Biology Reference
In-Depth Information
A final difference in approach between New Zealand and the United States is
that the former explicitly adopts the precautionary principle in devising policies
pertaining to alien species. This allows policymakers to opt for excluding a species
or eradicating an alien in the absence of scientific certainty of its invasiveness. In
contrast, the United States excludes only species known to be pests elsewhere. The
precautionary approach assigns burden of proof for safety to the importer, whether
the introduction is intentional or a statistically predictable accidental component of
legal cargo transport. Under this paradigm, instances of scientific uncertainty are
decided in favor of avoiding invasion costs. In contrast, under a reactionary para-
digm, burden of proof to demonstrate species risk falls on those social institutions,
organizations, or individuals challenging a proposed introduction, and instances of
scientific uncertainty are decided in favor of allowing the importation to proceed.
Because invasiveness is so difficult to conclusively demonstrate a priori for most
species, and impossible for species not previously imported, the reactionary
approach defaults to unfettered importation of virtually all biota. With respect to
reptiles and amphibians, this problem is particularly acute for the pet-trade path-
way. The relentless search for novelty in the exotic pet trade intersects with the
reactionary regulatory paradigm to ensure that regulations only prevent the impor-
tation of species that were formerly popular as pets and have already become natu-
ralized. This results in a predictably high rate of invasions in countries adopting
such a regulatory paradigm. Regulated industries understandably prefer a reactionary
approach, as it allows them to externalize the costs of invasive species management.
Part of the reason New Zealand and Australia have more successfully responded to
the threat of alien invasions is because their governments have recognized these
previously externalized costs, attempted to measure them, and responded so as to
minimize them.
An additional reason for governmental inaction has been inadequate informa-
tion. There is often bewilderment among even concerned officials about how to
respond to herpetological invasions because control techniques have not previously
been reported in the literature or encountered by politicians or agency personnel.
And there are few experts that may be consulted for advice on how to respond to
such invasions. (As one example, the response to the invasion of South Florida by
Burmese pythons relies heavily on expertise from the brown-treesnake program,
potentially limiting staff availability for both programs.) In the absence of clearly
prescribed solutions, few officials have the clout to devote scarce institutional
resources to programs with an uncertain outcome. This leaves inaction as the
default (non-) response position. This unhelpful circumstance is potentially ame-
nable to research directed to developing standard control/eradication procedures
for reptiles and amphibians, much as has been achieved for rodents in the past
three decades.
The point of dwelling at some length on these contrasts in bureaucratic struc-
tures and response approaches is that one can identify minimal organizational
standards and requirements for effective governmental response to invasive aliens,
including invasive herpetofauna. These include combining responsibility for alien
prevention and eradication in a single agency with clear accountability and professional
