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The natural world in Florida, as in much of the rest of the
world, is changing so rapidly that it is virtually beyond

comprehension. From a biological perspective, we often do not
know how to respond. Should we be alarmed and take imme-
diate action? I think we should definitely be alarmed; and, in
some instances, appropriate action can mitigate much of the
damage resulting from the changes. However, in other instances,
we have little choice but to remain passive observers of the most
intensive period of change in the Earth’s biological history.

I choose not to dwell on the obvious changes like habitat
loss due to development, changes in the environment due to
pollution, global warming, and simply because humans have
long since crossed the dangerous threshold of exceeding the
world’s carrying capacity for their own species. However, I will
comment on other circumstances in the role of an “old dinosaur
naturalist” (a title applied by younger colleagues to non-special-
ist biologists who began watching nature, catching critters, and
learning about natural processes as children). First, I am shocked
at the large number of herpetologists who seek to curtail the
rights of “new herpers” to keep and enjoy reptiles and amphib-
ians in their homes. Combine this with the loss of habitat and
changes that are causing substantive declines in the numbers of
our native reptiles and amphibians, and we will soon have a soci-
ety that is completely indifferent to these animals. The Discovery
Channel and all of the “TV cowboy herpers” who are providing
less-than-factual information to our kids will do little to encour-
age current youngsters to become passionate or even vaguely
concerned about conservation. We have already lost the politi-
cal momentum for wildlife conservation throughout the world.
What will the situation be like in 20 years without the stimula-
tion of having a live herp from which to learn?

The new generation of herpers is estimated to number in
the millions. When I was a kid, probably no more than 50 kids
and young adults in the whole of the state of Ohio were inter-
ested in herps. We formed a society so that we could talk and
learn from each other. Few books and no Conant Field Guides
were available in those days. In stark contrast, millions of peo-
ple care about herps today, but their interest seems very differ-

ent than ours. We wanted to learn about the animals in the wild
— but we also were excited about keeping them in captivity.
This desire led to efforts to breed them and develop good hus-
bandry, something the current generation takes for granted.

Advances in the captive breeding of some reptilian species
have resulted in easy access to a wide variety of herps. The cur-
rent popularity of herpetoculture is very similar to the tropical
fish craze some thirty years ago. One unfortunate result of this
is that people with pet herps (just like people with dogs and cats)
get tired of them or cannot keep them and find out they cannot
sell them or even give them away. This situation has contributed
dramatically to one of the big changes in our environment today
— the presence of invasive exotics.

The list of exotic animals and plants that can be found in this
country is quite extensive. Incidentally, many of the exotics that
have wrought havoc with the natural environment (and continue
to do so) were brought into the United States by various federal
and state agencies. Non-native plants and insects are causing seri-
ous damage to native wildlife and habitats. Southerners will read-
ily tell you about the devastation caused by Fire Ants (Solenopsis
spp.) and Kudzu (Pueraria montana var. lobata).

Now that we have millions of people with pet herps, the
release of herps has become an issue, especially in Florida. We
now have what I call “shake and bake ecology.” One can find
more than 40 exotic herps in Florida (see Mashaka et al. 2004.
The Exotic Amphibians and Reptiles of Florida, Krieger Publishing
Company, Malabar, FL). Without a doubt, some of these ani-
mals are exerting a profound impact on native herps. A single
adult Cuban Tree Frog (Osteopilus septentrionalis) can eliminate
all the native frogs around a house in one summer. Other species
may fit niches that are not filled and will have no immediate
impact on the environment, yet we cannot predict the full con-
sequences of such introductions.

One interesting twist to exotic releases is that no one has
complained about the Whooping Crane (Grus americana), an
exotic recently released in Florida by federal and state game
agencies. No evidence exists that this species has been a resident
of this state in either recent or prehistoric times. Apparently
these now resident birds (worth hundreds of thousands of dol-
lars in tourist revenues) prefer to eat many more snakes and frogs
than they do in their native habitat. One crane can find and eat
an amazing number of snakes. What impact will this have on
Indigo Snake (Drymarchon corais) populations? I suggest that
some of our agencies need to practice what they preach.

48 IGUANA  •  VOLUME 12, NUMBER 1  •  MARCH 2005 ASHTON

C O M M E N T A R Y

Comments from an Old Naturalist 
About Exotic Species and 

a New Herpetocultural Ethic
Ray Ashton

The Gopher Tortoise Conservation Initiative
Newberry, Florida

Opinions expressed are those of the author and may or
may not reflect those of the IRCF.



