In two separate social media posts this week, in two different states and both concerning wild fallow deer management, the shadowy Greens-aligned lobby group the Invasive Species Council (ISC) has once again demonstrated its preference for spin over substance and alarmism over sober management discussion.
The examples are instructive.
Not because they reveal anything new about deer management, but because they show how statistics can be selectively presented to create a narrative that simply doesn’t withstand even the most basic scrutiny.
South Australia: When 28,000 isn’t more than half of 40,000
The first post concerned the South Australian “Feral Deer Eradication Program” (their words, not ours – the deer aren’t “feral” and eradication is a pipe dream).
According to the ISC, the program has been a success because more than 28,000 deer have been culled from an estimated population of 40,000 since 2022.
At first glance that sounds impressive.
Until you apply the most elementary principle of wildlife population dynamics.
Deer reproduce.
Fallow deer populations typically grow rapidly under favourable conditions. Does commonly produce a fawn each year and juvenile survival rates can be high where habitat is suitable. In unmanaged populations this can result in annual growth rates commonly estimated between 20–30%.
Which means that if you begin with 40,000 deer and remove 28,000 over four years, you have not removed “more than half” the population at all.
You have simply removed 28,000 animals from a population that has been breeding the entire time.
Depending on recruitment and survival rates, the population may well have remained stable – or even increased slightly during that period.
This isn’t controversial. It is Wildlife Management 101.
The ISC’s framing therefore ignores the central biological fact (besides reducing impacts) that determines whether a control program succeeds or fails: net population change, not raw kill numbers.
On the figures they themselves have circulated, the program cannot reasonably be described as a success. At best it may have slowed population growth. At worst it has achieved little more than a temporary suppression effect.
Yet this didn’t stop the ISC from declaring the program successful and demanding another $1.5 million per year in funding.
Taxpayers should reasonably expect a higher evidentiary bar before millions more dollars are committed.
Tasmania: When 42 is a “Crisis”
The ISC’s second post this week concerned deer-vehicle collisions in Tasmania.
Here the organisation claimed that deer are “crashing into Tasmanian cars at record rates”, citing increases of 160% in crashes and 330% in insurance costs.
Again, the percentages sound alarming.
But percentages without context are one of the oldest tricks in the advocacy playbook.
The raw numbers tell a very different story.
According to the figures cited:
- 2021: 16 insurance claims
- 2022: 12 claims
- 2023: 26 claims
- 2024: 26 claims
- 2025: 42 claims
In other words, the dramatic “160% increase” represents a change from 16 claims per year to 42 claims per year.
That is less than one claim per week across the entire state of Tasmania.
The increase is also not even consistent. One of those years saw a decline of 25%, followed by two identical years before the jump to 42.
From a statistical perspective, that is not yet a trend. It is a short dataset that could easily represent normal fluctuation.
More importantly, the ISC provides no comparison with the total number of wildlife vehicle strikes in Tasmania.
Wallabies, wombats and kangaroos are involved in vastly larger numbers of collisions every year. Without that context, the deer figures are meaningless.
But context rarely helps alarmist narratives.
The pattern
What both examples demonstrate is a pattern.
Large percentages.
Selective framing.
Missing biological context.
And an immediate call for more taxpayer funding.
None of this reflects the careful, evidence-based wildlife management discussion that any Australian state actually needs.
A warning for Victoria
Victorians should be particularly alert to this pattern.
The Victorian Deer Control Strategy, strongly supported and championed by the Invasive Species Council, ran its course after tens of millions of dollars in public expenditure.
Despite the scale of that investment, it delivered little in the way of measurable long-term outcomes.
With a state election due in November, it is almost certain that we will see a redoubling of the ISC’s familiar strategy – dramatic claims, selective statistics, and urgent calls for larger government spending programs.
Wildlife management is complex and often controversial.
But one thing is clear.
Policy should be driven by evidence and outcomes, not by misleading percentages and social media alarmism.
Our advice to all political parties ahead of the election is simple:
Treat the Invasive Species Council’s claims with the scrutiny they deserve and avoid being drawn into divisive, expensive and counter-productive policy driven by advocacy rather than evidence.
