Green Iguana

Green Iguana

American iguana, Iguana,

Kingdom
Phylum
Subphylum
Class
Order
Family
Genus
SPECIES
Iguana iguana
Population size
Unknown
Life Span
8-20 yrs
WEIGHT
9 kg
LENGTH
1.5-2 m

Green iguanas are large beautiful looking lizards found in the Americas. Despite their name, Green iguanas can come in different colors and types. Their color may range from green to lavender, red, orange, black, and even reddish brown. They can also be bluish in color with bold blue markings. Green iguanas have a row of spines along their backs and along their tails, which helps to protect them from predators. Their whip-like tails can be used to deliver painful strikes and like many other lizards, when grabbed by the tail, the iguana can allow it to break, so it can escape and eventually regenerate a new one. In addition, iguanas have a well-developed dewlap, which helps regulate their body temperature. This dewlap is used in courtships and territorial displays.

Distribution

The native range of Green iguanas extends from southern Mexico to central Brazil, Dominican Republic, Paraguay, and Bolivia and the Caribbean; specifically Grenada, Aruba, Curaçao, Trinidad, and Tobago, St. Lucia, St. Vincent, and Útila. They have been introduced to Grand Cayman, Puerto Rico, Texas, Florida, Hawaii, and the U.S. Virgin Islands. These lizards inhabit tropical rain forests and are often found near water. They also can be found in other types of habitat including dry forest, gallery forest, and mangroves.

Green Iguana habitat map

Climate zones

Habits and Lifestyle

Green iguanas are diurnal, arboreal lizards. They are very agile climbers, and if the lizards fall up to 50 feet (15 m) they can land unhurt (iguanas use their hind leg claws to clasp leaves and branches to break a fall). During cold, wet weather, Green iguanas prefer to stay on the ground for greater warmth. These solitary lizards usually live near water and are excellent swimmers. When swimming, an iguana remains submerged, letting its four legs hang limply against its side. They propel through the water with powerful tail strokes. When iguanas sense danger, they will usually freeze or hide.

Seasonal behavior

Diet and Nutrition

Green iguanas are naturally herbivorous reptiles. They feed on leaves, mustard greens, dandelion greens, flowers, fruit, and growing shoots of upwards of 100 different species of plant. Wild adult Green iguanas may eat birds' eggs, grasshoppers and tree snails.

Mating Habits

MATING BEHAVIOR
REPRODUCTION SEASON
dry season
INCUBATION PERIOD
10-15 weeks
INDEPENDENT AGE
at birth
BABY NAME
hatchling
BABY CARRYING
20-71 eggs

Green iguanas have a polygynandrous (promiscuous) mating system. This means that both males and females mate with multiple partners. The breeding season occurs in the dry season. During this time males tend to display more dominant behaviors, such as head bobbing and tail whipping. They also tend to develop a taller dorsal crest than females, as well as taller dorsal spines (or spikes). Females lay clutches of 20 to 71 eggs once per year during a synchronized nesting period. They give no parental protection after egg-laying, apart from defending the nesting burrow during excavation. The hatchlings emerge from the nest after 10-15 weeks of incubation. Once hatched, the young iguanas look similar to the adults in color and shape, resembling adult females more so than males and lacking dorsal spines. Juveniles stay in familial groups for the first year of their lives. Males in these groups often use their own bodies to shield and protect females from predators which makes Green iguanas to be the only species of reptile which do this. In general Green iguanas become reproductively mature when they are 2-4 years old.

Population

Population threats

Historically, Green iguana meat and eggs have been eaten as a source of protein throughout their native range, and are prized for their alleged medicinal and aphrodisiac properties. Hides of these lizards are also used producing leather. Green iguanas also suffer greatly from the international pet trade and the loss of their native habitat due to development and land conversion for grazing.

Population number

According to IUCN, the Green iguana is locally common and widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.

Ecological niche

These beautiful lizards play a very important role in the ecosystem they live in. Due to their diet, Green iguanas are very important as seed dispersers. They are also a prey species to the local predators and human. Green iguanas can also indicate changes in the environment because reptiles are more sensitive to environmental changes than humans. So if to watch their responses, people can be warned about possible problems before they become too large.

Domestication

Green iguanas are commonly found in captivity as a pet due to their calm disposition and bright colors. The American pet trade has put a great demand on these lizards. 800,000 iguanas were imported into the U.S. in 1995 alone, primarily originating from captive farming operations based in their native countries (Honduras, El Salvador, Colombia, and Panama). However, these animals are demanding to care for properly over their lifetime, and many die within a few years of acquisition.

DOMESTICATION STATUS Semi-domesticated

Fun Facts for Kids

  • The word iguana is derived from a Spanish form of the Taíno name for the species: iwana. In some Spanish-speaking countries, males of the species are referred to as "gorrobo" or "ministro" and juveniles are called "iguanita" or "gorrobito".
  • In South and Central America, the Green iguana is colloquially known as "gallina de palo" which means "bamboo chicken" or "chicken of the trees".
  • Green iguanas have excellent vision, enabling them to detect shapes and motions at long distances. They have cells called “double cone cells” that give these lizards sharp color vision and enable them to see ultraviolet wavelengths. This ability is highly useful when Green iguanas bask in the sun; this way the lizards can ensure that they absorb enough sunlight in the forms of UVA and UVB to produce vitamin D.
  • Green iguanas have a white photosensory organ on the top of their heads called the parietal eye. It is also called the third eye, pineal eye or pineal gland. This "eye" cannot form images, but is sensitive to changes in light and dark and can detect movement. This helps the iguana detect predators stalking it from above.
  • Green iguanas have very sharp teeth that are capable of shredding leaves and even human skin. These teeth are shaped like a leaf, broad and flat, with serrations on the edge. The teeth are situated on the inner sides of the jawbones, which is why they are hard to see in smaller specimens.
  • These lizards can stay underwater for up to 30 minutes.

References

1. Green Iguana on Wikipedia - https://en.wikipedia.org/wiki/Green_iguana
2. Green Iguana on The IUCN Red Liste - https://www.iucnredlist.org/species/174481/1414646

More Fascinating Animals to Learn About