Blue Iguana

Cyclura lewisi

Last updated: May 15, 2023
Verified by: AZ Animals Staff
© DnDavis/Shutterstock.com

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Blue Iguana Scientific Classification

Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Iguanidae
Genus
Cyclura
Scientific Name
Cyclura lewisi

Read our Complete Guide to Classification of Animals.

Blue Iguana Conservation Status

Blue Iguana Locations

Blue Iguana Locations

Blue Iguana Facts

Group Behavior
  • Solitary
Estimated Population Size
443
Biggest Threat
feral animals, deforestation, industrialization, urbanization
Most Distinctive Feature
Skin that ranges from dusky blue to grey
Distinctive Feature
They are axanthic, which means that they don't have any blue or yellow pigment in their skin.
Other Name(s)
Grand Cayman blue iguana
Gestation Period
65 to 90 days
Temperament
aggressive
Incubation Period
65 to 90 days
Litter Size
1-21 eggs
Habitat
dry, rocky forests; indigenous to the Cayman Islands
Diet
Omnivore
Lifestyle
  • Solitary
Favorite Food
stems and leaves, fruit and flowers
Number Of Species
1
Location
Great Cayman Islands

Blue Iguana Physical Characteristics

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The Blue iguana is a species of lizard that is currently endangered. It is native to the island of Grand Cayman.

With this lizard’s articulated toes, it can dig up things quickly and climb trees. While a mature male can be of dark grey to turquoise color, the female is more of olive green to pale blue.

Younger blue iguanas feature much different coloring that is much darker, featuring a dark brown or green hue with a darker banding uniformly. The adults can change their color to blue when they are around other iguanas to mark their territories, but they often prefer to stay on the ground. Male blue iguanas are larger than females and have more prominent dorsal crests. The axanthic blue iguanas, however, are only 10 to 14 inches in size.

Blue iguana infographic

5 Incredible Blue Iguana Facts!

Even with the many changes that other reptile species have, the blue iguana has many interesting facts that help it to stand out. Here are just a few traits that the blue iguanas exude.

  • Blue iguanas are axanthic, which means that they don’t have any blue or yellow pigment in their skin. Instead, they can only create grey, black, and brown in their complexion.
  • These iguanas are rather small, only reaching a maximum of 14 inches in length.
  • Blue iguanas don’t typically enjoy living together, opting for a more solitary life. Still, they will seek out a mate when breeding needs to occur.
  • When it comes to bedtime, the blue iguana prefers to sleep in the darkness of night, much like other iguana species.
  • Blue iguanas are incredibly territorial, showing aggression towards any threats to their habitat as young as just a few months old.
Grand Cayman Blue Iguana. Cyclura lewisi is an endangered species and is native to the Cayman islands.

Cyclura lewisi aka Grand Cayman Blue Iguana is an endangered species and is native to the Cayman Islands.

©DnDavis/Shutterstock.com



Scientific Name

The blue iguanas go by the scientific name Cyclura lewisi. They belong to the kingdom Animalia and phylum Chordata. Their class is called Reptilia, and the order is called Squamata. The suborder is Iguania, and the family is called Iguanidae. The genus is called Cyclura, and the species is called C. lewisi.

Appearance

The blue iguanas usually have skin that ranges from dusky blue to grey. They have crossbands over their bodies. The bands, however, are barely visible. The mature male’s skin color ranges from dark grey to turquoise blue while that of the females is more olive green to pale blue. Meanwhile, the young blue iguanas are uniformly dark brown or green.

The coloration gives a great camouflage advantage to these lizards. During the mating season, these lizards become a brighter blue. Like many other species, the vibrant color is more prominent and pronounced in males than in females. Males are also known to be bigger than females. They have more prominent crests as well as larger femoral pores located on their thighs, which release pheromones.

The axanthic blue iguanas are usually about 20 to 30 inches in size and weigh about 30 pounds. However, the baby blue iguanas are only 10 to 14 inches in size.

Extremely Rare Blue Iguana (Cyclura lewisi) is protected in the Queen Elizabeth II Botanic Park, where you can find the real natural habitat of this surprising creature.

The blue iguanas usually have skin that ranges from dusky blue to grey. They have crossbands over their bodies but these are barely visible.

©Blue Sky imagery/Shutterstock.com

Behavior

These Iguanas are usually solitary and come together only to breed. They are known to be active during the day and usually enjoy sleeping through the night. They love sleeping in tree cavities as well as rock holes. These lizards are terrestrial which means that they love staying on the ground, but they can climb trees that are 15 feet and higher. The younger blue iguanas are more arboreal.

Even though these lizards are known to be solitary, in captivity, they can turn pretty aggressive toward each other from an incredibly young age. They are known to get bolder and more visible as they grow in age.

The female iguanas live a solitary life most of the year. They stay homebound, close to their favorite rock holes. The females are known to defend a small territory including places to feed as well as bask. No other adult female iguanas are allowed in their territories. The message of staying away is communicated through vigorous head bobbing. If that doesn’t work, the intruder is then attacked.

The males on the other hand are less tied to one single place and often sleep in alternative holes that are usually scattered across a much larger territory. During the non-breeding season, the males are lazy and get up late. They eat a lot during this time and mask motionless for hours.

