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Forty-one exotic species of amphibians
and reptiles are known to occur in
Florida, and more are being discovered on
a regular basis. A hospitable climate, dis-
rupted natural ecosystems, a mobile and
growing human population, and service
as the major transportation center for the
U.S. pet trade all contribute to the
increasing numbers of invasive species.

ENGE AND KRYSKO (2004. Florida
Scientist 67:226–230) documented an
established population of the Asian
agamid lizard commonly called the
Bloodsucker (Calotes versicolor) in St.
Lucie County, Florida. This population
was apparently introduced in 1978, and
approximately 100 specimens have been
captured by two commercial collectors in
the past 10 years. All specimens were cap-
tured from nocturnal roosts 1–9 m high
in weeds, vines, bushes, and trees. The
known population boundaries extend
approximately 10 km east-west and north-
south, and they encompass citrus groves,
Brazilian pepper (Schinus terebinthifolius)
thickets, mesic flatwoods, and canals. The
authors did not attempt to assess the pos-
sible ecological impact of this species on
native wildlife, but it has been known to
feed on small vertebrates in Asia.

KRYSKO ET AL. (2004. Florida Scientist
67:249–253) documented an established
population of the Veiled or Yemen
Chameleon (Chamaeleo calyptratus) in
Fort Myers, Lee County, Florida. The
authors recorded at least 70 individuals,
including both genders and all size classes
in consecutive years, indicating a repro-
ducing population. Chamaeleo calyptratus
also has been reported from areas near
Lehigh Acres and Alva, Lee County, and
Naples, Collier County, suggesting inde-
pendent introductions of this popular
exotic lizard. Monitoring of this popula-
tion should continue, and eradication
should be attempted if adverse ecological
impact on native species is observed.

ENGE ET AL. (2004. Florida Scientist
67:303–310) documented populations
of the introduced African Rainbow
Lizard (Agama agama africana) in
Homestead, Miami-Dade County;
Hollywood, Broward County; Palm City,
Martin County; Punta Gorda, Charlotte
County; and Sanford, Seminole County.
The Homestead and Punta Gorda popu-

lations have been established for over 10
years and have expanded at least 0.5 km
from the point of introduction. The
Palm City population has been estab-
lished since 1999 and the Sanford popu-
lation since 2000. All lizards were in
urban or suburban situations. Maximum
clutch size and maximum snout-vent
length (SVL) of male and female A. a.
africana in Florida exceeded those in
native Nigerian populations. All adult
females (> 94 mm SVL) collected
May–August contained 5–18 vitellogenic
follicles or oviductal eggs, but a female
collected on 19 September was not
gravid. Monitoring should be conducted
to determine whether the species could
invade natural habitats and exert a nega-
tive impact on native wildlife.

The Nile Monitor (Varanus niloticus), the
longest lizard in Africa, was first observed
in southwestern peninsular Florida in the
Cape Coral area of Lee County in about
1990. From April 2001 through July
2003, ENGE ET AL. (2004. Southeastern
Naturalist 3:571–582) compiled data
from 146 sightings or captures of this
species. Numerous individuals of all size
classes were observed or collected, sug-
gesting the occurrence of a reproducing
population. Although records are mostly
confined to Cape Coral, the data indicate
that V. niloticus has recently expanded its
range northwards and to nearby islands.
Because this large lizard has the potential
to disperse into nearby ecologically sensi-

Gravid female and neonate Bloodsuckers
(Calotes versicolor) from St. Lucie Co.,
Florida.

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Adult and juvenile (Chamaeleo calyptratus)
from Lee Co, Florida.

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African Rainbow Lizard (Agama agama
africana) from Miami-Dade Co., Florida
(UF 134222).

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This 5-foot, 15-pound Nile Monitor
(Varanus niloticus) was captured at a residence
in Cape Coral.

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Non-native Reptiles in Florida

IGUANA  •  VOLUME 13, NUMBER 1  •  MARCH 2006 71CONSERVATION RESEARCH REPORTS

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tive areas and preserves where it could
pose a serious threat to waterbirds,
Burrowing Owls (Athene cunicularia), sea
turtles, and other native wildlife, popula-
tion monitoring and eradication are war-
ranted.

