Biology Reference
In-Depth Information
but Congress has responded only by proposing (and occasionally passing) legisla-
tion addressing one small facet of the alien invasion crisis at a time. One result of
this dystopian approach has been at least 110 naturalizations of reptiles and
amphibians in the United States since the 1960s.
This contrast in approaches taken by New Zealand and the United States may be
further clarified by considering each country's most successful operations against
alien herpetofaunal incursions. As discussed earlier, New Zealand quickly and suc-
cessfully eradicated an incipient invasion of
Limnodynastes
frogs in 1999, surveying
and treating a large area of the Waitakere Ranges within a few weeks (Whitaker and
Bejakovich, 2000). The United States has no such success (or even attempt) at rapid
eradication of a new herpetofaunal incursion. The United States does, however,
have a successful program for containing the highly invasive brown treesnake to
Guam (see Chapter 4), thereby protecting other Pacific islands from further inva-
sions by this pest. One measure of this program's success is that brown treesnake
sightings in Hawaii declined from eight in the period 1981-1994 (0.57 snakes/
year), to one dead animal since the program has been fully functional (0.077
snakes/year). Despite this demonstrable success, the program has existed for its
entire 14-year tenure without base funding, that is, it has continued solely on year-
to-year funding liable to termination at any time by Congress. But base funding is
generally required for the hiring of government employees (as opposed to tempo-
rary contractors). Further, no single agency is accountable for the program. As a
result, funding flows have been intermittent, especially from the Department of
Defense, which is responsible for the majority of departing vehicular traffic on
Guam and, correspondingly, poses the largest threat of snake dispersal to other
Pacific islands. Hence, even though the brown treesnake prevention program on
Guam has been a clear operational success -the only herpetological example that
the United States can point to - inadequate administrative design has subjected it
to repeated funding crises throughout its history, making it perennially liable to
unintended failure.
The administrative contrast between New Zealand and the United States with
respect to taking the risk of alien invasions seriously and assigning clear responsi-
bility for responding to them couldn't be more stark. And this is reflected in their
recent invasion histories. Some of the difference in naturalization success between
the two countries could, of course, be due to the presence in the United States of
warmer regions more equable to invasion by alien herpetofauna. But New Zealand
does not lack for hospitable habitat, and this certainly does not provide a complete
explanation. Instead, the fact that New Zealand has responded to the threat of alien
invasions in a coordinated manner largely free of political interference for the past
15 years while the United States has limped along with piecemeal, uncoordinated
actions is certainly key to explaining the different on-the-ground results. Particularly
important is the fact that New Zealand has largely prohibited trade in pet reptiles
and amphibians whereas the United States has no meaningful import restrictions on
animals available for private ownership. The importance of this point is confirmed
by data from Australia, which has also prohibited private trade in alien herpeto-
fauna and which is unique among the regions surveyed in Chapter 2 in having most
