THREATS

A population survey in 2002 revealed that fewer than 25 Blue Iguanas remained in the wild; the population was functionally extinct.

The biggest threat to Cyclura lewisi, throughout history has been human encroachment. Most of the species natural habitat has been cleared for agriculture or real estate development and the remaining habitat is severely fragmented and criss-crossed by roadways, where many iguanas meet their death as traffic fatalities. Introduced predators, such as rats, which eat eggs and juveniles, cats, which eat young iguanas and dogs, which can kill and eat adult iguanas have caused tremendous devastation. As recently as June 2006, wild dogs prowling in the Queen Elizabeth II Botanic Park (site of the captive breeding facility as well as a free-roaming population of released iguanas) killed two adult iguanas and maimed a third.

Grand Cayman is also home to introduced Green Iguanas, a situation that confuses public attitudes and understanding of the endangered status of the Blue Iguanas.

Common Iguanas (Iguana iguana), also known as Green Iguanas, have escaped from the domestic pet trade on Grand Cayman, and are breeding in the wild throughout the western districts of the island. They are native to Central and South America, where they evolved in the presence of many predators. Common Iguanas therefore have instinctive strategies to avoid being eaten by cats and dogs, and they are thriving in suburban areas where Blue Iguanas would not stand a chance.

Common Iguanas are now numerous and sighted often, while the critically endangered Blues are almost never seen outside protected areas. More and more, people are beginning to mistakenly assume the Common Iguana actually IS the Cayman’s own Blue Iguana!

The two species are very different, and can not breed together. They don’t even speak the same “language” – when a Blue Iguana threatens a Common Iguana by head-bobbing, the Common Iguana does not understand. Size for size, the Blue Iguana is much stronger and much more aggressive.

To tell them apart, look at these pictures, and note these characteristics:

Common Iguana has spines on the dewlap (the skin flap under the chin), The Blues never have spines here.

Common Iguanas have a very long, whip-like tail, with vivid black bands. Blues have a thicker tail, without obvious bands.

Common Iguanas have a large circular scale, like a shield, on the cheek beneath the ear. Blues have their cheeks covered with cone-shaped, pointed scales when they are old, and never have a large circular one.