There is no doubt Norfolk Island is a special place. Its hardy inhabitants are friendly and resourceful, its wildlife is spectacular, and many of its native species are found nowhere else on Earth.
But tragically much of Norfolk Island’s incredible wildlife is also in trouble. Forty-six plants, five birds, two reptiles and five land snails are listed as threatened under Australia’s national environmental law.
Invasive species such as rat, cats, Argentine ants and others are a key threat to many of the islands’ native species. Predation by the black rat, for example, is a specific threat to the golden whistler, scarlet robin, green parrot, most nesting seabirds, endemic reptiles,
land snails and other invertebrate species. It is also a threat to the plant species Achyranthes arborescens, Melicope littoralis, Meryta latifolia and Ungeria floribunda via consumption of seeds and fruits, which has had the result of restricting regeneration.
Protecting the biodiversity of Norfolk Island requires ongoing vigilance to prevent new pest incursions and the effective control, and potentially complete eradication, of existing invasive species. The Invasive Species Council, together with TierraMar and our partners on the island have been engaged in these efforts for more than five years.
We published Norfolk Island: Protecting an Ocean Jewel in 2017 to highlight the importance of strong biosecurity to protect the island’s exceptional conservation values while the its administration was in a state of flux. Self-governance for Norfolk Island was revoked the year before and new administrative systems under direct federal government control and funding were being set up.
The new Norfolk Island Regional Council is now well established, but there is still much work needed to build up the island’s conservation infrastructure and systems to protect it from harmful plants and animals from the outside.
The environment-centric biosecurity system we had hoped for – one that uses controls similar to state-based biosecurity laws to protect the unique aspects of the island – are still to be fully established.
The great advantage of islands is that we can more easily wind back the clock and eradicate invasive species that have gained a foothold through mistakes, hitchhiker arrivals or deliberate introductions.
Norfolk Island’s most damaging invaders are rodents and feral cats. As our report shows there are many others too, including Argentine ants and the Asian gecko. Some 430 exotic plant species have established, more than double the number of the known indigenous plants, so weed invasion remains an important threat.
While the 35km2 island may appear small, addressing these threats will be a major undertaking. It will also require the backing of the local community.
In 2017 we started a project to provide rodenticide and materials to help the Anson Bay community create a network of rodent bait stations around properties adjacent to Norfolk Island National Park.
We then identified ways to further harness philanthropic support to remove impediments to world-class conservation management the whole island deserves.
A fundamental stumbling block was the lack of a contemporary, island-wide vegetation map. By preparing a detailed vegetation map and scientifically determined vegetation types, planning for the areas worth protecting or restoring can be better justified.
The Invasive Species Council secured funding to compile two maps. The first was the current native vegetation remnants, grouped into 14 distinct plant communities. The second was the vegetation communities predicted to occur prior to 1750, long before the start of European settlement.
The 1750 vegetation map would guide landholders with rehabilitation efforts and give them confidence of the best native plants to plant in any location. It would also help attract funding for more sophisticated and ambitious conservation projects.
Plant experts Naomi Christian and Kevin Mills, with project support from Ray Nias at TierraMar, completed this ground-breaking work earlier in the year.
The results will be published in late 2021 as the two vegetation maps and an easy-to-understand explanation of the vegetation communities.
Parks Australia had secured $150 million of federal government funding to conduct rodent baiting and accelerate cat baiting efforts. However, missing from the cat work was a program to ensure pet cats were not adding to the problem.
Again, the Invasive Species Council secured complementary funding for a free cat desexing and microchipping program with the aim of covering the island’s population of domestic cats. Our project partner, Parks Australia, is supporting the local vet in offering this service to all island residents that own a domestic cat.
Additional support is provided by the Invasive Species Council to purchase feral cat cage traps and a contractor to put them in the field.
Norfolk Island’s tourism dependent economy has been ravaged by COVID-19 travel restrictions. Almost every business has been severely affected, council has shed staff and locals have been grounded. It is hard to be optimistic in these times.
Islanders have learned the hard way how to be tough, independent and resourceful, so their commitment to protecting its unique wildlife and the needed conservation work will continue.
The Argentine ant eradication program is into the second year of a three-year, $1.3 million eradication program. Progress is being made in winding back infestations in about a dozen sites. CSIRO has been trialling a heavy payload drone to more efficiently deliver ant baits. A major challenge will be delivering ant bait to the sheer seaside cliffs. The ants have shown a remarkable capacity to quickly recolonise areas from small areas left untreated.
The 2018 Norfolk Island environmental strategy and the recently drafted pest and noxious weed management plan are a good framework to protect and restore the island’s natural assets.
With an accurate vegetation map and greater efforts to reduce the damage from the worst pests – rodents and cats – the island is well on track to restoring its ocean jewels.
Our work on Norfolk Island would not have been possible without the support from many project partners. Funding for most of the work was sourced from multiple grants from the Eldon and Anne Foote Trust of the Lord Mayors Charitable Foundation, who have become an important player in Norfolk Island’s conservation work, while the preparation of the vegetation maps for publication was funded by the Norfolk Island Regional Council. We have appreciated the generous support from islanders, Norfolk Island National Park, Norfolk Island Regional Council and the federal Department of Infrastructure and Regional Development.