




































Iguana 10.3 color covers (Page C1)


“I’m optimistic that the St. Lucian Iguana will be
saved, and that we will be able to protect them
in such a way that they will be able to expand
into new areas. My dream is to see the iguana
repopulate a much wider area of the island…”

— Donald Anthony, 
Wildlife Officer, St. Lucia

S
t. Lucia is one of the Windward Isles in the
Lesser Antillean chain, which extends from
just southeast of the Puerto Rico Bank
almost to South America. With an area of

610 km2, the island is topographically and biotically

diverse. Montane uplands are covered by rainforest,
whereas coastal areas are characterized by dry wood-
lands. Human influence is evident in the abundant
agricultural areas and numerous communities.

Green Iguanas (Iguana iguana) are widely
distributed through Central and much of South
America, and have been introduced and become
established in many tropical and subtropical areas
throughout the world. St. Lucia is the northern-
most of the Antilles on which these animals occur
naturally.

Introduced Green Iguanas are all too common
and indeed, have become pests in parts of Florida
(see Newsbriefs, p. 94). On some of the more

The St. Lucian Green Iguana — 
A Special Case?

John S. Bendon
Bath, England

71IGUANASeptember 2003

Large adult male St. Lucian Green Iguana. Note the pale ground color and the length of the dorsal crest scales.



northerly isles of the Lesser Antilles, they pose a
threat to populations of their endangered relative,
Iguana delicatissima, through competition for
food and habitat and by reproducing at a higher
rate. In some areas, they also have threatened the
integrity of the unique I. delicatissima gene pool
by hybridizing with the native animals.

Unlike the introduced populations, which
have become established only in recent years, St.
Lucian Iguanas may have been isolated from other
Green Iguana populations for as long as hundreds
of thousands of years — and consequently appear

to be a bit different. Most obviously, St. Lucian
Iguanas have “horns,” dramatically enlarged scales
that project conspicuously from their snouts.
These vary considerably in size and seem to be
more prominent in older animals. Although rela-
tively rigid and firm (much more so than the mid-
dorsal crest spines, for example), they do “bend”
from side to side. They also are thicker in diame-
ter than dorsal crest scales, although, in cross-sec-
tion, they are somewhat flattened laterally. The
coloration and shape of some large scales on the
lower jaw also differ from those of other Green

72 IGUANA Volume 10, Number 3

An adult male St. Lucian Green Iguana (a) and a young adult female St. Lucian Green Iguana (b) compared to male (c) and
female (d) Green Iguanas from elsewhere in the species’ range. Note the horns and differing shapes of scales on the jaws.
Drawings by the author.

A

B

C

D



Iguanas. Catherine Malone, Purdue University,
has examined the DNA of many iguanids, and
recently has been concentrating on St. Lucian
Iguanas. Her work is yet to be published, but pre-
liminary results show distinct genetic differences
between St. Lucian and other Green Iguana pop-
ulations.

Although based on a relatively small sample of
a few dozen adults and recognizing considerable
variation among individuals, St. Lucian Iguanas
appear to undergo ontogenetic changes in color
and pattern. Hatchlings are bright or yellowish
green with cloudy gray or black bands. These
bands seem to fade in the first year or two of life,
when the iguanas are a very intense green. As the
animals continue to age, the green (usually) loses
its intensity and the bands appear to darken. In the
oldest (or, at least, the largest) individuals, the
green fades to a pale gray and the black bands are
quite prominent.

Until recently, no research has been conducted
on these iguanas. Now, with support from the
Durrell Wildlife Conservation Trust, Matthew
Morton of Bristol, England and local assistants are
implementing a project in cooperation with the

Forestry Department (part of the Ministry of
Agriculture) of the St. Lucian government. The
Forestry Department has provided field assistance
and technical expertise, as well as vehicles and
office facilities. Head of Department Brian James
and Deputy Michael Andrews have taken a keen
interest, and Donald Anthony and Alwin Dornelly
from the Department’s Wildlife section are work-
ing closely with Morton. Karen Graham of the
Sedgwick County Zoo (Kansas), Bill Toone of the
San Diego Zoo, and Catherine Malone also have
contributed greatly by assisting with the Union
Zoo’s (St. Lucia) exhibit, education and commu-
nity outreach planning, and blood sampling from
wild and captive iguanas for DNA analysis. Labor
and travel expenses for Graham and Toone were
covered by their respective institutions, and
Malone received funding through the
International Iguana Foundation and the Miami
Metro Zoo to cover material costs for improve-
ments to the zoo exhibit and educational posters.