KRYSKO AND ENGE (2005. Florida
Scientist 68:247–249) confirmed the
existence of the Butterfly Lizard (Leiolepis
belliana) in Miami, Miami-Dade
County, Florida. The authors found L.
belliana active during the daytime in an
area encompassing six square city blocks,
where it was observed basking and forag-
ing on open grassy lawns and inhabiting
burrows. The population of L. belliana
originated from a tropical fish dealer and
has been established since at least 1992.
If eradication of the Miami population is
desired, it should be attempted while the
population remains localized.

Green Iguanas (Iguana iguana) are firmly
established in southern Florida, includ-
ing a large population on Key Biscayne.
In its native range, I. iguana is known to
be almost strictly herbivorous. Juveniles
are often reported to be somewhat
omnivorous, but prey items are rarely
identified. The tree snail Drymaeus mul-
tilineatus is common in southern Florida,
where it is found on stems and leaves and
in edificarian habitats. TOWNSEND ET AL.
(2005. Southeastern Naturalist 4:361–
364) examined I. iguana stomachs from
Bill Baggs Cape Florida State Park, Key
Biscayne, and discovered D. multilineatus
in two lizards, including 12 snails in one
juvenile I. iguana. The large and rapidly
growing I. iguana populations in south-
ern Florida may have the potential to
devastate some highly localized native
species of tree snails.

MESHAKA ET AL. (2005. Southeastern
Naturalist 4:521–526) searched for intro-
duced Northern Curlytails (Leiocephalus
carinatus armouri) along Florida’s south-
eastern coast from Port Salerno, Martin
County, north to the Indian River/Brevard
County line to determine the extent to
which this species has expanded its range
since its introduction to Palm Beach
County almost 50 years ago. They found
the distribution of these lizards to be
almost uninterrupted in heavily modified
coastal habitats from northern Broward
County through Palm Beach County.
Despite urban heat islands, the authors
suggested that frost isotherms would pre-
vent stable populations from becoming
established north of Fort Pierce on the
eastern coast and just below Sarasota along
the state’s western coast.

Recent studies of geographic patterns of
nonindigenous species richness suggest
that a few key biogeographic and anthro-
pogenic factors explain much of the vari-
ation in the richness of established
species. However, the factors identified in
these studies may be taxon- and scale-
specific or general rules might apply
broadly across taxa and spatial scales. To
address this issue, SMITH (2006.
Biological Conservation 127:327–335)
identified factors that contributed signif-
icantly to variation in nonindigenous
herpetofaunal richness at a relatively
small spatial scale, the county level, in
Florida. The author also used the Jaccard
similarity index to determine if non-

indigenous species affect the biotic simi-
larity of the herpetofaunas of Floridian
counties. County latitude strongly and
negatively affected nonindigenous her-
petofaunal richness, explaining approxi-
mately two-thirds of the variation in this
variable. To a smaller degree, human
population and university presence both
related positively with nonindigenous
herpetofaunal richness. Several other
variables, including county land area,
were not significantly related to non-
indigenous herpetofaunal richness. The
consistent importance of human popula-
tion to nonindigenous species richness in
this and past studies suggests that the
influence of anthropogenic factors may
be universal and are as or more impor-
tant than the natural biogeographic fac-
tors that generally relate with native
species richness. The author found no
evidence of overall homogenization, but
a significant relationship between
homogenization scores and distance
between counties suggested that the
effect of nonindigenous herpetofaunal
richness on the similarity of county bio-
tas is scale-dependent, such that adjacent
counties tend to experience homogeniza-
tion. The results of this and similar stud-
ies may be useful in predicting the intro-
duction and spread of nonindigenous
species and in evaluating the effects of
such introductions on native biodiversity.

72 IGUANA  •  VOLUME 13, NUMBER 1  •  MARCH 2006 CONSERVATION RESEARCH REPORTS

Butterfly Lizard (Leiolepis belliana) from
Miami-Dade Co., Florida.

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The tree snail Drymaeus multilineatus is com-
mon in southern Florida, where it is known
to be eaten by introduced Green Iguanas
(Iguana iguana). Such observations suggest
that the large and rapidly growing I. iguana
populations in southern Florida may have
the potential to devastate some highly local-
ized native species of tree snails.

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Northern Curlytail (Leiocephalus carinatus)
from Palm Beach Co., Florida.

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