Pest-free Goal Won’t Be Achieved Without New And Better Tools
New Zealand’s goal to become predator free by 2050 will remain an unrealised dream unless new technologies and advances in social engagement continue to be developed, researchers who first promoted it say.
A team
from the University of Auckland has developed a statistical
tool more commonly employed in the medical field, known as a
time-to-event analysis, to calculate the chances of pest
eradication success over time. Normally the tool
investigates how different therapeutic treatments will
affect the lifespan of a patient suffering from a
life-threatening disease.
But in this case the
researchers used the model to investigate how different
factors are likely to impact the amount of time a New
Zealand island suffers rat invasion. They fed their model
with a wide range of island data including size, distance to
the mainland, public or private ownership, human habitation
and whether rats had already been eradicated.
Islands
were then ranked for the likelihood of rat eradication
success and how long it might take to get underway.
The
results were sobering. Just two out of 18 highest-ranked
islands in the model – the ones with the highest chance of
eradication success – would be rat-free by 2025 and
overall just 14 out of 74 islands were likely to be rat free
by 2050.
If New Zealand’s rate of eradication
implementation continues as-is, the country will not be
rat-free anytime in the foreseeable future, says doctoral
student Zachary Carter who led the study.
“Our results
should be viewed as an examination of PF2050’s potential
outcome if transformative eradication advances are not
made,” he says.
“Fortunately, universities,
government researchers and private enterprise are already
involved in exploring new and exciting transformative
technologies to overcome limitations in the existing
eradication toolbox and they will be essential to PF2050’s
success.”
Those new technologies include genetic tools
which could produce a “Trojan female” whereby all male
offspring are infertile, and species-specific toxins such as
norbormide which could be highly effective and target
only rats.
Social impact assessments and frameworks such
as those developed by Professor James Russell that help
achieve community support for conservation projects will
also be critical.
“Advances in both technology and in
attaining community buy-in that are more effective than what
we have had in the past will be vital and they will need to
be if we are to increase the rate at which projects
succeed,” he says.
The research team included Professor
Russell, jointly appointed to the University of Auckland’s
School of Biological Sciences and Department of Statistics,
and Professor Thomas Lumley from the University of
Auckland’s Department of Statistics. The research is
published in Global
Change
Biology.