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222 IGUANA  •  VOLUME 14, NUMBER 4  •  DECEMBER 2007 KNAPP

The Commonwealth of Dominica is believed to support the largest single population of Lesser Antillean Iguanas (Iguana delicatissima),
largely because of its expansive, undisturbed coastal habitats. 

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The Lesser Antillean Iguana (Iguana delicatissima) survives
on fewer than 10 main islands in the northern Lesser

Antilles. Historically, these iguanas probably were common on
every island from Anguilla in the north to Martinique in the
south. The contemporary range reductions are associated with
European colonization. Hunting and introduction of exotic
predators and competitors threaten Lesser Antillean Iguanas
with extinction across their range. The genetic integrity of the
species also is in jeopardy on some islands because of hybridiza-
tion with the introduced Green Iguana (I. iguana). Finally, in

tropical island systems such as those in the Caribbean, road con-
struction and subsequent development occurs primarily along
coastal areas to accommodate the tourism industry. As coastal
roads and development projects expand, I. delicatissima becomes
increasingly susceptible to road mortality during terrestrial
movements. Often such terrestrial movements are to historic
coastal nesting habitats, many of which have been severely
degraded or completely destroyed. Decades of neglect and lack
of appropriate conservation efforts have placed the Lesser
Antillean Iguana in jeopardy of extinction. In fact, populations

Ecology and Conservation 
of the Lesser Antillean Iguana 

(Iguana delicatissima)
Charles Knapp

Conservation Research Postdoctoral Fellow
Conservation and Research for Endangered Species

Zoological Society of San Diego

IGUANA  •  VOLUME 14, NUMBER 4  •  DECEMBER 2007 223IGUANA DELICATISSIMA

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Many extant populations of Lesser Antillean Iguanas have been reduced to extremely low numbers and restricted to remaining “natural” areas,
causing concern about the long-term viability of the entire species. 

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have already been extirpated from several islands (Barbuda, St.
Christopher, Nevis, Antigua, Les Îles des Saintes, Marie-Galante,
and St. Martin/St. Maarten. Moreover, many extant populations
have been reduced to extremely low numbers and restricted to
remaining “natural” areas, causing concern about the long-term
viability of the entire species. Lesser Antillean Iguanas are listed
as “vulnerable” to extinction by the IUCN (Hilton-Taylor,
2000). However, individual populations on several islands are
critically endangered and only one population (Petite Terre) is
considered stable (Powell, 2004).

Conservation and Research for Endangered Species
(CRES) at the Zoological Society of San Diego has initiated a
multiyear study of I. delicatissima in order to acquire ecological
information that can be used to make informed conservation
management decisions throughout the species’ range. Our aim
also is to raise community awareness about the plight of the
iguana, because the long-term survival of the species will require
local stewardship and pride. Our focal study population is on
the island of Dominica. The Commonwealth of Dominica is
believed to support the largest single population of I. delicatis-
sima, largely because of its expansive, undisturbed coastal habi-
tats (Day et al., 2000). This population provides an opportunity
to study the species under natural conditions prior to cata-
strophic declines and the subsequent cascading demographic
perturbations that are occurring elsewhere in the Lesser Antilles.

This study focuses initially on investigating coastal popula-
tions of I. delicatissima. Specifically, we are investigating life-his-
tory variation between disturbed and undisturbed iguana pop-
ulations. Study variables include clutch size, age to reproduction,
nest-site selection, hatching rate, juvenile and adult survival, and
diet. Because coastal features on many Lesser Antillean islands
are similar, data from “control” undisturbed and disturbed sites
can be used to predict the fate of populations on Dominica and
other islands where coastal development is increasing — prima-
rily to address the demands of tourism, which has become the
economic mainstay of many regional island nations. Road sur-
veys will be conducted to quantify current levels of road-kill

224 IGUANA  •  VOLUME 14, NUMBER 4  •  DECEMBER 2007 KNAPP

Lesser Antillean Iguanas (Iguana delicatissima) are susceptible to road
mortality during terrestrial movements, which may be associated with
historic coastal nesting habitats. 

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The population of Lesser Antillean Iguanas on Dominica provides an opportunity to study the species under natural conditions prior to cata-
strophic declines and the subsequent cascading demographic perturbations that are occurring elsewhere in the Lesser Antilles. 

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IGUANA  •  VOLUME 14, NUMBER 4  •  DECEMBER 2007 225IGUANA DELICATISSIMA

mortality and identify its impact on population sustainability
and demography. In addition to investigating life histories, we
are radio-tracking adults to acquire movement data, which will
help evaluate the impact of migrations to coastal nesting areas
and possibly mitigate concomitant road mortality. Surveys also
will be used to identify and qualify attributes of important cross-
ing points characterized by high-frequency mortality events.
Lastly, we will be radio tracking hatchlings from nests to record
dispersal and survival, and document significant natural and
invasive predators.

Working with coastal I. delicatissima populations on
Dominica provides a means to close the gap in connecting dif-
ferent landscapes using charismatic species as conservation flag-
ships. Currently on Dominica, parrots are seen as flagships for
inland mesic forests, whereas sea turtles represent beach habitat.
However, the coastal scrub areas lack such a focal species, and I.
delicatissima has charisma and conservation appeal. Additionally,
Dominica is one of the last strongholds for I. delicatissima and
the methodologies used and results garnered during this study
could be used as a model for other Lesser Antillean islands.
Furthermore, we hope to establish a conservation footprint to
spin off and replicate on other islands, using our results as lever-
age elsewhere.

Finally, iguanas are charismatic conservation ambassadors
and we expect to work with local educators to develop programs
focusing on iguanas and their importance to the island.
Educational opportunities will include the provision of hands-
on field-research experiences with students and teachers. With
permission and assistance from the Division of Forestry, we will
engage students in the classroom with educational lectures
involving study animals.

Presently, life-history information about the Lesser
Antillean Iguana is limited. This project offers an excellent
opportunity to study the iguana comprehensively in its one
remaining stronghold, use the data to educate Dominicans
about its importance, and devise conservation and management
strategies for iguana habitat throughout the region.

References
Day, M, M. Breuil, and S. Reichling. 2000. Taxon account: Lesser Antillean

Iguana (Iguana delicatissima), pp. 62–67. In: A. Alberts (ed.), West Indian
Iguanas: Status Survey and Conservation Action Plan. IUCN–The World
Conservation Union, Gland, Switzerland.

Hilton-Taylor, C. 2000. 2000 IUCN Red List of Threatened Species. IUCN–The
World Conservation Union, Gland, Switzerland.

Powell, R. 2004. Conservation of iguanas (Iguana delicatissima and I. iguana)
in the Lesser Antilles. Iguana 11:238–246.

Life-history data about Lesser Antillean Iguanas are limited. 

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Although largely arboreal, Lesser Antillean Iguanas readily forage and bask on the ground.

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Hatchlings were abundant in June.

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