The goals of the project are to: (1) determine
the population size and distribution of St. Lucian
Iguanas, (2) establish the population’s taxonomic
status, and (3) protect and conserve current pop-
ulations.

Blood is drawn for DNA analysis and PIT tags
(transponders) are inserted in each individual. The
latter can be read using a type of barcode reader,
and a unique number permanently identifies the
animal, even if the tag turns up in the belly of a
predator. Some iguanas have been equipped with
transmitters and radiotracked.

73IGUANASeptember 2003

A female iguana in the Limiere area.

Over 1000 hatchlings were observed on the main nesting
beach this year, but survival rate is very low due to predators.



The largest St. Lucian Iguana processed to
date weighed over 5 kg and had a snout-vent
length of 45 cm. Current estimates of adult popu-
lation size range in the hundreds, certainly less
than 1000. Over 1000 hatchlings have been

observed on the main nesting beach, but very few
of that number survive to maturity.

St. Lucian Iguanas are restricted to the north-
eastern part of the island, including the beaches.
Several unsubstantiated reports also place at least a
few animals in the southeast. Sightings or recent
reports of iguanas are absent for the entire interior
of the island (moist forest) and the entire western
coast.  The small number of older reports that are
available are difficult to interpret. At least some of
these areas should be suitable for iguanas, so why
aren’t they there? Any number of factors might be
responsible.

“Dogs kill adult iguanas, either in hunts with
people (a few people still eat them for food) or,
more commonly, it seems, because they are
allowed to run around unattended, killing
whatever they can. Hunting (by people) was
reportedly more common in the past, and many
local people attribute perceived declines in
iguana numbers at one site in particular to 

74 IGUANA Volume 10, Number 3

An adult male St. Lucian Green Iguana that was recaptured
on several occasions.

Illustration by John Binns.



over-hunting. The dreaded mongoose takes
eggs and hatchlings; this year (unlike last) a cat
was found, killing hatchlings, at the main nest
site. Natural predators of hatchlings seem to be
predominantly various species of herons and the
American Kestrel. Manicou (opossums) and rats
may theoretically take hatchlings, though there
is no direct evidence of this. There is a single
observation of a Boa constrictor in the act of
swallowing an adult, though generally boas are
small here and I think this is likely to be
uncommon.

“Traditionally there has been heavy sand mining
at both the beaches where iguanas nest. These
sites are also used by Leatherback Turtles and it is
known that their nests have been destroyed in
this way. So, it seems likely that iguana nests
would likewise be at risk, although sand mining
is now less intense than in the past at these sites.
At one of these beaches ‘semi-feral’ pigs are

reported to open turtle nests, though there is no
evidence of the opening of iguana nests as yet.

“Clearance of large areas of land for banana
growing in the last few decades may have had
an effect (during a habitat-use study using
radiotracking last year, all nine tracked iguanas
‘pointedly’ avoided banana plantations).”

— Matt Morton

“The main things that are killing iguanas are
dogs – especially dogs – cats and people.”

“When I see them, I’m feeling happy. They see
me, they give me a lot of signs – they’re shaking
their heads [head bobbing]. They’re fine with
people … Let it be, in the wild, like anyone else.”

— ‘Seko’, a St. Lucian 
field assistant on the project

75IGUANASeptember 2003

Sign funded by the International Iguana Foundation and the
Durrell Wildlife Conservation Trust; one of many posters made
by parents and teachers for pre-school age local children, and
an iguana lacing trainer, also made by an adult for children.



The International Iguana Foundation and the
Durrell Wildlife Conservation Trust have funded
signs asking people to keep dogs on leashes in the
main areas occupied by iguanas.

