Biology Reference
In-Depth Information
positive support for the introduction, opposition to the killing of vertebrates, and
lack of appropriate control methodologies. As we saw above, disbelief among
biologists that a population was established hindered recognition of the python
invasion in the Everglades, and disbelief among government officials that frogs
posed a problem was a major factor in the failure to respond in a timely fashion to
the coqui invasion in Hawaii (Kraus and Campbell, 2002). Disbelief in the desirability
or feasibility of eradication currently appears to be preventing French governmental
response to the relatively recent invasion of
Xenopus laevis
(Fouquet and Measey,
2006). Even in the case of brown treesnakes on Guam - among the best docu-
mented and studied herpetological invasions - there was widespread dismissal of
snakes as the cause of avian disappearance in the early 1980s (J.T. Marshall, 1985;
Jaffe, 1994). By the time the snake-predation hypothesis became widely accepted,
the birds were gone. To this day it remains easy to hear Guam residents express
disbelief that brown treesnakes are a problem, simply because they happen never to
encounter the (nocturnal) snakes. My experience is that this type of disbelief
remains common among scientists as well, including many specializing in invasive-
species research. Disbelief that alien reptiles and amphibians constitute problems
or that they merit response is likely to remain widely rooted among the general
public, but it is to be hoped that education will increase sensitivity among managers
and biologists to the potential severity of herpetological invasions. We are not yet
to that goal.
Positive support for herpetological invasions will typically involve only a very
small slice of the public, but it has the potential to undermine even determined
control efforts widely supported by the general public. Spread of coqui by water-
garden clubs and private individuals who liked the sound of the frogs' calls abetted
widespread and rapid invasion by that species across Hawaii Island, as did the
erroneous belief that the frogs control mosquito and nut-borer populations (Kraus
and Campbell, 2002). Many herpetological invasions are initiated as deliberate
releases motivated by the desire to have a favorite species living nearby. This is
clearly true for
Phelsuma
spp.,
Gekko gecko
, and
Chamaeleo jacksonii
releases in
Hawaii, and it apparently applies to a number of releases in Florida as well (Wilson
and Porras, 1983; Meshaka et al., 2004a). This situation can be made worse if mon-
etary opportunities are provided by the release. The rapid spread of
C. jacksonii
in
Hawaii, for example, resulted in large part because numerous individuals wanted to
ranch them, establishing populations near their homes from which they could col-
lect animals for sale in the pet trade. Similar pecuniary advantage has been taken
of some populations of alien lizards in Florida (Krysko et al., 2003b; Enge and
Krysko, 2004; Enge et al., 2004c; T. Campbell, 2005), and it would be unsurprising
if this too has led to founding of additional populations there.
Opposition to killing invasive herpetofauna may arise because certain segments
of the population oppose the killing of any vertebrate. This was an argument used
by a few people opposed to coqui control in Hawaii. Opposition by public “animal-
rights” groups had little effect in this instance because exasperation with the frogs'
noise was widespread among the public. However, opposition by a government
official for the same reason served to hinder response operations for a year or so
