most of which are found in the Top End
Although estimates are rather imprecise, there are possibly up to 23 million feral pigs (Sus scrofa) across the country
As equally variable, there are an estimated 2.6 million feral goats (Capra hircus) in Australia
There are around 5000 to 7000 banteng restricted to the Cobourg Peninsula
I’m not aware of any population size estimates, but Australia hosts six species of feral deer: fallow (Dama dama), red (Cervus elaphus), chital (Axis axis), hog (Hyelaphus porcinus), rusa (Cervus timorensis) and sambar (Rusa unicolor) in 1000s of subpopulations spread around the continent’s fringe

Now we have, of course, many other ferals (cats, rats, foxes, mice), but I don’t think too many people would want to eat them. I have personally eaten feral pigs, camels, buffalo, goats, and red, fallow and sambar deer, mostly from my own research trips or from friends who hunt. Read the rest of this entry »

Comments : 11 Comments »
Tags: Australia, banteng, buffalo, camel, Feral, goat, introduced animals, pig
Categories : buffalo, bushmeat, conservation, cuisine, food, harvest, invasive species, livestock, mammal, pig

Computer-assisted killing for conservation

12 01 2010

Many non-Australians might not know it, but Australia is overrun with feral vertebrates (not to mention weeds and invertebrates). We have millions of pigs, dogs, camels, goats, buffalo, deer, rabbits, cats, foxes and toads (to name a few). In a continent that separated from Gondwana about 80 million years ago, this allowed a fairly unique biota to evolve, such that when Aboriginals and later, Europeans, started introducing all these non-native species, it quickly became an ecological disaster. One of my first posts here on ConservationBytes.com was in fact about feral animals. Since then, I’ve written quite a bit on invasive species, especially with respect to mammal declines (see Few people, many threats – Australia’s biodiversity shame, Shocking continued loss of Australian mammals, Can we solve Australia’s mammal extinction crisis?).

So you can imagine that we do try to find the best ways to reduce the damage these species cause; unfortunately, we tend to waste a lot of money because density reduction culling programmes aren’t usually done with much forethought, organisation or associated research. A case in point – swamp buffalo were killed in vast numbers in northern Australia in the 1980s and 1990s, but now they’re back with a vengeance.

Enter S.T.A.R. – the clumsily named ‘Spatio-Temporal Animal Reduction’ [model] that we’ve just published in Methods in Ecology and Evolution (title: Spatially explicit spreadsheet modelling for optimising the efficiency of reducing invasive animal density by CR McMahon and colleagues).

This little Excel-based spreadsheet model is designed specifically to optimise the culling strategies for feral pigs, buffalo and horses in Kakadu National Park (northern Australia), but our aim was to make it easy enough to use and modify so that it could be applied to any invasive species anywhere (ok, admittedly it would work best for macro-vertebrates).

The application works on a grid of habitat types, each with their own carrying capacities for each species. We then assume some fairly basic density-feedback population models and allow animals to move among cells. We then hit them virtually with a proportional culling rate (which includes a hunting-efficiency feedback), and estimate the costs associated with each level of kill. The final outputs give density maps and graphs of the population trajectory.

We’ve added a lot of little features to maximise flexibility, including adjusting carrying capacities, movement rates, operating costs and overheads, and proportional harvest rates. The user can also get some basic sensitivity analyses done, or do district-specific culls. Finally, we’ve included three optimisation routines that estimate the best allocation of killing effort, for both maximising density reduction or working to a specific budget, and within a spatial or non-spatial context.

Our hope is that wildlife managers responsible for safeguarding the biodiversity of places like Kakadu National Park actually use this tool to maximise their efficiency. Kakadu has a particularly nasty set of invasive species, so it’s important those in charge get it right. So far, they haven’t been doing too well.

You can download the Excel program itself here (click here for the raw VBA code), and the User Manual is available here. Happy virtual killing!

CJA Bradshaw

P.S. If you’re concerned about animal welfare issues associated with all this, I invite you to read one of our recent papers on the subject: Convergence of culture, ecology and ethics: management of feral swamp buffalo in northern Australia.

C.R. McMahon, B.W. Brook,, N. Collier, & C.J.A. Bradshaw (2010). Spatially explicit spreadsheet modelling for optimising the efficiency of reducing invasive animal density Methods in Ecology and Evolution : 10.1111/j.2041-210X.2009.00002.x

Albrecht, G., McMahon, C., Bowman, D., & Bradshaw, C. (2009). Convergence of Culture, Ecology, and Ethics: Management of Feral Swamp Buffalo in Northern Australia Journal of Agricultural and Environmental Ethics, 22 (4), 361-378 DOI: 10.1007/s10806-009-9158-5

Bradshaw, C., Field, I., Bowman, D., Haynes, C., & Brook, B. (2007). Current and future threats from non-indigenous animal species in northern Australia: a spotlight on World Heritage Area Kakadu National Park Wildlife Research, 34 (6) DOI: 10.1071/WR06056