Saving NZ’s threatened species: 3 possible paths

Posted by Big Rat on Campus on May 3, 2015 in Rat News | Subscribe

Helicopters arrive to be loaded with 1080 cereal bait to be spread in the Arawhata Valley, South Westland. Photos by Stephen Jaquiery.
How adaptable? A New Zealand robin.

Conservation will need to evolve beyond the constant sense of
crisis, to achieve an inclusive long term vision. Steve
Urlich calls for a new approach to saving species outside
protected areas.

Conservation in New Zealand is at a crossroads. Threatened
species continue to face extinction outside of protected
areas. There are also serious social issues around poison
drops in forests.

A new approach is needed to resolve these conundrums. I
discuss three possible paths we could take to preserve our
biological treasures.

Recently, I suggested in the New Zealand Journal of Ecology
that only one of these paths could lead to a future where
some native birds were able to survive, with little or no
further help from us (

More on that later. So what are the paths that we could
tread?Path 1 – continue the current situation. Ongoing
predator control occurs by trapping or bait stations, or at a
landscape scale by aerial drops of 1080.

There is no end point with this ”endless highway”. Rather,
it is ongoing for the next 10 10,000 years if our descendants
can be convinced.

Advocates argue that predator control is akin to maintaining
a road. Ongoing operations are needed to protect the gains
made for native species’ survival.

This path is as an endless arms race to develop new tools to
stay ahead of wily, elusive predators as they evolve
behavioural and genetic resistance.

However, there is little awareness that some native birds can
also evolve, reflecting a widely held but mistaken view that
all native species are incapable of coping with predators.

Path 2 – complete predator eradication. The Predator Free NZ
movement argues that travelling the endless highway is
necessary until species destroying pathogens and poisons are
ultimately developed.

Advocates point to significant advances in control methods
over the past 40 years, and the promise of genetic
engineering to defeat natural selection.

However, the predator free lobby lacks rigorous scientific
analysis and pragmatic thinking to clear the massive social,
ecological and economic obstacles from this path.

Pathogen releases, and laying of poisons and traps, will
occur around each home, school, office, mall, park and public
space. Repeated eradication attempts may occur to kill all
individuals at the same time. This could result in civil
disobedience of a scale not seen since the 1981 Springbok

People who hide their pet rats, possums, ferrets, mice or
cats may face arrest. Trade in these would become a lucrative
black market.

All container and cruise ships may have to be quarantined
offshore for weeks while they are ”cleansed” of rats and
mice to prevent reinvasion. International flights will be
delayed for hours as inbound flights are systematically

The economic costs will still pale in comparison to the cost
of killing predators from Stewart Island to Kaitaia. And, if
cats and stoats are eradicated but not mice or rats, then
expect rodent plagues.

Path 3 – assisted adaptation. As hard as it is, we may have
to accept predators are here to stay. That does not mean,
though, that all is lost in helping native species to adapt.

International research is revealing that evolution can occur
much more rapidly than expected. Some species can adapt
within several hundred generations, provided populations have
enough behavioural flexibility or genetic variability.

For our native birds, this flexibility can be understood as
the ability to change nesting behaviour to avoid attracting
the attention of predators, choosing inaccessible sites to
nest or being ”skittish”.

Conservation managers can actively assist adaptation by
reducing predation pressure enough so that natural selection
favours flexible individuals.

This means more predator fences with predator control
outside. As the safe areas fill up, young birds will look
outside for territories and food. Exposing these individuals
to reduced predation pressure should favour the selection of
”predator savvy” birds.

Why has this not occurred already? There are intriguing hints
that bellbird and tui are already adapting. So we may not
have been looking for it.

We have also mistakenly thought that all native species
cannot adapt. This is because many species face unrelenting
attacks from different predators that they have not co
evolved with.

These encounters come too often, and are too lethal, for many
species to resist, so natural selection has been overwhelmed.
For example, in one night, a saddleback may face lethal
threats from stoats, possums, rats or cats.

Clearly, too, some species are in evolutionary traps, such as
the kakapo, and require ongoing protection on offshore
islands and behind fences, as they are unlikely to ever be
able to cope with predators.

Science investment is needed to investigate how, and which,
native species can adapt. Meanwhile, we need to protect hard
won conservation gains.

Conservation will need to evolve beyond the constant sense of
crisis, to achieve an inclusive long term vision. Having a
clear 100 year goal may also help quell public unease about
predator control methods and the end outcome for

Dr Urlich is an ecologist who has worked in native
forest, high country and marine ecosystems.



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