Blue iguanas can make great pets. They are sold at high prices, sometimes up to $1000. They are one of the most popular lizards that are kept as pets. However, they require a lot of attention and human care. Under human care, they can live for as many as 69 years. Usually, otherwise, their lifespan is about 25 to 40 years.

Habitat

These iguanas are native to the island of Grand Cayman. They love sleeping in tree cavities and rock holes. They prefer staying in dry, rocky forests that are situated in coastal areas. The rocky forests that they prefer may contain cacti and other plants with thorns.

Apart from that, these lizards can also be found in semi-deciduous forests, scrub woodlands, tropical forests as well as dry-to-subtropical forests. Not only that, but the blue iguanas can adapt to manmade habitats, as well.

grand-cayman-blue-iguana-eating-a-flower

Grand Cayman blue iguanas enjoy eating flowers.

©iStock.com/adogslifephoto

Diet

These iguanas are primarily herbivorous and mostly feed on stems and leaves. They also eat fruits and flowers. However, occasionally, you could spot these lizards feeding on excrement, fungi, soil as well as insects.

Reports suggest that at some zoos, these lizards are fed carrots, sweet potatoes, leafy green vegetables, and herbivorous pellets. They may also rarely feed on crabs and slugs.

Predators and Threats

These iguanas face a predation threat from feral animals. Apart from that, free-roaming dogs and cats also hunt these lizards down. They are known to kill and prey on both adults as well as young iguanas.

The baby blue iguanas and the hatchlings face predation threats from Norway rats. Human activities like deforestation, industrialization, and urbanization also pose a threat to these iguana lizards.

A baby exotic blue iguana in a person's hand.

A baby blue iguana sits in a person’s hand. Blue Iguanas can live for 25 to 40 years usually.

©Mohammad Mahfud Muzaqi/Shutterstock.com

Reproduction and Life Cycle

These iguanas are known to indulge in mating sessions from May through June. The male iguanas court the females by head bobs. After that, the males circle the females and grasp the nape of her neck.

Forty days after mating, the females dig out a nest in earth pockets. These nests in the ground are exposed to the sun. The female then lays a clutch of eggs there. The clutch can vary anywhere between one to 21 eggs. The eggs are usually laid in June or July.

Researchers say that the nests maintain a temperature of 32 degrees Celsius throughout the incubation period. The incubation period ranges from 65 to 90 days. The baby iguanas become aggressively territorial when they are about three months old. They are known to reach sexual maturity at the age of four in captivity.

Blue Iguanas are said to live for 25 to 40 years usually. However, in one case, a male iguana that was kept by people survived for about 69 years in total.

Blue Iguana isolated on blue background.

Though they are on the endangered species list, blue iguanas are making strides to grow in population.

©Elena Sherengovskaya/Shutterstock.com

Population

The IUCN Red List says that there are about 443 mature blue iguanas in the world. This species is currently categorized as endangered on the IUCN Red List. However, it has been said that the population numbers are now increasing in the world.

It has also been said that by 2003, fewer than 15 blue iguanas had remained in the wild, and by the first decade of the 21st century, the wild population was said to be extinct.

Evolution and Origin

In 1938, Charles Bernard Lewis from the Institute of Jamaica joined a Cayman Islands expedition. He obtained two blue iguanas, a male and a female. In 1940, the blue iguana was formally described as C. macleayi lewisi, though it was reclassified as C. nubila lewisi in 1975, making it a subspecies of the Cuban iguana. Changing this mistake, the blue iguana was finally reclassified as a distinct species in 2004.

Not much else is known about the evolution and origins of this lizard, other than it is indigenous to the Cayman Islands.

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About the Author

Bethany is a professional copywriter and editor, working with newspapers, small businesses, Fortune 500 companies, and everything in-between. She graduated from Penn State University with degrees in journalism and international studies. She loves her cat, Maggie, and has had numerous pets over the years, including guinea pigs, hermit crabs, fish, and a red-eared slider turtle. She lives among farmlands in southcentral PA and enjoys gardening, cooking, reading, and sewing.

Blue Iguana FAQs (Frequently Asked Questions) 

Are blue iguanas' carnivores, herbivores, or omnivores?

Blue iguanas are primarily herbivorous in nature and mostly feed on stems and leaves. They also eat fruits and flowers. Occasionally, they also eat insects, soil, crabs as well as slugs.

Are blue iguanas' good pets?

Yes, they can make good pets. They are one of the most popular pet lizards. However, they require a great deal of attention and care. Under human care, they can live up to 69 years as well.

Are blue iguanas aggressive?

The baby blue iguanas could turn out to be pretty aggressive towards each other at a noticeably young age in captivity.

How much does a blue iguana cost?

Blue iguanas are sold for high prices, sometimes up to $1000.

What is the difference between a blue and green iguana?

There is only one major difference. The blue iguanas have heavier as well as larger physical features than the green iguanas. The blue iguanas, therefore, prefer the outdoor environments way better than the green iguanas.

How big does a blue iguana get?

Barring the tails, the blue iguanas can be about 20 to 30 inches and can weigh about thirty pounds. However, the axanthic blue iguanas are only 10 to 14 inches in size.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.

Sources
  1. Animalia, Available here: https://animalia.bio/blue-iguana
  2. Smithsonian's National Zoo & Conservation Biology Institute, Available here: https://nationalzoo.si.edu/animals/grand-cayman-blue-iguana
  3. Wikipedia, Available here: https://en.wikipedia.org/wiki/Blue_iguana

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