Iguane Vert

Iguanas spend the vast majority of their time inactive, perched on tree branches. A study showed that a green iguana dedicates 3% of its time to reproduction, 1% to foraging, and remains inactive 96% of the time. It has no real need to move to search for food, and it eats more during wet seasons than dry seasons, adapting its consumption to food availability. They are territorial animals, and males readily leave their branches to chase off other males venturing into their territory. However, they occasionally allow young males who do not yet represent a real threat to approach. The territory typically corresponds to a single tree, but several iguanas can sometimes share a tree large enough to accommodate each of them in separate sections. Fights between males become more frequent during breeding season, with younger males challenging their elders following a well-defined ritual. The iguanas advance toward each other, with extended gulars and limbs, then begin circling, bobbing their heads and hissing, with their tails sweeping the ground in jerky movements. They then attempt to mount each other's backs, and when one succeeds, it searches the neck folds of its opponent with its wide-open mouth. The head of the dominated male turns dark green while that of its aggressor becomes white within just a few minutes. The dominant eventually bites its opponent on the back or neck before departing; the defeated male then flees to another territory. On a male's territory, there are typically around six females, who also establish a certain hierarchy through intimidation. Females can also be very aggressive, especially during egg-laying season.

The green iguana is a large lizard that typically reaches a size ranging from 1.2 to 1.6 m from snout to tail, with a mass of 3 to 5 kg maximum in males. The female is slightly smaller and measures on average 1.3 m for 1.2 to 2.6 kg. Some specimens can reach 2 m in length, making it the largest of all iguanas. The tail represents a large proportion of the total length, and the length from mouth to cloaca in a large male is approximately 45 cm. In some more arid regions of its range, such as the island of Curaçao, specimens tend to be smaller, and their body length without the tail rarely exceeds 23 to 26 cm.

The green iguana has nocturnal and arboreal habits, and often lives near a water source. It is thus particularly fond of trees located near rivers and streams, on which it rests for long hours. A study conducted in Belize showed that it was particularly fond of plants of the genus Citharexylum and mimosas, which represent respectively 50 and 30% of the perches used, while they represent only 15% of the vegetation. In suitable habitats, you can encounter up to 90 iguanas per hectare. During the cold and wet season, green iguanas prefer to remain on the ground, which is warmer. Young spend most of their time on the ground, camouflaging themselves among bushes, and can occasionally climb small shrubs. The green iguana is found at altitudes ranging from sea level to 1,000 m in Colombia. It can live in relatively arid environments such as the island of Curaçao.

This animal is herbivorous. However, younger individuals are more carnivorous and gradually become herbivorous as they age. Individuals less than two or three years old consume insects and spiders, allowing for proper growth, while adults eat green plants, sometimes adding fruits or flowers to their diet. Due to their arboreal habits, they eat primarily leaves and epiphytic plants, such as those of the genus Billbergia. The iguana catches its food with its mouth, without using its feet. Its teeth are undifferentiated and not adapted for chewing vegetation, as they consist of small pointed teeth. It simply tears them roughly into shreds before swallowing. Iguanas cannot assimilate vegetation themselves, which is composed largely of cellulose that enzymes produced by the animal's digestive system cannot break down. They must therefore rely on the microbial flora of their large intestine to degrade cellulose. Young iguanas do not possess the necessary microorganisms at birth to assimilate vegetation, and it has been shown that they eat adult feces to acquire the microflora necessary for a strictly herbivorous diet. Despite the vast diversity of foods in its diet, the green iguana is primarily herbivorous and thus requires a precise ratio of mineral intake (calcium to phosphorus ratio of one to two). Regarding captive iguanas, the benefit of including animal proteins in their diet is debated. Indeed, it is known that wild iguanas eat grasshoppers and tree snails, usually ingested along with the vegetation they consume. Furthermore, adult green iguanas sometimes eat bird eggs in the wild. Some zoologists, such as Adam Britton, believe that a diet including animal proteins is not healthy for the iguana's digestive system and could lead to long-term health problems, particularly involving the kidneys, and premature death. On the other hand, green iguanas at the Miami Seaquarium in Key Biscayne, Florida, have been observed eating dead fish, and captive-raised animals frequently consume mice without becoming ill, which somewhat discredits the first theory.