New Zealand's response to pest invasions
New Zealand's unique situation
Geographically isolated, New Zealand has been severely affected by alien species such as stoats, possums, rats and feral cats, that began to arrive with human settlement 700-800 years ago.
Over half of our native vertebrate fauna has become extinct, countless invertebrate species have been lost, while over 100 native plant species are classified as critical or endangered.
Addressing the threats
In the last 50 years New Zealand practitioners have earned an international reputation for effectively addressing the threats posed by invasive species.
Eradication of invasive predators on off-shore islands has led to the recovery of threatened endemic species such as the flightless nocturnal parrot kakapo, the wattlebird tieke (or saddleback) and the ancient reptile tuatara.
The successful eradication of a growing suite of invasive plants and animals from islands – and the recording of significant ecological responses has opened the door to a new era in conservation in New Zealand. Many species recovery programmes and island restoration plans now include provisions to eradicate invasive species from islands as an important step towards achieving broader conservation goals.
These successes have led not only to a new impetus amongst conservation practitioners, but also to a mounting groundswell of public interest in, and support for, conservation.
‘Mainland islands’
Important advances have also been made on the main islands of New Zealand where sustained control objectives – rather than eradication – are more appropriate. In some cases, techniques applied as part of island eradication operations have now been adapted and applied to sustained control programmes back on the mainland.
New Zealand’s national icon, the kiwi, is declining rapidly due to predation by invasive mammals such as dogs and stoats. Dramatic increases in kiwi numbers have been recorded following intensive pest control at a number of mainland sites. ‘Mainland Island’ projects aimed at recovering an array of threatened species have resulted in significant pest control targets being achieved and sustained, and also led to reductions in the significant costs and risks associated with maintaining on-going pest control regimes.
Conservation outcomes from control programmes are now being recorded that could not have been imagined just a few years ago. The refinement of ‘best practice’ procedures, community support and ‘ownership’ of pest control operations, and ecological restoration at mainland sites are now features of the New Zealand conservation scene.
Biosecurity initiatives
New Zealand’s biosecurity programmes aimed at limiting the number of new invasions are also hailed as ‘setting the gold standard’ and are emulated internationally.
Widespread recognition of the value of effective biosecurity programmes in managing the risks that new invaders pose to our economy, public health and way of life, as well as to our biosecurity, underpins high levels of public support for biosecurity in New Zealand.
As international travel and trade continues to escalate the risks of new and potentially invasive species establishing in New Zealand can also be expected to climb. Coordinated by BiosecurityNZ, a number of government agencies are focused on effectively and consistently applying pre-border and at-border biosecurity measures, and undertaking rapid response actions when incursions are detected.
Refinement and collaboration
‘Adaptive management’ approaches are increasingly being used in New Zealand to better understand the relationships between invasive species and the communities in which they exist, and to improve management as it proceeds. A feature of adaptive management is that it requires scientists, pest managers and decision-makers to work cooperatively.
There are many examples in New Zealand of such cooperation focused on managing invasive species. Landcare Research scientists have been – and continue to be closely involved in many of these programmes, providing research and technical advice underpinning these successes.
Our scientists have worked alongside staff from the Department of Conservation, regional government, territorial authorities, landowners, Māori and others to address key management issues. We continue to support New Zealand agencies, providing advice on improving invasive species management approaches and techniques and undertaking research to underpin policies, strategies and new approaches.
This history of involvement and close collaboration with New Zealand management agencies has led to us building significant expertise in a range of related disciplines and a detailed understanding of the ecology and impacts of many invasive plants and animals, as well as of the interactions between them. We will continue to value and nurture these links with New Zealand management agencies and invasive species management practitioners.
While there are important differences between New Zealand and other countries, and between individual sites within countries, the principles underpinning successful invasive species management developed in New Zealand are widely applicable.
