By Tami Bruin
Geographic Range
The Galapagos Land Iguana is native to the Galapagos Islands, off the coast of Ecuador. It is formerly widely distributed on these islands, though its numbers are now greatly reduced (Mattison 1989, Cogger and Zweifel, 1998).
Biogeographic Regions:
oceanic islands 
(native ); pacific ocean (native ).
Habitat
The lizards live in land burrows, which offer protection from the hot sun. Many islands on which the iguanas live are quite arid.
Terrestrial Biomes:
scrub forest .
Physical Description
The Galapagos Land Iguana is yellow or brown in color with spots throughout its ventrum and dorsum. A spikey dorsal crest runs along the neck and back. This is a large (>48 in), heavy bodied lizard, with thick back legs and smaller front legs. There are long, sharp claws on its toes. It has a short blunt head and pleurodont teeth. Its tail is quite a bit longer than its trunk. (Mattison 1989).
Some key physical features:
ectothermic ; bilateral symmetry .
Reproduction
These lizards have a mating ritual where the male agressively courts the female. Males defend territories around their burrows that both they and females use as shelter, and most courtship occurs around these burrows. Females are attracted to male's territories with burrows, but these burrows are not used for nesting. (Werner 1982).
Female Land Iguanas lay soft-shelled eggs with permeable shells. About 25 eggs are laid in burrows in moist sand or under leaf litter. On the arid, rocky island of Fernandina, females may travel more than 15 km to find good nest sites, sometimes within the crater of a dormant volcano. When places to lay eggs become scarce, competition between females occurs and some eggs already laid may be disturbed by another iguana (Werner 1983, Mattison 1989). Hatchlings appear in about three to four months, and may take about a week to dig out of the nest cavity (Terraquest 1996).
Key reproductive features:
gonochoric/gonochoristic/dioecious (sexes separate).
Food Habits
The Land Iguana is largely a vegetarian. The prickly pear cactus (Opuntia) is a major food source; the lizard eats the cactus fruit and leaves by moving the cactus around in its mouth until all the spines are worked off (Mattison 1989).
Economic Importance for Humans: Negative
No adverse effects.
Economic Importance for Humans: Positive
This species was observed by Darwin early in the 19th Century; Darwin noted its similarity to iguanas on the South American mainland, as well as its obvious adaptations to local conditions. These and other observations of Galapagos wildlife contributed in part to Darwin's theory of evolution.
Today the Land Iguanas are an important part of the unique Galapagos fauna, and studies of their biology, as well as conservation programs, are continuing.
Conservation Status
IUCN Red List: [link]:
Vulnerable.
The Galapagos Land Iguana is listed as a threatened species by the World Conservation Union (Baillie and Groombridge 1996). Threats include destruction of eggs and young lizards by introduced rats and cats, and destruction of food plants by introduced goats.
Contributors
Tami Bruin (author), Michigan State University.
James Harding 
(editor), Michigan State University.
