From Our Co-Founder: A story about two islands

Feral Herald |

Author and biologist Tim Low was one of the Invasive Species Council’s co-founders 20 years ago. He wrote and published some of the earliest issues of Feral Heralds, and brings us another story in this edition.

This is a story about two islands, both in Western Australia.

One of them, Bernier, on the edge of Shark Bay, stands out as the Australian island that has saved more mammals from extinction than any other, five species all up. The djoongari or Shark Bay mouse (also known as the Gould’s mouse) survived on this 42 square kilometre landmass and nowhere else. The mala, burrowing bettong, banded hare-wallaby and Shark Bay bandicoot each survived on one or two other islands as well. All disappeared from the mainland long ago.

The other island is a case study in degradation. Goats were taken there in 1899 and not removed until 1984. Biologists who visited in 1959 found networks of goat trails in the better parts and the worst parts reduced to mobile dunes, running from one side of the island to the other, blamed on goats removing the plant cover. Goats were climbing into the crowns of shrubs and low trees to browse the tops of branches, many of which were broken off. Culls of 500 goats in the 1970s did little to improve the habitat.

I said two islands, but both descriptions actually apply to Bernier.

This island provides the kind of evidence that implicates cats and foxes rather than habitat degradation for Australia’s appalling tally of extinct and endangered mammals. There are many places on the mainland that kept better habitat than Bernier, but what mattered was its lack of cats and foxes. The island’s mammals survived savage droughts among those destructive goats, and at one stage they had a flock of sheep to contend with as well.

Bernier Island is close to Dorre, an island that saved the same species as Bernier apart from the mouse. No fire has ever been recorded on Bernier, but Dorre had serious fires in 1860, 1909 and 1973. Proactive fire management is vital for many species on the mainland but obviously not on these islands. One reason for the difference is foxes and cats on the mainland hunting with ease after fires. The last fire on Dorre was so destructive that rangers feared for the hare-wallabies and moved some to nearby Dirk Hartog Island. It had cats and they did not survive. The hare-wallabies did survive on scorched Dorre Island.

The five rare species have been helped with extra habitat by moving some individuals to fenced reserves on the mainland. One site chosen was Heirisson Prong, a peninsula of land in Shark Bay, close to Bernier Island. A predator-proof fence was installed across the neck of the peninsula, and bettongs and bandicoots added after cats and foxes were removed. The bandicoots thrived, multiplying to about 470, until cats breached the fence and killed them all. Foxes also breached the fence and killed bettongs. The project failed because the fence proved too difficult to maintain, corroding quickly in the salt air.

But Dirk Hartog Island has become very important for mammals today. The cats were removed and in 2018 it was stocked with hare-wallabies and mala, then with bandicoots and djoongari. They all seem to be doing well.

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Help protect NSW!

Our expert team has written a list of policy asks detailing exactly what the next NSW government needs to do to stamp out some of the worst invasive species impacts across the state. But they will only become a reality if every key political candidate at the 2023 NSW state election hears about it from you!

Dear National Deer Management Coordinator,

Please accept this as a submission to the National Feral Deer Action Plan.

[Your personalised message will appear here] 

I am very concerned about the spread of deer and am pleased that a national plan has finally been developed. Without urgent action, funding and commitment from all levels of government it is clear that feral deer will continue to spread and damage our environment.

The feral deer population in Australia is growing rapidly and spreading across the country, damaging our natural environment, causing havoc for farmers and foresters and threatening public safety. Unlike much of the world where deer are native, our plants and wildlife haven’t evolved to deal with these heavy hard hooved animals with a voracious appetite.
With no natural predators and an ability to adapt to almost all environments, they could occupy almost all of Australia unless stopped. Despite this, state and territory governments have been slow to respond and in Victoria and Tasmania they are still protected by law for the enjoyment of hunters.

This plan should be adopted by all governments but must also be underpinned by dedicated funding and clear responsibilities. A plan without funding or accountability is a plan that will fail and Australia cannot afford for this to fail.