IGUANA  •  VOLUME 12, NUMBER 1  •  MARCH 2005 49COMMENTARY

Recently, two lizard controversies have reared their heads in
Florida: the Nile Monitor (Varanus niloticus, see Iguana
10(4):119–120) population in and around Cape Coral and the
Spiny-tailed Iguanas (Ctenosaura similis, see Iguana
10(4):111–118) on Gasparilla Island (see “Newsbriefs” in this,
p. 58, and recent issues). In the former instance, local citizens
have lodged complaints (probably initiated by one or two folks
and then snowballing). Many are deeply concerned that these
predators will impact listed species like the Florida Burrowing
Owl (Athene cunicularia floridana) and nesting sea turtles. Dog
and cat lovers, who illegally let their wildlife-devastating animals
run loose, are worried that their predatory pets will, in turn,
become prey for introduced exotics. This may be the case, and
we should be alarmed — and we should study the situation to
determine what really is happening. Of course, what stimulated
this article is that residents of Gasparilla Island have fussed about
ctenosaurs coming into their yards and destroying their (mostly
exotic) vegetation. Naturally, when a biologist suggested that we
shoot them, the resultant outcry of disgust obscured the reality
that few alternatives exist to this direct method of “getting rid of
the problem.” Trapping lizards, darting lizards, or any other
method of taking the lizards is less efficient and certainly more
stressful for the animals. The fact is that a lot of ctenosaurs live
there — and a considerable effort and a great deal of money will
need to be expended to get rid of them. The same is true for the
monitors on Cape Coral. These are species that have established
a strong foothold in their new environment. Unlike many of the
geckos that were largely restricted to specific buildings near the
Miami airport, the monitors and Spiny-tailed Iguanas, along
with Green Iguanas, will likely be part of the Florida landscape
as long as one remains.

When exotic plants like Brazilian Coffee (Coffea arabica) or
animals such as the iguanas achieve huge population sizes, the
cost in money and time essentially makes them impossible to
eradicate. Some control may be possible, but eradication is
unlikely. In my opinion, I think we have little choice but to live
with the situation.

However, the introduction of exotic amphibians and rep-
tiles is not a good idea and the new generations of herpetologists
and herpetoculturists should develop a new conservation ethic
if they wish to retain their right to keep animals in captivity. We
used to tell the herpers of my day that they should take only the
specimens that served a specific purpose. Today, we need to
establish some new rules, which should include:
1. Before buying any pet, learn about it! Do not count on the

pet store staff to know more than you do. BUY AND READ
A BOOK about the animal. Learn about the species’ natu-
ral history, not just how to keep it in captivity. For example,
do you know that some tortoises eat more than 400 species
of plants? Much of this type of natural history information
is not listed in care manuals, but it may well be the key to
successfully keeping and breeding some reptiles.

2. Acquire your pet from a reputable source. Do not become
part of the problem by encouraging the collection of rare
species from ever-declining habitats. In almost every
instance, no justification exists for buying anything but cap-
tive-bred animals (one exception might be to catch your
own exotic species — folks on Gasparilla, for example,
would appreciate your efforts).

3. Make sure that your caging is appropriate for the type of
animal you plan to keep — and that it is escape proof! If real
(or artificial sunlight) is required, don’t settle for less, or
you’ve likely doomed your pet to a nasty death.

4. Ascertain your pet’s nutritional requirements and make sure
you can devote the time and money necessary for purchas-
ing and preparing the right food on an appropriate schedule.

5. Many keepers are avid about breeding their pets. Social
needs are enormously variable from species to species, but
most amphibians and reptiles are not social and do not need
companions. In many instances, adding an additional ani-
mal to a confined space may create stress that can lead to
immunocompromise and disease. An iguana has a home
range in the wild that can cover several acres of land. How
big is the cage you can provide?

6. Have an escape strategy for when you want to get rid of
your pet (or its offspring). Perhaps the pet store or animal
dealer from which you obtained it will permit you to return
it, or you might be able to take it to an animal rehabber who
may have better contacts. If all else fails, take it to a veteri-
narian or animal shelter to be euthanatized. Sound awful?
Well, think about what may happen to the animal before
you hand over the money for it. DO NOT LET THE
ANIMAL GO, even if it is a species that is found locally. If
you have exotic and native herps, be sure to keep them in
separate cages (or, better yet, separate rooms). The release of
pets may result in the transfer of deadly pathogens to pop-
ulations of native species. Such a situation can be far more
dangerous to wildlife than the animals competing with or
preying on each other.

7. Avoid confrontations with neighbors. Be respectful of their
concerns and fears. Educate them, but don’t try to force
them to accept your exotic pet. If you want to take your pet
outside, do it in a private place. One incident is all that’s
needed to set non-herpers on the warpath. That, in turn,
will inevitably lead to knee-jerk responses from local politi-
cians. Ultimately, it all boils down to common sense.

Spiny-tailed Iguanas (Ctenosaura similis) are firmly entrenched on
Gasparilla Island, where residents might be well advised to learn to live
with them. Photograph by John Binns.