“Roots Farm is a cooperative farm, run by Rastas
in one of the areas on St. Lucia where iguanas
are still found. They practice organic farming and
grow a wide range of mixed crops, in contrast,
for example, to monocultures of bananas, which
are commonplace in many areas. What drew our
attention to this place is that, unlike most places
on the island, this was one where you had a
fairly good chance of seeing an iguana. And
that’s because of the Rastas’ gentle and
sympathetic attitude toward iguanas and all
wildlife. Hunting and unleashed dogs are not
tolerated on their land.”

— Matt Morton

“I think, in this culture people, not knowing 
too much about wildlife, do not have an
understanding of their importance and, as a
result, do not appreciate those animals as
people who are wildlife-sensitive do. We’ve had,
in the past, to do extensive work in terms of
education with the St. Lucia Parrot, and we can

see the successes of that. We know that even
schoolchildren know some of the basic facts
about the parrot and appreciate it. We would
like to create that sort of attitude in people
toward the iguana, but we know that, right
now, some people just look at the iguana as a
lizard, that it’s not good looking, and it might
not be friendly.”

— Alwin Dornelly, 
Wildlife Officer, St. Lucia

Clearly, this mirrors
an attitude that unfor-
tunately is common
throughout tropical
regions of the world.
People fail to appreciate
their wildlife resources
and are likely to dislike,
misunderstand, or
merely exploit them.
The only effective
means of changing atti-
tudes is education.
Posters designed as part
of a local school’s activ-
ity program and other
activities such as games,
coloring books, and
children’s lacing train-
ers made by parents
and teachers are meth-
ods that are being used

76 IGUANA Volume 10, Number 3

An iguana burrow on St. Lucia.

Young adult St Lucian Iguana.



77IGUANASeptember 2003

As part of the effort to protect and conserve the
current population of St. Lucian Green Iguanas,
Matthew Morton of the Durrell Wildlife Conservation
Trust has been regularly checking hatchlings on the
nesting beach at Louvet. Among this year’s hatch-
lings, Morton observed a number of anomalies.

Multiple “nest sites” are located at Louvet, at most
of which multiple females have nested. Four of the
main sites and five of the less heavily patronized ones
have been fenced. Thus, certain effects can be
described as “per nest-site” and others as “per
clutch,” and have a higher probability of being due
to nesting conditions or to circumstances originating
with the parents, respectively. However, causative
agents remain in all cases speculative.

Some individuals appeared grubby and
unhealthy with patches of gray scales in various loca-
tions on their bodies. Some clutches seem to have
many individuals with this condition, whereas most
have no affected animals. This condition also was
observed in a few of last year’s hatchlings. This does
not appear to be normal shedding and preliminary
observations suggest that the affected hatchlings also

tend to have hatching weights toward the low end
of the scale.

One suggested cause for the grey patches was a
bacterial infection acquired in the nest. This would
account for some clutches being affected more than
others. The mother could pass a bacterial infection to
the developing embryos. Bacteria will incubate in the
developing eggs and can produce systemic infections
in the hatchlings. Secondary opportunistic organisms
can localize topically and result in the skin discol-
oration. Fungal infections also may be responsible,
particularly given the damp nesting environment.

A different potential cause is poor nutritional sta-
tus of the mother. The absence of necessary trace
minerals such as selenium or vitamins such as B1 may
singly or in combination result in problems such as
malabsorbed yolk sacks or too little yolk to support a
hatchling in the last hours before hatching and the
first days thereafter.

Morton also observed some overt birth defects,
mainly tails that were kinked very slightly in the ter-
minal few millimeters and occasionally a more pro-
nounced kink higher up. Again this seemed to affect
several individuals in some clutches and none in oth-
ers. This is most likely attributable to extreme incuba-
tion temperatures, although the possibility of
inbreeding within a small population exists as well. A
single individual displayed what appeared to be
hydrocephaly, a condition that, in humans at least,

Anomalous Hatchlings
All photographs by Matthew Morton.

These hatchling St. Lucian Iguanas emerged from a
single nest; the missing portions of their tails probably
fell victim to a rat or land crab invading their nest.