In order to prevent the spread of feral deer and reduce their impact on our native wildlife, ecosystems and agriculture, I ask that the following recommendations be adopted for the final National Feral Deer Action Plan:

1. All federal, state and territory governments should adopt the National Feral Deer Action Plan and declare feral deer to be a priority pest animal species.

2. All federal, state and territory governments should commit to:

  • Contain deer to the existing large population areas.
  • Reduce and eradicate smaller and isolated populations.
  • Protect important environmental assets such as world and national heritage areas.
  • Develop and fund regional plans and strategies to manage deer populations which involve land managers across all tenures.

3. In order to drive action and the success of this plan, there should be dedicated Commonwealth funding and support for:

  • A permanent national feral deer coordinator position.
  • A permanent federal feral deer action committee with representatives from the commonwealth and state and territory governments and the environmental and agricultural sectors.
  • An ongoing public education campaign on feral deer.
  • A network of regional feral deer coordinators to drive local action across tenures.

4. The expected outcomes for the plan need to be more ambitious, with clear interim targets including:

  • Within one year, all States and Territories should have in place arrangements to implement the National Feral Deer Action Plan, including allocating dedicated funding for implementation.
  • Within one year, feral deer management plans should be developed for key environmental assets of national significance, including the Tasmanian Wilderness World Heritage Area, the Greater Blue Mountains, the Australian Alps, the Gondwana Rainforests and the Wet Tropics of Queensland.
  • Within five years coordinated landscape scale management should be in place where land owners, land managers, government and community are demonstrably working together.

5. A national feral deer containment map with three zones should be adopted. It should be more ambitious than the zone map in the current draft plan and there should be greater clarity in the naming of the zones. Improvements that should be adopted include:

  • Renaming the zones to better reflect the management intention to ‘Containment Zone 1’ (the current large population zone), ‘Containment Buffer Zone 2’ (the current buffer zone) and ‘Eradication and prevention Zone 3’ (the current small isolated population zone).
  • The NSW northern rivers area should be in the eradication and prevention zone as there are few feral deer currently in this region and eradicating isolated populations and preventing spread into this area is still possible.
  • The whole of South Australia should be in the eradication and prevention zone as eradication is the goal of the SA Government.
  • The Tasmanian region in the containment zone should be smaller to reflect greater ambition and potential for eradication of deer populations.
  • In eastern Victoria areas such as Wilson’s Promontory, Westernport islands and the Mornington Peninsula should be in the eradication and prevention zone.

6. There should be consistent laws and regulations across all states and territories that:

  • Recognise feral deer as a pest animal and treat them as such.
  • Establish a clear responsibility for all landholders and managers to be involved in feral deer control programs.
  • Set clear penalties to stop the wilful or negligent release of feral deer.
  • Prevent new deer farms in areas where no feral deer are present and phase out all deer farms in the eradication and prevention zone.
  • Enable enforcement of compliance, including on government land.

I support the follow principles being adopted in the final National Feral Deer Action Plan:

  • Feral deer are a pest and should be treated as such on all tenures, except on approved deer farms.
  • Federal, state and territory governments have a responsibility to fund the outcomes under this plan.
  • All land managers in areas where feral deer are present have a responsibility to be involved in feral deer control programs.
  • The focus of management efforts should be on eradication of isolated, satellite populations, protection of key environmental assets currently impacted and stopping the spread to new regions.
  • Feral deer control should be undertaken humanely, safely and professionally according to agreed protocols and all tools which meet this criteria should be adopted, including aerial control.
  • Funding for coordination, regional planning and community engagement is necessary for effective feral deer management.
  • Ongoing management and follow up control efforts are required to achieve long lasting results.
  • Rules and regulations should be consistent across jurisdictions and land tenures.
  • Recreational hunting is not an effective strategy for feral deer control and should not be relied upon.
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