Predator-free New Zealand? Conservation ethics

Sunset over the Southern Alps, with the silhouette of a Kea (Nestor notabilis), an alpine parrot species native to New Zealand

Biodiversity hotspots

Without a doubt, New Zealand is a biodiversity hotspot. It consistsof two islands that have evolved independently for 80 million years, accompanied by environmental gradients. With such strong heterogeneity in the landscape, New Zealand is home to a plethora of different habitats. From wind swept tussocks, to lush beech forests, to alpine, to sub-tropical scrub. Not to mention you can drive from the Tasman Sea across to the South Pacific Ocean in less than a day across either island. 80% of the plants, 90% of the insects, and all of the reptiles in New Zealand are endemic (known only to the continent). One of the most unique aspects of New Zealand’secology is the fact that birds have long-ruled this island. l Until humans reached the island there are thought to have been no top predatory mammals, other than marine mammals. In fact, the only native terrestrial mammals known to the island are bats. While island-occurring species, coupled with time, and environmental variability evolutionarily pairs quite well with rarity, and extinction, it also couples well with invasion biology.

The war on invasive species in New Zealand

Invasive mammals were first brought to New Zealand in the early 1900’s. The introduction of “The Big Three” the ship rat (Rattus rattus), the Australian brushtail possum (Trichosurus vulpecula) and the stoat (Mustela erminea) has had immense repercussions on the native flora and fauna of the small island nation, as the native inhabitants have long evolved without any means by which to defend against these predators. The control of these invasive mammals, and the few other species that have subsequently been introduced over time, have existed since the early 1950’s. In 2014 however, efforts to eradicate these predators significantly increased with the formation of “Predator-free New Zealand”, an ambitious government campaign sought to eradicate all non-native mammals from the island nation by 2050.

Photo of an Australian possum caught in a trap (Nelson Lakes, NP)

Traditionally, much of this work has been done “the dirty way” using baited traps, with people set out on foot to check, clean, and reset them. However, since the late 1950’s increased usage of the poison sodium fluoroacetate (aka 1080) has progressively been used as a more effective tool for covering large remote areas. This poison has caused a great deal of controversy among conservationists and locals alike, for the poison has been found to not just kill the non-native predatory mammals, but all living beings (plants and animals alike). This poison has been found to cause birth defects, and damage to the reproductive system, brain, heart, and other organs. While many New Zealanders care very much about their native flora and fauna, and families and livestock, what many are unaware of is the downstream effects of consistent pesticide application on not just “the big three” but all biodiversity on the small island continent, even the threatened bird species it is sought after to protect.

Sign warning people entering Nelson Lakes, NP of recent 1080 poison baits dropped

This article addresses the ethical constraints surrounding the war on invasive species, and proposes an alternative paradigm of ‘compassionate conservation’ towards addressing the issue of invasive species in New Zealand. To address the ethics associated with the current invasive species management regime, the author begins by a discussion of war theory, and Jus ad bellum considerations within the context of the Predator Free New Zealand framework, which states:

Ethics associated with proper warfare conduct

• War must be waged by a legitimate or competent authority

• There must be a just cause

• There must be right intentions

• There must be an announcement of intention

• War must be a last resort

• There must be reasonable hope of success

• Proportionality (i.e. a reasonable balance between probable good and harm).

Non-lethal methods of biodiversity conservation

In this review, the author suggests that the current Predator Free New Zealand initiative has an unrealistic and expensive objective, and the expenses associated with this project will detract from environmental initiatives that may be more environmentally efficient such conservation or habitat restoration. The author also suggests that the war on the big three appears to be more concerned with protecting primary industries and the economy (particularly tourism), not conservation. Finally, the author claims 1080 poisoning not to be a “last resort” and suggests further research be put towards non-lethal methods of pest control that do not cause unnecessary suffering to not only the “enemy” but to all living creatures. The author also suggests a more realistic shift should be taken towards a holistic conservation strategy that includes lower levels of pest control with land conservation and habitat regeneration. The war on invasive species does not have to be an unjust mass-eradication that kills everything in its path, by incorporating appropriate moral guidelines associated with proper war conduct, the author suggests a possible future for New Zealand invasive species management.

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Samantha Andres

I am a plant and community ecologist interested in the dynamics and drivers of vegetation dynamics across different ecological communities. I have had experience working in coastal, desert, forest, riparian and alpine ecosystems. Much of the work I have recently been doing has involved research related to understanding the life histories and environmental requirements of threatened and endangered species, in order to create more effective conservation and management strategies. I have a deep passion and respect for the world we live in, and have made it my goal to support that through the work that I do.

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