Hatchling St. Lucian Iguanas: the individual on the left
suffers from patches of gray scales that most likely were
caused or exacerbated by bacterial or fungal agents, the
hatchling on the upper right suffers from possible
hydrocephaly or an abscess, whereas the youngster on
the bottom right is quite healthy.



to get the message to adults and children at the
same time.

On some islands people are brought up eating
iguana as a delicacy. This is not sustainable.

“Actually, we’ve always recognized that the St.
Lucian Iguana was in dire straits in terms of its
numbers and its chance of survival because
we’ve had a history of hunting iguanas in St.
Lucia. Even [though] we had the wildlife laws
passed in 1980 with a fine of 5,000 [Eastern
Caribbean] dollars for anyone convicted of
catching or killing an iguana [St. Lucian law also
allows for fines and imprisonment for possession
of an iguana], it is very difficult to catch
somebody ‘in the act,’ because the areas are
very remote and [representatives of the Forestry
Department] are stretched in terms of numbers:
we don’t have the Forestry Officers to police
everywhere. When you go to investigate an
area, people are tight-lipped — they won’t
speak out. It’s hard to get any firm evidence. We
have been trying to source funding for a long
time to get extra help. In the Wildlife Section, I
am the only person working there until recently.
Now Alwin Dornelly is my assistant. With aid
from Durrell Wildlife [and funding grants 
from the Iguana Specialist Group and the
International Iguana Foundation], we’re now
able to do the things we always wanted to do
… doing surveys, finding out where the
population is, finding the threats where they are
nesting, and other things.

“I can say right now that we have a pretty good
handle on where the iguanas are located and a
pretty good idea as to where they are nesting, 

and I’m sure that we will get a pretty good idea
of the size of the population.”

— Donald Anthony, 
Wildlife Officer, St. Lucia

Much work remains. This is only the second year
of research and plans are in place to conduct exten-
sive observations of hatchlings on the main nesting
beach this year. With time, a much better picture
regarding the status of these lizards will emerge.

Species are disappearing at an alarming rate
and we now know that we must act immediately
when warning signs are seen. The California Giant
Condor (Gymnogyps californianus) and Spix’s
Macaw (Cyanopsitta spixii) are two high-profile
species that have disappeared in the wild. The
Grand Cayman Blue Iguana (Cyclura lewisi) also
is on the brink of extinction.

On St. Lucia, hope prevails. Enough iguanas
survive at the moment and the means by which
their numbers are being depleted are now well
known. The right people are in place to deal with
the situation. This beautiful and distinctive Green
Iguana is one of the jewels of the Caribbean —
and it deserves a future. 

Acknowledgments
I am very grateful to Matthew Morton for

providing interviews, valuable information, and
photographs. Brian James, Michael Andrew,
Donald Anthony, Alwin Dornelly, Catherine
Malone, Karen Graham, Bill Toone, and John
Hartley have read and commented on various
drafts of this article.

All illustrations © J.S. Bendon & lizardwizard 2003.
All photographs © Matthew Morton/Durrell Wildlife 2003.

78 IGUANA Volume 10, Number 3

can be congenital. However, one observer suggested
that this might simply have been an abscess.

Yet another unusual observation was made ini-
tially in nine hatchlings, all of which emerged from a
single, closely watched nest with various portions of
their tails missing. Without a stabilizing tail, these ani-
mals were a lot slower and clumsier, fishtailing from
side to side as they attempted to run. Consequently,
they were much easier to catch (and photograph).
The most likely culprit in this instance is a rat or a land
crab that burrowed into the nest, a conjecture sup-

ported by the fact that more hatchlings with missing
tail portions were subsequently observed emerging
from other nests.

Acknowledgments

Jenny Daltry (FFI), Matthias Goetz (Durrell Wildlife
Conservation Trust), Karen Graham (Sedgwick
County Zoo), Rick Hudson (Fort Worth Zoo), Jeff
Lemm (San Diego Zoo), and Juliann Sweet responded
to inquiries regarding the possible causes for the var-
ious anomalies.


