Biology Reference
In-Depth Information
of the major pathways relevant for any particular jurisdiction, and assessment of
individual species (or genera) proposed for deliberate introduction. The former
would ideally be done at the scale of particular jurisdictions - typically countries,
but sometimes island groups or other areas showing regional biotic differentiation
- because the geographical analyses used here are too coarse-grained to accurately
assess pathway variation within most regions. The United States will be an excep-
tion to that rule, however, because the large majority of my data for North America
comes from that country. In some cases - such as small countries - there may be
insufficient data to generate country-specific risk assessments. In those cases, the
regional analyses provided here may be of surrogate use in determining cargo-
inspection priorities. That may be appropriate in much of the Caribbean, for example,
because the greatest recent risk for many countries in the region has proven to
be infested nursery shipments from southern Florida. More usually, though, one
would desire country-specific statistics indicating volume of relevant trade
items likely to harbor hitch-hiking herpetofauna. Ideally, if one could identify
economic statistics that correlate well with transport likelihood for alien herpetofauna,
one could use those statistics to set inspection priorities. This is especially likely
to hold true for nursery shipments because climatic discrepancy between origin
and destination is not likely to be a confounding factor. For other cargo types,
information on cargo origin would also factor into risk determinations inasmuch
as climatic disparity between origin and destination might obviate successful
transport of many species.
Risk assessment for particular species proposed for deliberate introduction
(typically as pet animals) may prove difficult to achieve because of the vast diver-
sity of biological idiosyncracies among the total pool of imported/importable
herpetofauna. However, as discussed earlier, progress has been made in assessing
establishment risk and invasion risk for a diversity of vertebrates, including
herpetofauna (Bomford et al., in press), so broad-scale rules are likely to provide
some discriminatory assistance. Those findings suggest that great scope remains
for developing a usefully predictive screening algorithm, but insufficient attention
has been devoted to that effort, so effective screening tools are currently lacking
for most jurisdictions.
Preventing introduction cannot, however, be the sole strategy for minimizing
future herpetological invasions for the simple reason that no single prevention
method is perfect. Although current control technologies for alien herpetofauna
are frequently inefficient or poorly developed, in the longer term technological
improvements should be achievable, making eradication and control increasingly
viable and sensible options for managing some invasive herpetofauna. However,
there will remain relevant biological constraints (crypsis, high demographic rates
of increase) likely to bar application of these methods to many species. And fiscal
constraints on control programs will remain common. Eradication and control
operations can logically be done by any form of institution, but government
action will often be key because governments are frequently the only entities that
can bring a sufficiency of resources to bear on such problems. As well, govern-
ments readily provide a logical nexus around which actions of a variety of
