Galapagos land iguana: why the species is endangered



by LORENZO CIOTTI

Galapagos land iguana: why the species is endangered

IUCN has classified the Galapagos land iguana as vulnerable, due to climate change that is threatening the environment of the islands on which it lives. This iguana length varies between one and two meters, including the tail, while the weight ranges from 8 to 15 kg.

It has a round pupil, like other nocturnal reptiles, and very well developed eyelids. It has a well-developed sense of hearing and complete hearing organs, where snakes do not. The mouth allows the iguana to feed on cacti, one of the few food sources available on the islands where it lives.

The tongue is thick and wide; the legs are equipped with 5 fingers each. On the back there is a thorny crest that gradually decreases with the progressive approach to the tail, which does not enjoy autotomy. This is due to the lack of super predators and other carnivores capable of killing land iguana specimens and, therefore, the regenerative capacity of this appendix has decreased until it almost completely disappears.

As a demonstration of this fact, observations conducted on 200 specimens have brought to light that only two of them were able to regenerate a good part of them. However, each individual is capable of making it grow back, even to a minimal extent.

The scales grow upwards and subsequently outwards and are regularly replaced by new ones. The nature of this animal is mild and quiet: during the day they can be admired while they go in search of food or take their sun baths.

The usefulness of these lies in the fact that, being a heterothermic species, the terrestrial iguana, like most of the reptiles, needs external heat sources to start its fundamental vital functions and its metabolism. It is estimated that between 5,000 and 10,000 land iguanas are found in the Galápagos.

These iguanas were so abundant on Santiago Island at one time that naturalist Charles Darwin remarked when it was called King James Island that "when we were left at James, we could not for some time find a spot free from their burrows on which to pitch our single tent.

" In the years since then, entire populations have been wiped out by introduced feral animals such as pigs, rats, cats, and dogs.